* Final volume = 400 mL * 50 = 20,000 mL = 20 L
* Final mass of CuSO4 = 0.1% of 20 L = 20 g
* Stock solution volume = 400 mL
* Stock solution mass of CuSO4 = x g
* Stock solution concentration = x/400 g/L
* Dilution ratio = 50
* Using dilution equation:
Initial concentration = Final concentration × Dilution factor
* x/400 g/L = 0.1% × 50
* x/400 = 0.005
* x = 0.005 × 400 = 0.2 g
The amount of copper sulphate required is 0.2 g. The answer is A.
The studies influence techniques of filtration, its various types, and theories involved in the rate of filtration. This topic useful for physical pharmacy students and other concerned with filtration.
The document defines filtration and clarification processes. It describes the basic components and process of filtration using a filter press. Key points include:
- Filtration separates solids from liquids using a porous medium, while clarification is used for very low solid concentrations below 1.0% w/v.
- A filter press uses alternating plates and frames with a filter medium to separate solids. Slurry enters the frames under pressure and the filtrate exits through outlets on the plates.
- Factors like particle properties, liquid properties, temperature, pressure difference, and filter media properties influence the filtration rate according to equations like Poiseuille's, Darcy's, and Kozeny-Carman
Filtration, cake filters & principles of cake filtration Karnav Rana
This document discusses filtration and cake filtration principles. Filtration is the separation of solids from a liquid suspension using a porous medium. In cake filtration, the suspended solids build up on the filter medium over time, forming a thicker cake with higher resistance. As the cake builds, the filtration rate decreases unless more pressure is applied. Common cake filters include filter presses, belt filters, and various types of vacuum filters that use a building cake to separate solids from liquids.
Filtration is any of various mechanical, physical or biological operations that separate solids from fluids by adding a medium through which only the fluid can pass. The fluid that passes through is called the filtrate.
explained about
Factors Affecting Filtration
Rate of filteration
Filter media
Classification of filter media
Industrial filters
A- Gravity filters. B- Vacuum filters
C- Pressure filters. D- Centrifugal filters.
The key factors affecting the filtration process include:
1) Properties of the liquid and solid particles such as density, viscosity, size, shape, and charge, as well as temperature.
2) Characteristics of the filter medium like surface area - higher surface area increases filtration rate.
3) Pressure differential across the filter which can be increased through gravity, applied pressure up to 1500 kPa, reducing pressure below atmospheric, or centrifugal force.
This document discusses filtration principles and parameters for process design. It defines filtration as separating solids from liquid using a porous medium, outlines key factors like filter type and cake formation. The document also describes Darcy's law governing filtration rate based on properties like pressure, area and viscosity. Process design parameters discussed include feed characterization like particle size and shape, while equipment design considerations cover throughput, filtration time and whether washing is needed.
This document provides an overview of filtration theory and processes. It defines filtration as the removal of solids suspended in a liquid by passing the liquid through a porous medium that retains the solids. Various filter types and operating mechanisms are described, including depth filtration, cake filtration, and clarification. Key factors that affect filtration rates such as pressure, viscosity, permeability, and particle size are also discussed. Dimensionless parameters important to modeling filtration like the Reynolds number are introduced.
The document discusses filtration and clarification processes. It defines filtration as separating solids from fluid using a porous medium, while clarification refers to separating solids present at low concentrations (below 1.0% w/v) from liquid. The mechanisms of filtration include straining, impingement, entanglement, and attractive forces. Factors that influence filtration rates include properties of the liquid, solids, filter medium, temperature, and operating pressure. Common filter media include rigid media, flexible media, and filter aids. Filtration finds applications in pharmaceutical, chemical, and wastewater treatment industries.
The studies influence techniques of filtration, its various types, and theories involved in the rate of filtration. This topic useful for physical pharmacy students and other concerned with filtration.
The document defines filtration and clarification processes. It describes the basic components and process of filtration using a filter press. Key points include:
- Filtration separates solids from liquids using a porous medium, while clarification is used for very low solid concentrations below 1.0% w/v.
- A filter press uses alternating plates and frames with a filter medium to separate solids. Slurry enters the frames under pressure and the filtrate exits through outlets on the plates.
- Factors like particle properties, liquid properties, temperature, pressure difference, and filter media properties influence the filtration rate according to equations like Poiseuille's, Darcy's, and Kozeny-Carman
Filtration, cake filters & principles of cake filtration Karnav Rana
This document discusses filtration and cake filtration principles. Filtration is the separation of solids from a liquid suspension using a porous medium. In cake filtration, the suspended solids build up on the filter medium over time, forming a thicker cake with higher resistance. As the cake builds, the filtration rate decreases unless more pressure is applied. Common cake filters include filter presses, belt filters, and various types of vacuum filters that use a building cake to separate solids from liquids.
Filtration is any of various mechanical, physical or biological operations that separate solids from fluids by adding a medium through which only the fluid can pass. The fluid that passes through is called the filtrate.
explained about
Factors Affecting Filtration
Rate of filteration
Filter media
Classification of filter media
Industrial filters
A- Gravity filters. B- Vacuum filters
C- Pressure filters. D- Centrifugal filters.
The key factors affecting the filtration process include:
1) Properties of the liquid and solid particles such as density, viscosity, size, shape, and charge, as well as temperature.
2) Characteristics of the filter medium like surface area - higher surface area increases filtration rate.
3) Pressure differential across the filter which can be increased through gravity, applied pressure up to 1500 kPa, reducing pressure below atmospheric, or centrifugal force.
This document discusses filtration principles and parameters for process design. It defines filtration as separating solids from liquid using a porous medium, outlines key factors like filter type and cake formation. The document also describes Darcy's law governing filtration rate based on properties like pressure, area and viscosity. Process design parameters discussed include feed characterization like particle size and shape, while equipment design considerations cover throughput, filtration time and whether washing is needed.
This document provides an overview of filtration theory and processes. It defines filtration as the removal of solids suspended in a liquid by passing the liquid through a porous medium that retains the solids. Various filter types and operating mechanisms are described, including depth filtration, cake filtration, and clarification. Key factors that affect filtration rates such as pressure, viscosity, permeability, and particle size are also discussed. Dimensionless parameters important to modeling filtration like the Reynolds number are introduced.
The document discusses filtration and clarification processes. It defines filtration as separating solids from fluid using a porous medium, while clarification refers to separating solids present at low concentrations (below 1.0% w/v) from liquid. The mechanisms of filtration include straining, impingement, entanglement, and attractive forces. Factors that influence filtration rates include properties of the liquid, solids, filter medium, temperature, and operating pressure. Common filter media include rigid media, flexible media, and filter aids. Filtration finds applications in pharmaceutical, chemical, and wastewater treatment industries.
mechanism of filtration, surface and depth filterssaqib_sulman
This document discusses filtration and provides details on various types of filtration processes. It defines filtration as the separation of solids from liquids by passing a suspension through a permeable medium. There are two main types of filtration: surface filtration where solids are deposited in a cake on the filter medium surface, and depth filtration where particle deposition occurs inside the filter medium. The rate of filtration depends on the driving force, which is the pressure differential, and the resistance to flow from factors like the filter cake, filter medium properties, and fluid viscosity.
This document provides information on filtration equipment and processes. It defines filtration and clarification, and describes the key components of filtration including the slurry, filter medium, filter cake, and filtrate. It explains the basic process of filtration using pressure differences and discusses various filtration applications. Different filtration mechanisms, types including surface and depth filtration, and factors influencing filtration are outlined. Finally, the document focuses on plate and frame filter presses, describing their construction, working principles for both filtration and washing operations, and some special provisions and uses.
Filtration is the process of separating solids from liquids by passing them through a porous medium that retains the solids but allows the liquid to pass through. There are several types of filtration equipment that operate using different mechanisms and forces like pressure, vacuum, and centrifugal force. The plate and frame filter press is a common pressure filter that operates in batches. It consists of filter plates and frames arranged alternately to form channels for slurry inlet and filtrate outlet. The slurry is filtered from the frames forming a filter cake that can also be washed during the process.
Filtration is a process that separates solids from liquids or gases using a porous medium. As the suspension passes through the medium, solids are retained while the liquid or gas passes through. Key factors that affect the filtration rate include properties of the fluid and solids, concentration of solids, filter area, and resistance of the filter medium and cake buildup. The two main types of liquid filtration are cake filtration, where particles build up on the surface of the medium, and deep bed filtration, where particles penetrate the medium pores to remove fine particles from dilute suspensions. Proper filter selection depends on required filtrate quality, throughput, and operating costs. Common industrial filters include bag, plate and frame, pressure leaf,
Filtration is a process used to separate solids from liquids or gases by passing them through a porous medium. The liquid that passes through is called the filtrate, while the solids that remain behind comprise the filter cake. Clarification is a type of filtration where the solids present are very small, below 1%. Key aspects of filtration include the feed or slurry mixture, filter medium, filtrate, and factors that influence the filtration rate such as surface area, particle size, pore size, viscosity, temperature, and pressure difference. Common filter media include filter cloth, kraft paper, felt, fabric, cartridges, glass wool, and membrane filters.
This document discusses various types of filtration processes. It begins by defining filtration as the separation of solids from a liquid suspension using a porous medium. It then describes different filter media types, including cake filters, clarifying filters, cross-flow filters, and ultrafilters. The document provides equations for calculating pressure drop and flow rate during batch and continuous filtration. It also discusses specific cases like constant pressure/rate filtration of compressible vs incompressible cakes. Finally, it describes common industrial filtration equipment like plate and frame filter presses, rotary drum filters, and shell and leaf filters.
This document discusses various mechanisms and equipment used in filtration. It provides details on:
1) Common filtration mechanisms including clarifiers, cake filters, and cartridge filters.
2) Equipment for conventional filtration such as plate and frame filters, horizontal plate filters, and rotary vacuum filters.
3) Pretreatment methods to improve filtration including heating, coagulation, flocculation, and the use of filter aids.
4) General theories for filtration including Darcy's law and equations for incompressible cake buildup.
5) Examples calculating specific cake resistance, filter area needed, and time required for filtration.
The document discusses various filtration techniques used in pharmaceutical processing. It defines filtration as the removal of solids from fluids or fluids from other fluids. Clarification can be achieved through filtration or centrifugation. There are two main reasons for these processes in pharmaceuticals: to remove unwanted particles and to collect solids as the final product. The document describes various types of filtration like solid/fluid, solid/gas, fluid/fluid filtration and their applications. It also discusses filtration theory, factors affecting filtration rate, various filter media types, filter aids, selection of filtration equipment and systems for different applications.
Filtration is a process used to separate solids from liquids or gases by passing them through a porous medium. The main objectives of filtration are to produce clean drinking water, effluent, air, and prevent furnace fouling. Key types of filters are cake filters, clarifying filters, and cross-flow filters. Cake filters separate large amounts of solids, clarifying filters remove small amounts of solids, and cross-flow filters use high liquid velocity to prevent solids buildup. Selection factors for filters include slurry properties, throughput needs, and whether the solid or liquid product is more valuable. Common filtration equipment includes rotary drum filters, plate and frame presses, and bag filters.
The document discusses various aspects of filtration and drying processes used in mineral processing. It describes how filtration separates solids from liquids using a porous medium, and identifies some key factors that affect filtration like pressure difference, pore size, and filter cake thickness. It also outlines different types of filters like pressure filters, suction filters, and cake filters. The document then covers common drying methods like rotary dryers, and whether heating is done directly or indirectly. The overall content provides an overview of solid-liquid separation and moisture removal techniques for mineral processing applications.
Filtration maybe defined as a nonthermal mechanical process in which undissolved particulates or suspended solid particles are separated from a solid liquid mixture by passing through a porous fibrous or granular permeable known as Filtration.
Filtration and filters maybe classified in a number of ways
By driving Force
By Function
By filtration Mechanism
By operating Cycle
By nature of Solid
This experiment aimed to determine how concentration affects the weight and volume of cake obtained from a plate and frame filter press, as well as the length of time needed to obtain a certain volume of filtrate. The results showed that as concentration increased, the time required to collect a set volume of filtrate also increased. A linear relationship was observed between volume of filtrate and time per volume of filtrate, with an r-squared value of 0.95, indicating these variables increased proportionally. Sources of error included possible equipment defects and variability in cake weights.
This document discusses filtration techniques used in Unani medicine. It begins by defining filtration and related terms. It then discusses factors that affect the filtration rate and different types of filter media and filter aids. Finally, it describes various filtration equipment used in Unani medicine like filter funnels, Buchner funnels, Seitz filters, filter presses, rotary filters, and vacuum filtration. The key techniques and considerations for filtration in Unani medicine are summarized in 3 sentences or less.
FILTRATION AND ITS TYPES methods of filtration SonuKumar1239
Filtration is a process that uses a medium to separate solids from liquids or gases by allowing only the fluid to pass through. There are different methods of filtration including hot filtration, cold filtration, and vacuum filtration. Hot filtration is used to prevent crystal formation when separating solids from a hot solution. Cold filtration rapidly cools a solution to form very small crystals. Vacuum filtration is preferred for small batches to quickly dry small crystals using a Buchner funnel, filter paper, Buchner flask, and vacuum source. Filtration removes particles and some microbes from water and comes in various household or point-of-use forms, but the effectiveness in reducing microbes varies depending on the type of microbe and filtration system
Depth filters capture contaminants within their structures, while membrane filters trap contaminants on their surface above the pore size. Depth filters have advantages of lower cost, higher throughput, and dirt capacity, but can experience media migration and inconsistent pore sizes. Membrane filters can achieve absolute sub-micron pore sizes and are generally integrity testable, but have lower flow rates and higher cost. Combination filters combine depth and membrane technologies to provide economical serial filtration.
Screening and-filtration in food science and technologyMuhammad waqas
Filtration is the process of separating solids from fluids by passing the fluid through a porous medium that retains the solids. There are different types of filtration including surface filtration using screens or sieves, and depth filtration where particles are retained within the tortuous paths of the medium. Filtration has various applications in industries like pharmaceuticals and wastewater treatment. Mechanical screening is used to separate materials into grades by particle size and involves vibrating screens to facilitate separation based on factors like vibration, density, and particle shape.
Mechanical separations methods include sieves or membranes that retain one component while allowing another to pass. Screening separates particles based on size alone using screens with different sized openings. The efficiency and capacity of a screen involves balancing how well it separates materials versus the mass it can process. Filtration separates solids from liquids by passing a suspension through a permeable filter medium, with different mechanisms including surface filtration that forms a filter cake and depth filtration within the filter medium.
This document discusses various filtration techniques used in pharmaceutical manufacturing. It begins by describing the mechanisms of filtration including straining and impingement. It then discusses various filter media and factors that influence the rate of filtration such as surface area, pressure, viscosity. Finally, it summarizes different types of filters including filter press, leaf filter, metafilter, cartridge filter, rotary drum filter, and membrane filter. It provides details on the construction and working of each type of filter.
mechanism of filtration, surface and depth filterssaqib_sulman
This document discusses filtration and provides details on various types of filtration processes. It defines filtration as the separation of solids from liquids by passing a suspension through a permeable medium. There are two main types of filtration: surface filtration where solids are deposited in a cake on the filter medium surface, and depth filtration where particle deposition occurs inside the filter medium. The rate of filtration depends on the driving force, which is the pressure differential, and the resistance to flow from factors like the filter cake, filter medium properties, and fluid viscosity.
This document provides information on filtration equipment and processes. It defines filtration and clarification, and describes the key components of filtration including the slurry, filter medium, filter cake, and filtrate. It explains the basic process of filtration using pressure differences and discusses various filtration applications. Different filtration mechanisms, types including surface and depth filtration, and factors influencing filtration are outlined. Finally, the document focuses on plate and frame filter presses, describing their construction, working principles for both filtration and washing operations, and some special provisions and uses.
Filtration is the process of separating solids from liquids by passing them through a porous medium that retains the solids but allows the liquid to pass through. There are several types of filtration equipment that operate using different mechanisms and forces like pressure, vacuum, and centrifugal force. The plate and frame filter press is a common pressure filter that operates in batches. It consists of filter plates and frames arranged alternately to form channels for slurry inlet and filtrate outlet. The slurry is filtered from the frames forming a filter cake that can also be washed during the process.
Filtration is a process that separates solids from liquids or gases using a porous medium. As the suspension passes through the medium, solids are retained while the liquid or gas passes through. Key factors that affect the filtration rate include properties of the fluid and solids, concentration of solids, filter area, and resistance of the filter medium and cake buildup. The two main types of liquid filtration are cake filtration, where particles build up on the surface of the medium, and deep bed filtration, where particles penetrate the medium pores to remove fine particles from dilute suspensions. Proper filter selection depends on required filtrate quality, throughput, and operating costs. Common industrial filters include bag, plate and frame, pressure leaf,
Filtration is a process used to separate solids from liquids or gases by passing them through a porous medium. The liquid that passes through is called the filtrate, while the solids that remain behind comprise the filter cake. Clarification is a type of filtration where the solids present are very small, below 1%. Key aspects of filtration include the feed or slurry mixture, filter medium, filtrate, and factors that influence the filtration rate such as surface area, particle size, pore size, viscosity, temperature, and pressure difference. Common filter media include filter cloth, kraft paper, felt, fabric, cartridges, glass wool, and membrane filters.
This document discusses various types of filtration processes. It begins by defining filtration as the separation of solids from a liquid suspension using a porous medium. It then describes different filter media types, including cake filters, clarifying filters, cross-flow filters, and ultrafilters. The document provides equations for calculating pressure drop and flow rate during batch and continuous filtration. It also discusses specific cases like constant pressure/rate filtration of compressible vs incompressible cakes. Finally, it describes common industrial filtration equipment like plate and frame filter presses, rotary drum filters, and shell and leaf filters.
This document discusses various mechanisms and equipment used in filtration. It provides details on:
1) Common filtration mechanisms including clarifiers, cake filters, and cartridge filters.
2) Equipment for conventional filtration such as plate and frame filters, horizontal plate filters, and rotary vacuum filters.
3) Pretreatment methods to improve filtration including heating, coagulation, flocculation, and the use of filter aids.
4) General theories for filtration including Darcy's law and equations for incompressible cake buildup.
5) Examples calculating specific cake resistance, filter area needed, and time required for filtration.
The document discusses various filtration techniques used in pharmaceutical processing. It defines filtration as the removal of solids from fluids or fluids from other fluids. Clarification can be achieved through filtration or centrifugation. There are two main reasons for these processes in pharmaceuticals: to remove unwanted particles and to collect solids as the final product. The document describes various types of filtration like solid/fluid, solid/gas, fluid/fluid filtration and their applications. It also discusses filtration theory, factors affecting filtration rate, various filter media types, filter aids, selection of filtration equipment and systems for different applications.
Filtration is a process used to separate solids from liquids or gases by passing them through a porous medium. The main objectives of filtration are to produce clean drinking water, effluent, air, and prevent furnace fouling. Key types of filters are cake filters, clarifying filters, and cross-flow filters. Cake filters separate large amounts of solids, clarifying filters remove small amounts of solids, and cross-flow filters use high liquid velocity to prevent solids buildup. Selection factors for filters include slurry properties, throughput needs, and whether the solid or liquid product is more valuable. Common filtration equipment includes rotary drum filters, plate and frame presses, and bag filters.
The document discusses various aspects of filtration and drying processes used in mineral processing. It describes how filtration separates solids from liquids using a porous medium, and identifies some key factors that affect filtration like pressure difference, pore size, and filter cake thickness. It also outlines different types of filters like pressure filters, suction filters, and cake filters. The document then covers common drying methods like rotary dryers, and whether heating is done directly or indirectly. The overall content provides an overview of solid-liquid separation and moisture removal techniques for mineral processing applications.
Filtration maybe defined as a nonthermal mechanical process in which undissolved particulates or suspended solid particles are separated from a solid liquid mixture by passing through a porous fibrous or granular permeable known as Filtration.
Filtration and filters maybe classified in a number of ways
By driving Force
By Function
By filtration Mechanism
By operating Cycle
By nature of Solid
This experiment aimed to determine how concentration affects the weight and volume of cake obtained from a plate and frame filter press, as well as the length of time needed to obtain a certain volume of filtrate. The results showed that as concentration increased, the time required to collect a set volume of filtrate also increased. A linear relationship was observed between volume of filtrate and time per volume of filtrate, with an r-squared value of 0.95, indicating these variables increased proportionally. Sources of error included possible equipment defects and variability in cake weights.
This document discusses filtration techniques used in Unani medicine. It begins by defining filtration and related terms. It then discusses factors that affect the filtration rate and different types of filter media and filter aids. Finally, it describes various filtration equipment used in Unani medicine like filter funnels, Buchner funnels, Seitz filters, filter presses, rotary filters, and vacuum filtration. The key techniques and considerations for filtration in Unani medicine are summarized in 3 sentences or less.
FILTRATION AND ITS TYPES methods of filtration SonuKumar1239
Filtration is a process that uses a medium to separate solids from liquids or gases by allowing only the fluid to pass through. There are different methods of filtration including hot filtration, cold filtration, and vacuum filtration. Hot filtration is used to prevent crystal formation when separating solids from a hot solution. Cold filtration rapidly cools a solution to form very small crystals. Vacuum filtration is preferred for small batches to quickly dry small crystals using a Buchner funnel, filter paper, Buchner flask, and vacuum source. Filtration removes particles and some microbes from water and comes in various household or point-of-use forms, but the effectiveness in reducing microbes varies depending on the type of microbe and filtration system
Depth filters capture contaminants within their structures, while membrane filters trap contaminants on their surface above the pore size. Depth filters have advantages of lower cost, higher throughput, and dirt capacity, but can experience media migration and inconsistent pore sizes. Membrane filters can achieve absolute sub-micron pore sizes and are generally integrity testable, but have lower flow rates and higher cost. Combination filters combine depth and membrane technologies to provide economical serial filtration.
Screening and-filtration in food science and technologyMuhammad waqas
Filtration is the process of separating solids from fluids by passing the fluid through a porous medium that retains the solids. There are different types of filtration including surface filtration using screens or sieves, and depth filtration where particles are retained within the tortuous paths of the medium. Filtration has various applications in industries like pharmaceuticals and wastewater treatment. Mechanical screening is used to separate materials into grades by particle size and involves vibrating screens to facilitate separation based on factors like vibration, density, and particle shape.
Mechanical separations methods include sieves or membranes that retain one component while allowing another to pass. Screening separates particles based on size alone using screens with different sized openings. The efficiency and capacity of a screen involves balancing how well it separates materials versus the mass it can process. Filtration separates solids from liquids by passing a suspension through a permeable filter medium, with different mechanisms including surface filtration that forms a filter cake and depth filtration within the filter medium.
This document discusses various filtration techniques used in pharmaceutical manufacturing. It begins by describing the mechanisms of filtration including straining and impingement. It then discusses various filter media and factors that influence the rate of filtration such as surface area, pressure, viscosity. Finally, it summarizes different types of filters including filter press, leaf filter, metafilter, cartridge filter, rotary drum filter, and membrane filter. It provides details on the construction and working of each type of filter.
Filtration is used to separate solids from liquids using a filter medium. There are two main types of filtration: dead-end filtration where flow is perpendicular to the membrane, and cross-flow filtration where flow is parallel. Selection of the proper filtration method requires experimentation. Filtration rate can be increased by increasing filter area, pressure, or reducing cake resistance. Filtration theory uses equations like Darcy's law to describe flow through a filter cake and predict filtration rates.
This document discusses various types of industrial filtration processes. It begins by defining filtration and clarification. It then covers the mechanisms of filtration, including straining, impingement, entanglement, and attractive forces. It describes types of filtration like surface filtration and depth filtration. Theories of filtration are discussed, including Poiseuille's equation, Darcy's equation, and the Kozeny-Carman equation. Factors influencing filtration and different pressure and vacuum filtration methods are also summarized, such as plate and frame filters, leaf filters, automatic belt filters, chamber filter presses, and vacuum filters.
Filtration is a process used to separate solids from liquids by passing the mixture through a porous medium that retains the solids. There are several mechanisms and theories that describe how filtration works, including straining, impingement, and Poiseuille's equation which relates flow rate to pressure difference, resistance, and other factors. Common types of filtration include surface filtration and depth filtration. Key filtration equipment includes plate and frame filters, filter leaves, and cartridge filters, which separate solids using pressure or vacuum and provide advantages like large processing areas and efficient washing.
This document provides an overview of filtration, including definitions, terms, processes, mechanisms, theories, factors influencing filtration, filter media, filter aids, classifications of filtration equipment, and plate and frame filter presses. Filtration is defined as the separation of solids from fluids by passing them through a porous medium. Key points covered include common filtration mechanisms like sieving and straining, Darcy's and Kozeny-Carman equations describing filtration rates, and factors like pressure, surface area, viscosity, and properties of solids and liquids. Common filter media like woven materials, membranes, and granular solids are also described.
Filtrasi is a separation method used to separate solid particles suspended in a fluid by passing the fluid through a porous medium that retains the solid particles. During filtration, the solid particles accumulate on the filter medium forming a filter cake that increases in thickness and resistance over time. There are different types of filtration equipment that operate using different principles like pressure, vacuum, or gravity depending on the application and amount of material being filtered. Common applications of filtration include separating brewed coffee from grounds using a paper filter, removing dust and particles from air using HEPA filters, and purifying water and sewage at municipal treatment plants.
Objectives, applications & Theories in FILTRATIONAkankshaPatel55
Filtration is a physical separation process that separates solid matter and fluid from a mixture using a filter medium that has a complex structure through which only the fluid can pass. Solid particles that cannot pass through the filter medium are described as oversize and the fluid that passes through is called the filtrate. Oversize particles may form a filter cake on top of the filter and may also block the filter lattice, preventing the fluid phase from crossing the filter, known as blinding. The size of the largest particles that can successfully pass through a filter is called the effective pore size of that filter.
Filtration is used in many different applications, including:
Water treatment: to remove impurities from water, such as sediment, bacteria, and viruses.
Air filtration: to remove dust, pollen, and other allergens from air.
Oil filtration: to remove impurities from oil, such as dirt, metal shavings, and water.
Chemical processing: to separate solids from liquids in chemical reactions.
Food and beverage processing: to clarify liquids, such as juice, wine, and beer.
There are many different types of filters, each with its own advantages and disadvantages. Some common types of filters include:
Depth filters: These filters are made of a thick layer of material, such as paper, cloth, or sand. The solid particles are trapped in the pores of the filter medium.
Surface filters: These filters are made of a thin layer of material, such as a membrane. The solid particles are trapped on the surface of the filter medium.
Cartridge filters: These filters are self-contained units that can be easily replaced.
Bag filters: These filters are made of a bag of fabric that is suspended in a housing. The solid particles are trapped in the fabric of the bag.
Filtration is commonly the mechanical or physical operation which is used for the separation of products like solids from fluids by interposing a medium through which only the fluid can pass.
The document discusses filtration and clarification processes. Filtration is defined as the separation of solids from fluids by passing them through a porous medium, while clarification involves separation of very low concentration solids (<1% w/v). Key terms like filter, filtrate, and filter cake are introduced. Common filtration mechanisms like straining, impingement, and entanglement are described. Factors affecting filtration rate include properties of solids, liquids, temperature, pressure, and filter media. Common filter media include woven materials, membranes, sintered materials and filter aids like diatomaceous earth and perlite. Theories like Poiseuille's and Darcy's laws are discussed in relation to modeling filtration rates
1. Filtration is used to separate solids from liquids using a porous medium, and is affected by factors like thickness of the filter medium, viscosity of the fluid, pressure difference, and area.
2. Darcy's equation quantifies the factors that affect filtration rate. Methods to increase rate include increasing pressure/area or decreasing thickness/viscosity.
3. Filter aids like diatomaceous earth are added to improve flow rate and decrease cake thickness. They are commonly used in pharmaceutical, chemical and food industries.
4. Key filtration methods are gravity, vacuum, centrifugal and pressure filtration. Filter presses use pressure and plates to filter large volumes.
This document discusses cell separation methods used in downstream processing. It describes filtration and centrifugation as the two main methods. For filtration, it explains the theory and types of filters used like plate and frame, pressure leaf, and rotary vacuum filters. For centrifugation, it outlines stock's law and describes basket, tubular bowl, solid bowl (decanter), multi-chamber, and disc bowl centrifuges. Cross flow filtration is also introduced as an alternative to overcome issues with other filtration methods. In under 3 sentences, this document provides an overview of cell separation techniques used in downstream processing and discusses filtration and centrifugation methods in detail.
This document discusses various concepts in fluid filtration, including:
- General definitions of filtration terms and classifications including by driving force, filtration mechanism, objective, operating cycle, and nature of solids.
- Strainers including area-type (wire mesh, metal screen, porous metal/non-metallic filters) and edge-type (metallic or paper disk elements)
- Paper or fabric filters including extended area pleated paper elements and their uses and limitations.
- Depth filters which rely on a porous material mass and can include absorbent or adsorbent effects in addition to mechanical blocking/straining.
- Absorbent filters which remove coarser and finer contaminants through
The document discusses various filtration methods and terms used in filtration. It describes different types of filtration processes like clarification, ultrafiltration, and cake filtration. It also discusses factors affecting filtration rate and various filter media used including filter paper, woven materials, membranes, and sintered glass. Different types of filters are also summarized like gravity filters, vacuum filters, pressure filters, and centrifugal filters. Rotary vacuum filters and pressure filters are described in more detail.
This document discusses different types of filtration equipment used in industrial processes. It describes the plate and frame filter press, which consists of alternating plates and frames that allow slurry to pass through a filter medium and collect filtrate. It also describes the metafilter or edge filter, which uses stacked metal rings to form channels for filtration. Finally, it discusses the filter leaf, which uses a framed filter cloth to filter slurry by applying a vacuum.
This document discusses mud filtration experiments. It aims to monitor the rate of fluid loss from a filter press under controlled conditions and measure the thickness of residue deposited on the filter paper. Filtration properties are important for understanding invasion into porous formations and filter cake buildup on wellbores. The experiment uses a standard filter press to test mud samples under static and dynamic filtration conditions at varying temperatures and pressures. Results like fluid loss volume and filter cake thickness indicate how much water/oil wetting and permeability damage may occur in formations. Formation damage can reduce productivity and is affected by factors like filter cake properties, filtrate invasion, and drilling/completion operations.
The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
Discover the Simplified Electron and Muon Model: A New Wave-Based Approach to Understanding Particles delves into a groundbreaking theory that presents electrons and muons as rotating soliton waves within oscillating spacetime. Geared towards students, researchers, and science buffs, this book breaks down complex ideas into simple explanations. It covers topics such as electron waves, temporal dynamics, and the implications of this model on particle physics. With clear illustrations and easy-to-follow explanations, readers will gain a new outlook on the universe's fundamental nature.
Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
How to Make a Field Mandatory in Odoo 17Celine George
In Odoo, making a field required can be done through both Python code and XML views. When you set the required attribute to True in Python code, it makes the field required across all views where it's used. Conversely, when you set the required attribute in XML views, it makes the field required only in the context of that particular view.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
2. Qn No.
in Exam
paper
Expected Answer
1.1 Write a critical note on (i) the law governing filtration rate and factors affecting it
(ii) any one continuous-vacuum filter with reference to its construction,
operation, advantage, disadvantage and application.
[P10:4,25,28,26,27,103,104,105]
Filtration is a mechanical or physical operation which is used for the
separation of solids from fluids (liquids or gases) by interposing a
medium through which only the fluid can pass. Oversize solids in the
fluid are retained, but the separation is not complete; s
contaminated with some fluid and filtrate will contain fine particles
(depending on the pore size and filter thickness).
The factors which affect the rate of filtration is expressed by Darcy’ s Law
FACTORS AFFECTING RATE OF FILTRATION
A. Area of surface filter
B. Particle size of the solids to be removed
C. Pore size of the filter media
D. Resistance of the filter cake and filter media
E. Viscosity of the liquid to be filtered
F. Temperature
G. Pressure difference across the filter
1. Properties of the filter medium and filter cake
The resistance of the filter medium and filter cake is denoted by R. The resistance
of filter medium is of less significance in industrial scale than the resistance of
filter cake. The latter increases with time. The rate of f
thickness of the cake increases. When the rate is uneconomically low the
filtration is stopped and the cake is removed mechanically; and the filtration is
resumed.
2
on (i) the law governing filtration rate and factors affecting it
vacuum filter with reference to its construction,
operation, advantage, disadvantage and application.
[P10:4,25,28,26,27,103,104,105] [P10:102, 64-98]
is a mechanical or physical operation which is used for the
separation of solids from fluids (liquids or gases) by interposing a
medium through which only the fluid can pass. Oversize solids in the
fluid are retained, but the separation is not complete; solids will be
contaminated with some fluid and filtrate will contain fine particles
(depending on the pore size and filter thickness).
The factors which affect the rate of filtration is expressed by Darcy’ s Law
FACTORS AFFECTING RATE OF FILTRATION
Area of surface filter
Particle size of the solids to be removed
Pore size of the filter media
Resistance of the filter cake and filter media
Viscosity of the liquid to be filtered
Pressure difference across the filter
filter medium and filter cake
The resistance of the filter medium and filter cake is denoted by R. The resistance
of filter medium is of less significance in industrial scale than the resistance of
filter cake. The latter increases with time. The rate of filtration decreases as the
thickness of the cake increases. When the rate is uneconomically low the
filtration is stopped and the cake is removed mechanically; and the filtration is
Marks
on (i) the law governing filtration rate and factors affecting it
vacuum filter with reference to its construction,
is a mechanical or physical operation which is used for the
separation of solids from fluids (liquids or gases) by interposing a
medium through which only the fluid can pass. Oversize solids in the
olids will be
contaminated with some fluid and filtrate will contain fine particles
The factors which affect the rate of filtration is expressed by Darcy’ s Law
The resistance of the filter medium and filter cake is denoted by R. The resistance
of filter medium is of less significance in industrial scale than the resistance of
iltration decreases as the
thickness of the cake increases. When the rate is uneconomically low the
filtration is stopped and the cake is removed mechanically; and the filtration is
8
3. 3
The resistance also depends on the properties of the solids, e.g. particle size,
particle size distribution, particle shape, and compressibility of the solid. In case
of compressible cake the porosity decreases with increasing pressure drop, so
filter aids are incorporated to increase the filtration rate.
2. Area of filter
The rate of filtration can be increased by increasing the area of filtration. This
area can be increased by using larger filters or by using a number of small units
in combination. In rotary filters the filter cake is continuously removed
providing an infinite area of filtration.
3. Pressure drop
Rate of filtration can be increased by increasing the pressure drop across the
filter medium. Pressure drop can be achieved by (i) gravity, (ii) negative
pressure (reduced pressure or under vacuum), (iii) positive pressure and (iv)
centrifugal force.
Gravity: The height of the slurry over the filter medium gives pressure under
gravity. By increasing the height of the slurry the pressure drop can be
increased.
Negative pressure: The pressure below the filter medium can be reduced below
atmospheric pressure by connecting the filtrate receiver to a vacuum pump.
The disadvantage of this method is that the pressure drop can never be increased
above one atmospheric pressure.
The second disadvantage is that under reduced pressure the boiling point of
liquid is lowered and the liquid may boil in the filtrate receiver that may cause
loss of liquid or may damage the vacuum pump.
Positive pressure: The simplest method of raising the pressure difference across
the filter membrane is to increase the pressure to the surface of the slurry.
The advantage is that greater pressure difference can be achieved.
Centrifugal force: The gravitational force can be increased by centrifugal force.
4. Viscosity of liquid
An increase in the viscosity of the liquid will decrease the flow rate. The
viscosity of the liquid can be decreased by raising the temperature of the slurry
or by dilution with a miscible liquid.
5. Thickness of the filter cake
Thickness of the filter cake increases as the filtration progresses. Highly
concentrated slurry is first decanted or strained to reduce the solid content and
then it is filtered (this reduces the cake thickness). In a rotary drum filter cake is
removed continuously so that the cake thickness is minimized.
4. 4
Rotary drum filters consist of a perforated metal drum wrapped with a
filter cloth to act as filter medium
The drum is partially immersed in the tank containing the slurry. The
drum is rotated at a slow speed and vacuum is created. Thus the filtrate
will enter the drum through the filter media and filter cake will be
deposited on the outer surface of the filter medium
The cake can be removed by scrapping with a knife just before the
rotating drum repeats another cycle.
Zone Position operation
Cake Formation
Zone
(Pick-up)
Slurry
trough with
agitator
The drum picks up the slurry as soon as
it comes in contact with the slurry
trough. Cake builds up on the filter cloth
Cake Predrying
Zone
Drainage
filtrate
receiver
Under vacuum the filtrate is received in
filtrate receiver
Cake Washing
Zone
Washing
Wash sprays Water is sprayed on the cake and
simultaneously drainage is taking place.
5. 5
Cake Final Drying
Zone
Drying
Drying or
Hot Air
blower
Under vacuum the filter cake is dried.
Cake Discharge
Zone
Cake removal
Scrapper
knife
Vacuum is reversed i.e. Compressed air is
passed to this zone so that the cake may
be loosen
Dead Zone Cycle repeats
The cake discharge may be carried out by:
(i) Scrapper discharge
In this method a knife is fitted to scrap a small thickness of the pre-coat along
with the cake. But wear and tear on the filter cloth is considerable with scrapper
knife so the cloth is frequently changed.
(ii )String discharge
Numbers of endless strings are placed at about ½ inch pitch over the width of
the drum. The run or this string is extended from an open conveyor system
passing over a discharge and return roller. As compared to scrapper, the wear of
filter cloth is minimized.
(iii)Belt discharge
It makes the filter cloth to pass on the roller and material is discharged on the
first roll and before its passage to the fed trough it is subjected to washing.
Therefore, higher filtration rates may be achieved using belt discharge.
Advantages
(i) It is automatic and continuous; labor cost is low.
(ii) Very high capacity. (iii) Thick slurries containing 15–30% of solids can be
filtered. (iv) Variation of speed of rotation enables the cake thickness to be
controlled. E.g. For solids forming impenetrable cakes thickness is kept constant
within 5 mm. For porous cakes thickness is kept within 100mm.
Disadvantages
(i) Complex design with many moving parts. (ii) Very expensive.
(iii) The cake tends to crack under vacuum, so washing and drying are not
efficient. (iv) As vacuum is applied, it is unsuitable for liquids near boiling point.
(v) Gelatinous or slimy precipitates forming impenetrable cake will not separate
cleanly from cloth.
Application
(i) Collection of calcium carbonate, magnesium carbonate, starch.
(ii) Separation of the mycelium from the fermentation liquor in the manufacture
of antibiotics.
7. 7
Qn No.
in Exam
paper
Expected Answer Marks
1.2 Explain the working principle of a planetary mixer. Discuss how vortex
formation can be controlled in mixing tanks.
[4MY2828.doc, Mixing and homogenization.pdf pg186] [4MY7070.doc]
(i) Planetary motion mixers:
Construction: It consists of a circular base. Inside the container a blade rotates around its own
axis. The axis of the blade again rotates along a shaft. Thus the motion of the blade is similar to
the motion of a planet around the sun. The planet is rotating along its own axis and at the same
time the planet is rotating around the sun. The design of the blade is as shown in the figure.
There is very little clearance between the blade and the wall of the container.
Working: This design allows the revolving blade to handle (mix) a small amount of mass at a
time. Again the blade is moving, carrying the mass to other places. The blade is scraping the
materials those are sticking to the wall of the container.
Application:
1. This sturdy (strong) mixer is used to mix semisolid ointments.
2. To prepare tablets the powder is mixed with binder solutions. During this wet massing step
planetary mixer is used.
Vortexing and its remedies:
If the tangential component is dominant, a vortex forms and may deepen until it reaches the
impeller, and aeration occurs. Due to the high speed of the propellers vortexing and finally
aeration may occur; i.e. air may get entrapped which may be difficult to remove from the
product and the air may encourage oxidation in some cases, causes blade to be less in contact
with liquid, therefore decrease efficiency of mixing.
To avoid vortexing the following strategies can be worked out:
(i) The propeller should be deep into the liquid and [fig (a)]
(ii) Symmetry should be avoided:
(a) propeller shaft may be off-set from the center. [fig (b]
(b) propeller shaft may be mounted at an angle to the vertical wall of the container. [fig
(c)]
(c) the shaft may enter side of the vessel [fig (d)]
(d) or, a vessel other than cylindrical may be used, (N.B. although this is liable to give
4
Container
Blade
Shaft
Fig. Planetary mixer
8. 8
rise to ‘dead spots’ in corners)
(iii) A push-pull type of propeller may be used in which two propellers of opposite pitch are
mounted on the same shaft so that the rotating effects are in opposite directions and cancel
each other. [fig (e)]
(iv) One or more baffles may be used which are usually vertical strips attached to the wall of the
vessel. [fig (f)]
fig (a) fig (b)
fig (c) fig (d)
fig (e)
fig (f)
9. 9
Qn No.
in Exam
paper
Expected Answer Marks
2.1 Outline the classification of pharmaceutical dosage forms according to time-
release of drug. Critically compare and contrast key features of routes of
administration that bypass the first pass metabolism.
Drugs are rarely administered in their original pure state. They are converted
into suitable formulations which are called dosage forms. Every dosage form is a
combination of the drug and other non-drug components. The non-dug
components are known as “additives”. The additives are used to give a
particular shape to the formulation, to increase its stability and also to increase
its palatability as well as to give more elegance to the preparation.
According to drug release rate from the tablet :
a- Immediate-release tablet:
The tablet is intended to be released rapidly after administration, or the tablet is
dissolved and administered as solution. It is the most common type and
includes:
1- Disintegrating tablet (conventional or plain tablet)(with or w/o sugar, film
coating)
2- Chewable tablets
3- Effervescent tablets
4- Sublingual and Buccal tablets
5- Lozenges, Troches
Tablets for oral ingestion; Tablets for use in oral cavity; Tablets to prepare
solutions
b- Modified-release tablet:
They have release features based on; time, course or location. They must be
swallowed intact.
(1) Repeat -act ion tablets are layered or compression-coated tablets in
which the outer layer or shel l rapidly disintegrates in the stomach (e.g. ,
Repetabs, Scher ing; Extentabs, Wyeth) . The components of the inner layer
or inner tablet are insoluble in gast ric media but soluble in intestinal media.
(2) Delayed-act ion and enter ic-coated tablets delay the release of a drug
f rom a dosage form. This delay is intended to prevent dest ruct ion of the
drug by gast ric juices, to prevent i rr i tat ion of the stomach l ining by the
drug, or to promote absorpt ion, which is better in the intestine than in the
stomach.
Enter ic-coated tablets are coated and remain intact in the stomach, but yield
thei r ingredients in the intestines (e.g. , Ecotr in, GSk). Enteric-coated tablets are
a form of delayed-act ion tablet . However , not all delayed-action tablets are
enter ic or are intended to produce an enteric ef fect . Agents used to coat these
6
10. 10
tablets include fats, fatty acids, waxes, shel lac, and cellulose acetate phthalate.
(3) Other Sustained- release forms grouped according to their pharmaceutical
mechanism.
a. Coated beads or granules
b. Microencapsulat ion
c. Mat r ix tablets
d. Osmotic systems
e. Ion-exchange resins
f . Complex formation
When a drug is administered by oral route, it undergoes attack by gastric juices
and undergoes first pass metabolism when absorbed into the entero-hepatic
circulation, where a great fraction of it is rendered inactive. Some prodrugs are
converted to the active drug by the same mechanism.
Routes that bypass the first pass metabolism are sublingual, rectal, parentral,
transdermal and respiratory routes.
Sublingual route:
The drug diffuses into the blood, directly through tissues under the tongue in
case of sublingual tablets and through oral mucosa in case of buccal tablets.
Adv: Bypass first pass metabolism, Rapid action achieved
Eg: nitroglycerin sublingual tablet for relief of angina
Rectal route:
Suppositories administered rectally melt and dissolve to provide local action or
achieve systemic absorption.
Adv: Useful when oral administration is inappropriate, as with infants,
debilitated or comatose patients, and patients who have nausea, vomiting, or
gastrointestinal disturbances. Bypass first pass metabolism to some extent
except where upper hemorrhoidal veins are involved.
Dis: Uncertain/unpredictable absorption, local irritation and possible accidental
loss of the medication.
Parentral route:
Preparations injected directly into body tissue through the primary protective
systems of the human body, the skin and mucous membranes must be
exceptionally pure and free from contaminants.
Adv: Immediate action; Dose can be adjusted accurately; useful for unconscious,
uncoorporative patient, for drugs with poor oral absorption.
Dis: require aseptic conditions, pain factor, risk of local irritation, difficulty in
correcting the error.
11. 11
Respiratory route: preparations are inhaled for local action or systemic action.
Advantages: rapid onset of action; bypass the hepatic circulation; avoidance of
degradation in the gastrointestinal tract; lower dosage that minimizes adverse
reactions; simple, convenient and acceptable therapy.
Transdermal route: Preparations applied are absorbed through skin and provide
local and systemic action.
Adv: transdermal delivery systems provide long term systemic delivery.
Eg antianginals, analgesics(Durogesic), contraceptives
12. 12
Qn No.
in Exam
paper
Expected Answer Marks
2.2 (i) Which of the following amounts of copper sulphate is required to make
400 mL of an aqueous stock solution, such that, when the stock solution is
diluted 50 times with water, a final solution of 0.1% w/v copper sulphate is
produced?
A 0.2 g B 20.0 g C 0.4 g D 40.0 g E 50.0 g
Final conc.=0.1%w/v
Dilution factor=50
Stock conc.=0.1 x 50 = 5%w/v
100ml stock contains 5g CuSO4
400ml stock contains 20gCuSO4
Ans: B
(ii) You have in your pharmacy a cream containing 0.05% w/w Clobetasone.
You have been requested to use this cream as a base and to add in sufficient
miconazole such that the final concentration of miconazole in the new cream
will be 2.0% w/w. What is the concentration of Clobetasone in the new
cream?
A 0.025% w/w B 0.49% w/w C 0.5% w/w D 0.05% w/w E 0.049%
w/w
0 (100-2) 98
2
100 -(0-2) 2
98part cream + 2part miconazole powder=100part mixture
100g newcream contains 98gcream and 2gmiconazole
0 (0.05-x) 2
X
0.05 (x) 98
12part miconazole powder (containing 0%w/w colbetasone) when added to 988
parts 0.05%w/w colbetasone cream dilutes colbetasone to a final concentration
of X%w/w.
(0.05-x)/x=2/98
98(0.05-x)=2x
4.9-98x=2x
8
13. 13
4.9=100x
X=0.049
New cream contains 0.049%w/w colbetasone.
Ans:E
(iii) Toxic residues are sometimes found in drinking water in industrial areas.
For compound Z, the safe limit for drinking water is 92 ppm. Analytical
results for the amount of compound Z in the drinking water of various
locations are given below. Which ONE of the following locations has
drinking water that is NOT safe to drink?
A Toome: 41.0 micrograms/mL
B Blackhill: 0.3 mg/L
C Drumhowan: 0.0045% w/v
D Magheracloone: 0.00041 g/ml
E Annagassan: 1 in 100 000
Toome: 41 micrograms/mL = 41 mg/1000 mL = 41 g in
1 000 000 mL or 41 ppm
41 ppm < 92 ppm, so the water in Toome is drinkable
Blackhill: 0.3 mg/L = 0.3 mg/1000 mL = 0.3 g/1000 000 mL or
0.3 ppm
0.3 ppm < 92 ppm, so the water in Blackhill is drinkable
Drumhowan: 0.0045% w/v = 0.0045 g/100 mL = 0.045 g/1000 mL =
45.0 g/1000 000 mL or 45 ppm
45 ppm < 92 ppm, so the water in Drumhowan is drinkable
Magheracloone: 0.00041 g/ mL = 0.41 g/1000 mL =
410.0 g/1000 000 mL or 410 ppm
410 ppm > 92 ppm, so the water in Magheracloone is not drinkable
Annagassan: 1 in 100 000 is the same as 10 in 1000 000 or 10 ppm
10 ppm< 92 ppm, so the water in Annagassan is drinkable.
Ans:D
(iv) Match the comments in I) II) III) to the appropriate answer from A to E.
I) The volume of an oral liquid medicine, available as 2 mg drug X/5 mL,
which is required for a 14-day supply for a patient prescribed a dose of 4 mg
drug X three times daily.
14. 14
II) The volume of alcohol 95% v/v needed to produce 1.90 L of 50% v/v.
III) The volume of concentrated peppermint water required to make 16.8 L of
single-strength peppermint water. (Single-strength peppermint water is 1
part concentrate to 39 parts water.)
A 100 mL B 1000 mL C 4200 mL D 420 mL E 4.2 mL
I) D
The patient requires 4 mg drug X three times daily, so needs 12 mg/day. If
the drug is formulated at 2 mg/5 mL, then 6 × 5 mL doses are required per
day. If the patient, therefore, needs 30 mL/day for 14 days, 420 mL are
required. Accordingly, the correct answer is D.
II) B
1.90 L of 50% v/v contains 0.95 L alcohol
95% v/v contains 95 mL alcohol in 100 mL. Therefore, the volume of
alcohol 95% v/v containing 0.95 L alcohol can be calculated as follows:
(0.95/95) × 100 = 1.00 L or 1000 mL.
Accordingly, the correct answer is B.
III)D
For every 40 mL single-strength peppermint water you have 1 mL
concentrate. Therefore in 16.8 L, or 16 800 mL, you have 16 800/40 =
420 mL.
Accordingly, the correct answer is D.
15. 15
Qn No.
in Exam
paper
Expected Answer Marks
3.1 Classify extraction methods and compare them. Explain soxhelation with a
diagram. Comment on the merits and demerits of continuous hot percolation.
[P7:15, P7B:1], [P7B:14, P7:16] [P7:29-31, P7B:4-5]
Extraction refers to processes for the isolation of the active ingredients from drug
material. This may be by physical means or by dissolving in a suitable solvent.
-Expression is the physical act of applying pressure to squeeze out oils or juices
from plants. This was normally achieved with a tincture(hydraulic) press
-Cold Methods: Maceration, Percolation and Infusion (used for thermolabile
components)
-Hot Method: Decoction, Hot Continuous Extraction, Distillation
Extraction
method
Time for
extraction
Temperature Characteristics of the active
constituents
Maceration
Percolation
Digestion
Infusion
Decoction
3-7 days
24 hours
Few days
Short period
15 mins
Room temp
Room temp
Moderately high
Cold or boiling
water
Boiling water
• Soluble in the menstruum
• Heat stable / unstable
• Soluble in the menstruum
• Heat stable / unstable
• Heat stable
• Readily soluble
• Water soluble
• Heat stable
Or
8
EXTRACTION PROCESSES
INFUSION DECOCTION MACERATION /
DIGESTION
PERCOLATION
Fresh
Infusion
Concentrated
Infusion
Simple
Maceration
Maceration with
adjustment
Multiple
Maceration
Double
Maceration
Triple
Maceration
Simple
Percolation
Continuous
Hot Percolation
(Soxhlation)
Percolation
Process for
Conc. Preparation
Reserved
Percolation
Modified
Percolation
.
17. 17
soxhelation
Classic techniques for the solvent extraction of active
constituents from medicinal plant matrices are based
on the choice of solvent coupled with the use of heat
or agitation. Existing classic techniques used to
obtain active constituents from plants include:
Soxhlet, hydrodistillation and maceration with an
alcohol-water mixture or other organic solvents.
Soxhlet extraction is a general and well-established
technique, which surpasses in performance other
conventional extraction techniques except for, in
limited fields of application, the extraction of
thermolabile compounds.
In a conventional Soxhlet system, as shown in
Figure above, plant material is placed in a thimble-
holder, which is filled with condensed fresh solvent
from a distillation flask. When the liquid reaches the
overflow level, a siphon aspirates the solution of the
thimble-holder and unloads it back into the
distillation flask, carrying extracted solutes into the
bulk liquid. Solute is left in the fl ask and fresh
solvent passes back into the plant solid bed. The
operation is repeated until complete extraction is
achieved.
This process is used for those drugs
•where the penetration of the menstruum into the
cellular tissues is very slow and
•the solute is not readily soluble into the solvent and
•the quantity of the menstruum is very less.
In such cases Soxhlet extractor is used where small volume of hot menstruum is
passed over the drug time and again to dissolve out the active constituents until
the drug is exhausted. The process is known as Soxhlation.
Apparatus:
i)A round bottom flask in which the menstruum is boiled.
ii)An extraction chamber in which drug is filled, is fitted with side tube and a
siphon.
iii)A reflux condenser.
The size of the drug is reduced.
The drug is packed in a ‘thimble’ made of filter paper which is then placed into
the wider part of the extractor.
[N.B. thimble is used to prevent choking of the lower part of the extractor.]
18. 18
Menstruum is placed in the flask and boiled. The vapor rises through the side
tube to the condenser, where the vapor is condensed and fall on the packed
drug, through which it percolates and extract out the active constituents.
As the volume of menstruum in the extractor increases, the level of liquid in the
siphon also increases till it reaches the maximum point from where it is siphoned
out into the flask.
On further heating the menstruum vaporizes while the dissolved active
constituents remain behind in the flask. The alternate filling and emptying of the
body of the extractor goes on continuously till the drug is exhausted. Thus the
same quantity of menstruum is made to percolate repeatedly, about 14 to 15
times through the drug and the active constituents are collected in the flask.
Merits/Demerits
Despite the economic advantages of solvent extraction, the use of volatile
organic solvents such as hexane, acetone and methanol for processing medicinal
plants has been limited due to environmental considerations. Hot continuous
extraction technology shall always remain the method of choice for high
efficiency, economical extraction and with less capital investment.
Advantages: Disadvantages:
1. The displacement of
transfer equilibrium by
repeatedly bringing fresh
solvent into contact with the
solid matrix.
2. Maintaining a relatively
high extraction temperature
with heat from the distillation
fl ask.
1. Agitation is not possible in the Soxhlet
device.
2. The possibility of thermal decomposition
of the target compounds cannot be ignored
as the extraction usually occurs at the
boiling point of the solvent for a long time.
Chemical constituents of the drug: The
process is unsuitable for thermolabile active
constituents, e.g. enzymes, alkaloids,
anthraquinone derivatives, esters etc
3.Physical character of the drug: If the
physical character of the drug is such that it
would block the Soxhlet apparatus then this
method is not suitable. e.g opium, gum,
resin, orange peel etc.
4.Solvent: Only pure solvents or constant
boiling mixtures (like alcohol-water) can be
used for this purpose.
19. 19
Qn No.
in Exam
paper
Expected Answer Marks
3.2 Explain the construction, operation, advantages, disadvantages and applications
of hammer mills. List factors affecting choice of size reduction equipment.
[P8A:28-29] [P8A: 37-38, 16-17].
HAMMER MILL
Method of size reduction: Impact
Construction and working :
Hammer mill consists of a stout
metal casing, enclosing a central
shaft to which four or more
hammers are attached. These are
mounted with swivel joints, so
that the hammers swing out to a
radial position when the shaft is
rotated. The lower part of the
casing consists of screen through
which materials can escape,
when sufficiently size reduced.
The material is collected in a
container placed below the
screen.
The screen can be changed according to the particle size required.
According to the purpose of operation the hammers may be square-faced,
tapered to a cutting form or have a stepped-form.
The interior of the casing may be undulating in shape, instead of smooth
circular form for better impact.
The rotor operates at a speed of 80cycles per second.
Advantages:
(a) It is rapid in action, and is capable of grinding many different types of materials.
(b) The product can be controlled by variation of rotor speed, hammer type and size and
shape of mesh. (c) Operation is continuous. (d) No surface moves against each other so
very little problem of contamination of mill materials.
Disadvantages:
(a) High speed of operation generates heat that may affect thermolabile materials
or drugs containing gum, fat or resin.
(b) The rate of feed should be controlled otherwise the mill may be choked.
(c) Because of high speed of operation, the hammer mill may be damaged if
some foreign materials like stone, metal pieces etc. are present in the feed.
Applications: Powdering of crystals and filter cakes.
8
20. 20
Factors influencing choice of Size Reduction machinery
1. Nature of the raw material: Drugs must be thoroughly dried before they are
subjected to size reduction. Drugs like belladonna, gentian, liquorice and squill
are returned to the drying rooms to the drying rooms after they have been
partially comminuted, as they rapidly absorb absorb moisture from the
atmosphere and as the moisture may not be removed from all parts of the drug
during the initial drying stage. In the case of water insoluble substances, wet
grinding of the material can be done. For the preparation of aqueous dispersions
of drugs this method is very effective since deflocculating agents may be
included to prevent agglomeration of the particles.
Substances that are hygroscopic or volatile or very poisonous or that need-
prolonged trituration are more easily prepared in closed porcelain ball mills.
Fibrous material seed tearing apart of the fibres and this can be achieved in high-
speed impact mills. Substances of a resinous or oily nature shall not be subjected
to heavy pressures or much heat as a pasty mass may result. Hence, a ball mill
will not be suitable and they are better grounded in a micronizer or a hammer
mill. The replacement of air by an inert gas is necessary when grinding readily
oxidizable materials and ball mills and high-speed impact mills are generally
used in this way.
2. Nature of the product: A powdered drug produced in a ball mill differs from
the product in a micronizer or a disintegrator even though both powders may be
screened to the same fineness. Differences exist in the shape of the particles, their
toughness and their internal pore structure. Powder obtained from grinding
mills like ball mill is more compact and less porous than that obtained in high
speed impact mills like a disintegrator. For the grinding of a sterile material
under aseptic conditions, a mill is required that can be easily sterilized and
sealed to prevent contamination during the grinding operation. A batch
operation porcelain ball mill is most suitable for this purpose. When iron and
copper contamination of pharmaceutical products is to be avoided stainless steel
or ceramic material may be used for the surfaces of a mill coming into contact
with the drug.
3. Degree of comminution required: The degree of comminution of materials
varies according to the purpose for which they are required. For the preparation
of galenicals, the size of the vegetable drug powder employed for extraction
varies from coarse to fine powder. Tincture preparation requires bruised to
moderately coarse powders. For percolation, drug powders should not contain a
large proportions of fines to avoid uneven extraction. Coarse to moderately
coarse powder, with a minimum of fine powder, are all most easily obtained by
using high speed mills of the impact type. Materials such as cascara, liquorice,
belladonna leaf and root and ginger are all easily broken down in such mills. The
grindability of different grades of a vegetable drug usually varies and during
comminution the softer portions get size reduced first. Therefore it is sometimes
21. 21
useful to screen out the powdered drug and return the coarser material to the
mill for further size reduction. This prevents continued milling of the softer
portions resulting in formation of too much fines. The same principle is also
applicable to crystalline drugs although they are of uniform composition. The
rate of absorption of sparingly soluble drugs, either through the Gastro-
intestinal tract or when administered parenterally, depends on particle size.
Penicillin in a medium of aluminium monostearte and arachis oil appears to be
most effective when 90 % of the particles are smaller than 5 micrometers. The
relatively insoluble sulphonamides attain their maximum antibacterial activity at
crystal sizes of about 1 micrometer or below. For insufflations the drug should
be smaller than about 5 micrometers.
22. 22
Qn No.
in Exam
paper
Expected Answer Marks
3.3 Classify pharmaceutical additives. Comment on the relation between their
purity and their quality with examples and on any safety concerns. List the ideal
properties of pharmaceutical additives.[P6:6-7, 9-10,36 9,11-14,21] . [P6:1-4,
23,36, 5]
A pharmaceutical additive/excipient is defined as any substance (natural,
semisynthetic or synthetic) other than the active drug or prodrug that is
included in the manufacturing process or is contained in a finished
pharmaceutical dosage form.
Classification of additives from regulatory point of view
• First category (approved excipients) : compounds originating from the
food industry (generally recognised as safe or that have been present in
use for a very long time
• Intermediate category (essentially new excipients): compounds obtained
by means of the structural modification of the excipients already
approved or those already used in the food or cosmetic industries.
• Third category : new compounds, never previously used in the
pharmaceutical field and it is growing rapidly due to the present interest
in modified-release formulations and the requirements of the modern
high-productivity compressing/ tabletting machines.
Classification of additives based on origin
• animal (e.g. lactose, gelatin, stearic acid),
• plant (e.g. starches, sugars, cellulose, arginates),
• mineral (e.g. calcium phosphate, silica) and
• synthesis (e.g. PEGs, polysorbates, povidone, etc.)
Pharmaceutical additives must be submitted to more thorough-going
analytical controls guarantee the quality required by the pharmaceutical
industry
Impurities to be kept at an acceptable minimum level esp if they are toxic.
But at times their presence is functionally necessary eg (hemicellulose in
micro-crystalline cellulose.)
“Pure” Excipients that don’t work include
Pure DiCalcium Phosphate doesn’t compact well due to absence of impurity
related crystal defects.
Pure Magnesium Stearate doesn’t lubricate due to absence of water (only
hydrates lubricate)
8
23. 23
Ideal properties of excipients. The ideal excipient should be
1. Nontoxic, Chemically inert (nonreactive with the drug and other
excipients) & Physiologically inert (inert in the human body).
2. Physically & Chemically stable both by itself and in combination with the
drug.
3. Free of unacceptable microbes & does not support mould growth.
4. Colour compatible and maintains the uniformity of shades.(have pleasing
organoleptic properties)
5. Have no deleterious effect on the bioavailability of active drug.
6. able to fill numerous and important functions.
7. Should perform, ie fulfill its inherent function
8. have low equipment and process sensitivity,
9. be well characterized and well accepted by the industry and regulatory
agencies.
A limited choice of excipients with all of these attributes makes formulation
design and excipient selection challenging.
24. 24
Qn No.
in Exam
paper
Expected Answer Marks
3.4 Describe the evolution of pharmaceutics in the twentieth century listing any 2
technological breakthroughs. Enumerate the functions (duties) of the hospital
and community pharmacist.
[P3:1-5] [P2A: 25-27, 30-34, 12-16, P2B:1-5]
• The essence of pharmaceutics is the amalgamation of physical science
(physical pharmacy) with aspects of biological science.
• At its center is not only the dosage form with its active and inactive
ingredients but also the behavior of the ensemble in the environment in
which these medicines are used, generally in human subjects.
• From the early days of the 20th century to the mid-1950s, it was
concerned primarily with the science and practice of the manufacture of
medicines (dosage forms) on small and large scales and the preparation of
galenicals.
• Pharmaceutics has progressed as drugs have developed first from natural
product extracts, through synthetic and generally small molecules to
peptides, proteins, and oligonucleotides and DNA itself, into the
beginning era of cell-based therapies.
• Initially not much regard was given to the fate of the dosage form in vivo.
• However, technological break-through led to counter the liabilities of the
inherent drug. E.g.
• 1. Enteric coating of tablets to minimize drug’s irritant effect on the
intestinal mucosa, to minimise degradation of drug by acidic pH.
• 2. The first commercial sustained-release preparations emerged in the late
1940s with the SpansuleTM, which contained wax-coated beads with
different release properties in a soluble capsule, thus controlling release of
the drug in the GI tract.
The day to day duties of a pharmacist varies from one setup to another.
Community pharmacist
– Provide drug information to other healthcare professionals
– Provide patient care by identifying disease, educating patient on disease,
precautions, life style changes, etc
– Runs a business, supervise staff, maintain inventory
– Gather patient information, screen, monitor and advice for self-treatment
with over-the-counter (OTC) products sold without a prescription.
– Prepare doses of Precompounded medication, Extemporaneously
compounded nonsterile medications
8
25. 25
– Dispensing, recordkeeping, and pricing
– receiving a verbal, or oral, prescription in person or by telephone
– preparing the written form of the verbal prescription
– interpreting and evaluating prescriptions
– reviewing patient profile & screen for (e.g., medication history,
duplication of medications, drug interactions, Drug-disease
contraindication, Incorrect dosage or duration of treatment, Drug-
allergy interactions, Clinical abuse/misuse)
– review and discuss with the patient the following
• name and description of medication
• dosage form
• dose
• route of administration
• duration of drug therapy
• action to take after a missed dose
• common severe side effects or adverse effects
• interactions and therapeutic contraindications, ways to prevent
the same, and actions to be taken if they occur
• methods for self-monitoring of the drug therapy
• prescription refill information
• proper storage of the drug
• special directions and precautions for preparation,
administration, and use by the patient
Hospital pharmacist
– Dispenses oral medications
– Prepares and dispenses parenteral medications and doses of
Extemporaneously Compounded Sterile Medications
– Sometimes specializes, with advanced training in an area of patient care
– Educates and counsels patients
– Provides drug information
– Supervise replenishing and transport of controlled drugs for floor stock
– Administers a department by
– developing policies and procedures
– purchasing drugs and supplies
– monitoring drug use in the hospital
26. 26
Qn No.
in Exam
paper
Expected Answer Marks
3.5 List the various methods of heating and comment on steam’s benefits and
problems. Using a phase diagram, explain lyophilisation and benefits of freeze
drying.[P11:5-11] [P11:45-47 P11~lyoph.pdf:2-5]
various methods of heating include
• By burning fuels (coal, petroleum, natural gas)
• By Electric heating elements(high resistance)- cheap, clean, rapid
response, easy handling
• Direct heating- material in direct contact with heat (high temperature
achieved, but material must be thermostable)
• Indirect heating- material in contact with a medium or bath, inturn in
contact with heat (controlled temperature achieved) water bath, steam
bath, paraffin-oil bath,
In pharmaceutical processes at anything other than laboratory scale, the most
commonly used heating medium is steam. Steam is also very important as a
sterilizing medium. The reasons for the widespread use of steam include:
• The raw material (water) is cheap and plentiful.
• It is easy to generate, distribute and control.
• It is generally cheaper than viable alternative forms of heating, e.g. electricity.
• It is clean, odourless and tasteless, and accidental contamination of the product
is less likely to be
serious.
• It has a high heat content (in the form of latent heat) and can heat materials
very quickly.
• The heat is given up at a constant temperature, which is useful in controlling
heating processes and in sterilization.
One disadvantage of the use of steam is that it is used at pressures that are
typically two to three times
higher than atmospheric, and thus steam presents potential safety problems and
necessitates the use of
high-strength piping. To appreciate why steam is used in pharmaceutical
processing and the principles of heat transfer using steam it is necessary to
consider how the steam is produced, its heat content, and how the heat content
varies with pressure and temperature.
• The temperature at which water boils depends on the pressure exerted on the
water surface. This is utilized in sterilization processes, where adjustment of the
pressure allows selection of the temperature at which steam condenses and
therefore the temperature at which the articles to be sterilized are exposed.
Similarly, in heat transfer processes, the desired temperature gradient can be
8
27. achieved by adjusting the steam pressure.
• Problems with Steam contaminated by air
Air is a bad heat conductor and thus reduces heat transfer, increase heating time
and cost. From dalton’s law,
Total Pressure= Partial Pressure(air)+Partial Pressure(steam).
Thus lower pressure means lower steam temperature, lower heat gradient,
higher heating time, possibly poor sterilization.
Freeze drying or lyophilization
• The solution is frozen prior to drying and the solvent is then sublimed
(that is, converted to the gas phase directly from the solid phase), below the
melting point of the solvent.
• Freeze drying is often carried
out under reduced pressure (using a
vacuum pump) to allow drying to
proceed at a reasonable rate.
• This process avoids collapse
of the solid structure, leading to a
low-density, highly porous product
that can quickly reabsorb the solvent
when needed (lyophile means ‘‘likes
the solvent “)
• This method was first used
industrially to produce dehydrated
vaccines, and to bring dehydrated
blood to assist war casualties. It is
regarded as the best method for
preserving the quality and biological
activity of proteins, vitamins, and other bioactive compounds.
• In a typical phase diagram, the boundary between gas and liquid runs
from the triple point to the critical point. Regular drying is shown by the green
arrow; freeze drying, by the blue arrow.
27
by adjusting the steam pressure.
• Problems with Steam contaminated by air
Air is a bad heat conductor and thus reduces heat transfer, increase heating time
From dalton’s law,
Total Pressure= Partial Pressure(air)+Partial Pressure(steam).
Thus lower pressure means lower steam temperature, lower heat gradient,
possibly poor sterilization.
Freeze drying or lyophilization
The solution is frozen prior to drying and the solvent is then sublimed
e gas phase directly from the solid phase), below the
melting point of the solvent.
Freeze drying is often carried
out under reduced pressure (using a
vacuum pump) to allow drying to
proceed at a reasonable rate.
This process avoids collapse
structure, leading to a
density, highly porous product
that can quickly reabsorb the solvent
when needed (lyophile means ‘‘likes
This method was first used
industrially to produce dehydrated
vaccines, and to bring dehydrated
ssist war casualties. It is
regarded as the best method for
preserving the quality and biological
activity of proteins, vitamins, and other bioactive compounds.
In a typical phase diagram, the boundary between gas and liquid runs
the critical point. Regular drying is shown by the green
, by the blue arrow.
Air is a bad heat conductor and thus reduces heat transfer, increase heating time
Thus lower pressure means lower steam temperature, lower heat gradient,
The solution is frozen prior to drying and the solvent is then sublimed
e gas phase directly from the solid phase), below the
In a typical phase diagram, the boundary between gas and liquid runs
the critical point. Regular drying is shown by the green
28. 28
Lyophilization is a process which extracts the water from foods and other
products so that the foods or products remain stable and are easier to store
at room temperature (ambiant air temperature).
Lyophilization is carried out using a simple principle of physics called
sublimation. Sublimation is the transition of a substance from the solid to the
vapour state, without first passing through an intermediate liquid phase. To
extract water from foods, the process of lyophilization consists of:
1. Freezing the food so that the water in the food become ice;
2. Under a vacuum, sublimating the ice directly into water vapour;
3. Drawing off the water vapour;
4. Once the ice is sublimated, the foods are freeze-dried and can be
removed from the machine.
Lyophilization has many advantages compared to other drying and preserving
techniques.
1. Lyophilization maintains food/ biochemical and chemical reagent
quality because they remains at a temperature that is below
the freezing-point during the process of sublimation; The use of
lyophilization is particularly important when processing lactic bacteria,
because these products are easily affected by heat.
2. Food/biochemicals and chemical reagents which are lyophilized can
usually be stored without refrigeration, which results in a significant
reduction of storage and transportation costs.
3. Lyophilization greatly reduces weight, and this makes the products
easier to transport. For example, many foods contain as much as 90%
water. These foods are 10 times lighter after lyophilization.
4. Because they are porous, most freeze-dried products can be easily
rehydrated. Lyophilization does not significantly reduce volume,
therefore water quickly regains its place in the molecular structure of
the food/ biochemicals and chemical reagents.