The document discusses dissolution modeling and its importance in predicting drug release kinetics. It describes 10 common dissolution models including diffusion layer, Danckwert's, interfacial barrier, zero-order, first-order, Higuchi, Korsmeyer-Peppas, Hixson-Crowell, Baker-Lonsdale, and Weibull models. Each model has a unique equation to characterize drug release based on factors like solubility, surface area, diffusion coefficients and particle size. Understanding these models helps optimize formulations and develop in vitro-in vivo correlations to reduce bioequivalence studies.
The document discusses factors to consider for scaling up tablet manufacturing from the laboratory to a pilot plant or production scale. It outlines key stages in tablet production including material handling, dry mixing, granulation, drying, sizing, blending, compression, and coating. For each stage, it identifies parameters that must be established during scale up such as equipment type, processing rates, temperatures, and quality control tests. Maintaining consistency while increasing batch sizes is important for ensuring reproducible, high quality tablets at larger scales.
DIffusion, Dissolution and Pharmacokinetic Parameters.pptxKailas Mali
This document discusses various parameters used to study drug release and dissolution from pharmaceutical dosage forms, including diffusion parameters, dissolution parameters, pharmacokinetic parameters, and models like Higuchi and Peppas plots. It defines key terms like diffusion, flux, Fick's first law, and discusses how factors like agitation, pH, surfactants, viscosity, and temperature can influence dissolution. Key drug release mechanisms and models are also summarized.
This document discusses chronopharmacokinetics and circadian rhythms. It begins by explaining that drug absorption, distribution, metabolism and elimination can vary based on the time of day due to physiological rhythms. It then defines chronopharmacokinetics as studying how drug plasma levels vary based on the time of administration. Key factors that can cause time-dependent variations, like changes in GI function, enzyme activity and organ blood flow, are summarized. Examples are given of disease symptoms and drug effects that vary over 24-hour periods. Finally, applications of chronotherapeutic drug delivery systems are briefly mentioned to maximize drug effects at specific times.
This document discusses chemical kinetics and the order of chemical reactions. It defines chemical kinetics as the study of the rate of chemical processes and changes. The order of a reaction determines how the concentration of reactants influences the reaction rate. Zero-order reactions have rates independent of concentration. First-order reactions have rates directly proportional to concentration. Second-order reactions have rates proportional to the square of a reactant's concentration. The document also outlines methods for determining reaction order, such as using integrated rate equations and half-life calculations.
Facility Requirements to Initiate the GLP Studyvishnu Jatoth
The document outlines the facility requirements for conducting a GLP study using animals. Key requirements include:
1) The animal research facility must carefully control environmental parameters like temperature, humidity, and light to minimize effects on animals and prevent contact between animals of different studies or with unintended test items.
2) Experimental rooms must be individually ventilated with strict separation of clean and dirty areas, and maintain standards for lighting, noise, and air exchanges.
3) The facility must have provisions for quarantine, housing, feeding, watering, bedding, caging, necropsy, storage, and documentation in accordance with species-specific standards.
4) Detailed standard operating procedures must be maintained and
The document discusses key considerations for designing diffusion cell experiments, including choosing between static and continuous flow diffusion cells, selecting an appropriate membrane type, preparing donor formulations, choosing a receptor medium, and developing a sampling method. It emphasizes the importance of having a well-planned experimental protocol to reduce failed attempts and ensure consistency between experiments.
This document discusses dissolution controlled and diffusion controlled drug delivery systems. It describes some key challenges with traditional drug delivery like short half-life, metabolism, and solubility issues that newer systems aim to address. Dissolution controlled systems control drug release through encapsulation or matrix devices as the polymer dissolves. Diffusion controlled systems use reservoir or matrix devices where the drug diffuses through a membrane at a controlled rate determined by properties like thickness. Both approaches can provide more consistent drug levels compared to traditional methods.
The document discusses dissolution modeling and its importance in predicting drug release kinetics. It describes 10 common dissolution models including diffusion layer, Danckwert's, interfacial barrier, zero-order, first-order, Higuchi, Korsmeyer-Peppas, Hixson-Crowell, Baker-Lonsdale, and Weibull models. Each model has a unique equation to characterize drug release based on factors like solubility, surface area, diffusion coefficients and particle size. Understanding these models helps optimize formulations and develop in vitro-in vivo correlations to reduce bioequivalence studies.
The document discusses factors to consider for scaling up tablet manufacturing from the laboratory to a pilot plant or production scale. It outlines key stages in tablet production including material handling, dry mixing, granulation, drying, sizing, blending, compression, and coating. For each stage, it identifies parameters that must be established during scale up such as equipment type, processing rates, temperatures, and quality control tests. Maintaining consistency while increasing batch sizes is important for ensuring reproducible, high quality tablets at larger scales.
DIffusion, Dissolution and Pharmacokinetic Parameters.pptxKailas Mali
This document discusses various parameters used to study drug release and dissolution from pharmaceutical dosage forms, including diffusion parameters, dissolution parameters, pharmacokinetic parameters, and models like Higuchi and Peppas plots. It defines key terms like diffusion, flux, Fick's first law, and discusses how factors like agitation, pH, surfactants, viscosity, and temperature can influence dissolution. Key drug release mechanisms and models are also summarized.
This document discusses chronopharmacokinetics and circadian rhythms. It begins by explaining that drug absorption, distribution, metabolism and elimination can vary based on the time of day due to physiological rhythms. It then defines chronopharmacokinetics as studying how drug plasma levels vary based on the time of administration. Key factors that can cause time-dependent variations, like changes in GI function, enzyme activity and organ blood flow, are summarized. Examples are given of disease symptoms and drug effects that vary over 24-hour periods. Finally, applications of chronotherapeutic drug delivery systems are briefly mentioned to maximize drug effects at specific times.
This document discusses chemical kinetics and the order of chemical reactions. It defines chemical kinetics as the study of the rate of chemical processes and changes. The order of a reaction determines how the concentration of reactants influences the reaction rate. Zero-order reactions have rates independent of concentration. First-order reactions have rates directly proportional to concentration. Second-order reactions have rates proportional to the square of a reactant's concentration. The document also outlines methods for determining reaction order, such as using integrated rate equations and half-life calculations.
Facility Requirements to Initiate the GLP Studyvishnu Jatoth
The document outlines the facility requirements for conducting a GLP study using animals. Key requirements include:
1) The animal research facility must carefully control environmental parameters like temperature, humidity, and light to minimize effects on animals and prevent contact between animals of different studies or with unintended test items.
2) Experimental rooms must be individually ventilated with strict separation of clean and dirty areas, and maintain standards for lighting, noise, and air exchanges.
3) The facility must have provisions for quarantine, housing, feeding, watering, bedding, caging, necropsy, storage, and documentation in accordance with species-specific standards.
4) Detailed standard operating procedures must be maintained and
The document discusses key considerations for designing diffusion cell experiments, including choosing between static and continuous flow diffusion cells, selecting an appropriate membrane type, preparing donor formulations, choosing a receptor medium, and developing a sampling method. It emphasizes the importance of having a well-planned experimental protocol to reduce failed attempts and ensure consistency between experiments.
This document discusses dissolution controlled and diffusion controlled drug delivery systems. It describes some key challenges with traditional drug delivery like short half-life, metabolism, and solubility issues that newer systems aim to address. Dissolution controlled systems control drug release through encapsulation or matrix devices as the polymer dissolves. Diffusion controlled systems use reservoir or matrix devices where the drug diffuses through a membrane at a controlled rate determined by properties like thickness. Both approaches can provide more consistent drug levels compared to traditional methods.
Optimization technique is a rational approach for selecting the excipients, their concentrations and process conditions for obtaining the best possible product satisfying the quality characteristics.
Optimization is an act, process or methodology of making design, system or decisions as fully perfect, functional or as effective as possible.
Technology Transfer From R and D to Pilot Plant to Plant for Non-Sterile Semi...shiv
Technology transfer is important for successful progress of drug development from research to commercialization. This presentation discusses technology transfer from research and development to pilot plant and full-scale production of non-sterile semisolids. It covers the importance of pilot plants in scale-up, factors to consider in scaling up semisolids like mixing equipment and homogenization processes. SUPAC guidelines for scale-up and post-approval changes are also summarized. A case study demonstrates issues encountered like congealing during scale-up of a cream formulation containing diethylene glycol monoethyl ether from lab to pilot scale.
Process validation of tablet compressionSanket Shinde
This document provides an overview of tablet compression machine validation. It begins with introducing the need and types of process validation. Then it discusses validation of tablet compression machines in particular, including the critical parameters to monitor and qualify like compression force, speed, and in-process testing. It outlines the validation protocols for installation, operational, and performance qualifications. The document emphasizes the importance of revalidating if any changes are made to equipment, location, parts, or normal schedules.
Solid state stability and shelf-life assignment, Stability protocols,reports ...Durga Bhavani
This document discusses guidelines for solid state stability and shelf-life assignment studies as outlined by ICH. It provides definitions of stability, the need for stability studies, and factors that influence drug degradation like temperature, moisture, light and interactions. The document outlines the types of studies, including real-time and accelerated stability studies. It discusses stability protocols, reports, and test conditions recommended by ICH to determine a drug's shelf life.
Drug transporters play an important role in drug absorption, distribution, metabolism, and excretion. They are located in organs like the intestine, liver, and kidney and can influence the pharmacokinetics and pharmacodynamics of drugs through drug-drug interactions. Transporters can be either uptake transporters that move drugs into cells or efflux transporters that move drugs out of cells. Inhibition or induction of these transporters by coadministered drugs can increase or decrease the intracellular concentrations of victim drugs, altering their effects. This is an important consideration for drug interactions.
In 3 sentences:
This document discusses different methods for determining drug absorption - in vitro, in vivo, and in situ. In vitro methods determine permeability outside the body using tissues. In vivo methods are conducted inside the body by measuring drug levels in blood/urine. In situ methods simulate in vivo conditions by perfusing intestinal segments to determine drug diffusion rates.
selection of dissolution medium And dissolution study of solid dosage formAshwin Patil
The document discusses dissolution testing of solid oral dosage forms. It covers selection of dissolution media based on factors like drug solubility and formulation type. Common dissolution media include simulated gastric fluid, water and simulated intestinal fluid. Selection of parameters like rpm, time and apparatus depends on the formulation. Dissolution testing is important for quality control and bioequivalence studies. It provides insight into in vivo performance and helps product development.
1. Dissolution is the process by which a solid substance dissolves in a solvent to form a solution. The rate of dissolution depends on factors like temperature, solvent composition, and the liquid/solid interface area.
2. There are several theories that describe the drug dissolution process, including the diffusion layer model, penetration or surface renewal theory, and interfacial barrier model. The most common model is the diffusion layer model, which involves the formation of a saturated film at the solid/liquid interface and diffusion of the drug through this layer.
3. Key factors that affect drug dissolution include the solubility and permeability of the drug substance, the pH and volume of the dissolution medium, and the design of
This document discusses different coating methods and techniques used in the pharmaceutical industry. It describes:
1) Rotating coating pans and fluidized bed coaters are commonly used to coat tablets by spraying coating solutions and evaporating the liquid. Traditional techniques include sugar coating and film coating.
2) Key steps in sugar coating include sealing, sub coating, smoothing/syrup coating and finishing. Film coating uses similar equipment and parameters as sugar coating.
3) Common coating equipment includes standard coating pans, perforated coating pans, and fluidized bed coaters. Top spray, bottom spray, and tangential spray are fluidized bed coating methods that differ in how the coating solution is applied.
4) Dry particle
This document discusses alternative non-official methods for measuring drug dissolution that do not require a sink condition. It describes natural convection non-sink methods including the Klein solvmeter, Nelson hanging pellet, and Levy static disk methods. Forced convection non-sink methods are also covered, such as the tumbling, beaker, and rotating disk methods. Each method is explained in one to two sentences, outlining how the drug dosage form is placed in the dissolution medium and how samples are collected and analyzed over time to determine the dissolution rate.
The document discusses the effect of various parameters on drug dissolution. It describes how agitation, pH, viscosity, temperature and other properties of the dissolution medium influence the dissolution rate. The amount of dissolution medium and maintenance of sink conditions are also important. Various dissolution models like Hixson-Crowell are presented.
This document discusses various compendial methods for drug dissolution testing. It begins by defining dissolution as the process where a solid substance solubilizes in a solvent, transferring mass from the solid surface to the liquid phase. It then describes the seven USP dissolution apparatus types and their applications for testing different drug products like tablets, capsules, modified release formulations and transdermal systems. The document provides details on factors that influence dissolution test design and the principles of operation for each apparatus type.
This document provides an overview of 11 mathematical models that are commonly used to study drug release from pharmaceutical drug delivery systems: 1) Diffusion Model, 2) Zero Order Kinetics Model, 3) First Order Kinetics Model, 4) Higuchi Model, 5) Korsmeyer–Peppas Model, 6) Hixson–Crowell Model, 7) Weibull Model, 8) Baker–Lonsdale Model, 9) Hopfenberg Model, 10) Gompertz model, and 11) Sequential Layer Model. Each model is described in terms of the equations used and their typical applications. The models can help understand drug release mechanisms and optimize drug delivery system design and performance.
This document provides information about small volume parenterals (SVPs). It defines SVPs as injections packaged in containers of 100ml or less. SVPs can include pharmaceutical products, biological products, and more. They are commonly classified as single dose ampoules, single dose vials, multiple dose vials, and prefilled syringes. The document discusses vehicles, additives, processing, and more regarding the formulation and manufacturing of SVPs.
This document discusses drug dissolution, including definitions, theories, mechanisms, factors affecting dissolution, intrinsic dissolution rate, and in-vitro dissolution testing models. It defines dissolution as the mass transfer of a solid substance into a liquid solvent. The key theories discussed are the diffusion layer model, Danckwert's penetration model, and the interfacial barrier model. Factors affecting dissolution include properties of the drug, test conditions, and dosage form characteristics. Common in-vitro dissolution testing models described are non-sink and sink methods that utilize natural or forced convection with varying degrees of agitation.
CO–PROCESSED EXCIPIENTS FOR TABLETS.pdfYamini Shah
Purpose of the present review is to provide an in depth knowledge on recent developments in excipients preparation, technology and approaches involved in their formation and development. Excipients play an important role in dosage form development. In conventional formulation of dosage forms, each excipient is used to provide its required function/performance. Presently, excipient manufacturers have focused their attention on producing a multifunctional excipients with improvement in their performance and quality of dosage form. Manipulation in the functionality of excipient is provided by the co-processing of two or more existing excipients.
Microcapsules: types, preparation and evaluationMOHAMMAD ASIM
This document discusses microcapsules, including their definition, reasons for microencapsulation, types of microcapsules, formulation considerations, preparation techniques, evaluation methods, and applications in pharmacy. Microencapsulation involves enclosing a substance inside a miniature capsule and can be used to increase stability, control release rates, mask tastes/odors, and more. Common preparation techniques include solvent evaporation, spray drying, pan coating, and coacervation. Microcapsules find applications such as taste masking, sustained release, separating incompatibilities, and more in the pharmaceutical industry.
Modeling and comparison of dissolution profiles - Review by Paulo Costa*, Jos...MAHENDRA PRATAP SWAIN
Over recent years, drug release / dissolution from solid pharmaceutical dosage forms has been the subject of intense and profitable scientific developments. Whenever a new solid dosage form is developed or produced, it is necessary to ensure that drug dissolution occurs in an appropriate manner. The pharmaceutical industry and the registration authorities do focus, nowadays, on drug dissolution studies. The quantitative analysis of the values obtained in dissolution / release tests is easier when mathematical formulas that express the dissolution results as a function of some of the dosage forms characteristics are used. In some cases, these mathematics models are derived from the theoretical analysis of the occurring process. In most of the cases the theoretical concept does not exist and some empirical equations have proved to be more appropriate. Drug dissolution from solid dosage forms has been described by kinetic models in which the dissolved amount of drug is a function of the test time. Some analytical definitions of function are commonly used, such as zero order, first order, Hixson–Crowell,Weibull, Higuchi, Baker–Lonsdale, Korsmeyer–Peppas and Hopfenberg models. Other release parameters, such as dissolution time, assay time, dissolution efficacy, difference factor (f1), similarity factor (f2) and Rescigno index can be used to characterize drug dissolution / release profiles.
Optimization technique is a rational approach for selecting the excipients, their concentrations and process conditions for obtaining the best possible product satisfying the quality characteristics.
Optimization is an act, process or methodology of making design, system or decisions as fully perfect, functional or as effective as possible.
Technology Transfer From R and D to Pilot Plant to Plant for Non-Sterile Semi...shiv
Technology transfer is important for successful progress of drug development from research to commercialization. This presentation discusses technology transfer from research and development to pilot plant and full-scale production of non-sterile semisolids. It covers the importance of pilot plants in scale-up, factors to consider in scaling up semisolids like mixing equipment and homogenization processes. SUPAC guidelines for scale-up and post-approval changes are also summarized. A case study demonstrates issues encountered like congealing during scale-up of a cream formulation containing diethylene glycol monoethyl ether from lab to pilot scale.
Process validation of tablet compressionSanket Shinde
This document provides an overview of tablet compression machine validation. It begins with introducing the need and types of process validation. Then it discusses validation of tablet compression machines in particular, including the critical parameters to monitor and qualify like compression force, speed, and in-process testing. It outlines the validation protocols for installation, operational, and performance qualifications. The document emphasizes the importance of revalidating if any changes are made to equipment, location, parts, or normal schedules.
Solid state stability and shelf-life assignment, Stability protocols,reports ...Durga Bhavani
This document discusses guidelines for solid state stability and shelf-life assignment studies as outlined by ICH. It provides definitions of stability, the need for stability studies, and factors that influence drug degradation like temperature, moisture, light and interactions. The document outlines the types of studies, including real-time and accelerated stability studies. It discusses stability protocols, reports, and test conditions recommended by ICH to determine a drug's shelf life.
Drug transporters play an important role in drug absorption, distribution, metabolism, and excretion. They are located in organs like the intestine, liver, and kidney and can influence the pharmacokinetics and pharmacodynamics of drugs through drug-drug interactions. Transporters can be either uptake transporters that move drugs into cells or efflux transporters that move drugs out of cells. Inhibition or induction of these transporters by coadministered drugs can increase or decrease the intracellular concentrations of victim drugs, altering their effects. This is an important consideration for drug interactions.
In 3 sentences:
This document discusses different methods for determining drug absorption - in vitro, in vivo, and in situ. In vitro methods determine permeability outside the body using tissues. In vivo methods are conducted inside the body by measuring drug levels in blood/urine. In situ methods simulate in vivo conditions by perfusing intestinal segments to determine drug diffusion rates.
selection of dissolution medium And dissolution study of solid dosage formAshwin Patil
The document discusses dissolution testing of solid oral dosage forms. It covers selection of dissolution media based on factors like drug solubility and formulation type. Common dissolution media include simulated gastric fluid, water and simulated intestinal fluid. Selection of parameters like rpm, time and apparatus depends on the formulation. Dissolution testing is important for quality control and bioequivalence studies. It provides insight into in vivo performance and helps product development.
1. Dissolution is the process by which a solid substance dissolves in a solvent to form a solution. The rate of dissolution depends on factors like temperature, solvent composition, and the liquid/solid interface area.
2. There are several theories that describe the drug dissolution process, including the diffusion layer model, penetration or surface renewal theory, and interfacial barrier model. The most common model is the diffusion layer model, which involves the formation of a saturated film at the solid/liquid interface and diffusion of the drug through this layer.
3. Key factors that affect drug dissolution include the solubility and permeability of the drug substance, the pH and volume of the dissolution medium, and the design of
This document discusses different coating methods and techniques used in the pharmaceutical industry. It describes:
1) Rotating coating pans and fluidized bed coaters are commonly used to coat tablets by spraying coating solutions and evaporating the liquid. Traditional techniques include sugar coating and film coating.
2) Key steps in sugar coating include sealing, sub coating, smoothing/syrup coating and finishing. Film coating uses similar equipment and parameters as sugar coating.
3) Common coating equipment includes standard coating pans, perforated coating pans, and fluidized bed coaters. Top spray, bottom spray, and tangential spray are fluidized bed coating methods that differ in how the coating solution is applied.
4) Dry particle
This document discusses alternative non-official methods for measuring drug dissolution that do not require a sink condition. It describes natural convection non-sink methods including the Klein solvmeter, Nelson hanging pellet, and Levy static disk methods. Forced convection non-sink methods are also covered, such as the tumbling, beaker, and rotating disk methods. Each method is explained in one to two sentences, outlining how the drug dosage form is placed in the dissolution medium and how samples are collected and analyzed over time to determine the dissolution rate.
The document discusses the effect of various parameters on drug dissolution. It describes how agitation, pH, viscosity, temperature and other properties of the dissolution medium influence the dissolution rate. The amount of dissolution medium and maintenance of sink conditions are also important. Various dissolution models like Hixson-Crowell are presented.
This document discusses various compendial methods for drug dissolution testing. It begins by defining dissolution as the process where a solid substance solubilizes in a solvent, transferring mass from the solid surface to the liquid phase. It then describes the seven USP dissolution apparatus types and their applications for testing different drug products like tablets, capsules, modified release formulations and transdermal systems. The document provides details on factors that influence dissolution test design and the principles of operation for each apparatus type.
This document provides an overview of 11 mathematical models that are commonly used to study drug release from pharmaceutical drug delivery systems: 1) Diffusion Model, 2) Zero Order Kinetics Model, 3) First Order Kinetics Model, 4) Higuchi Model, 5) Korsmeyer–Peppas Model, 6) Hixson–Crowell Model, 7) Weibull Model, 8) Baker–Lonsdale Model, 9) Hopfenberg Model, 10) Gompertz model, and 11) Sequential Layer Model. Each model is described in terms of the equations used and their typical applications. The models can help understand drug release mechanisms and optimize drug delivery system design and performance.
This document provides information about small volume parenterals (SVPs). It defines SVPs as injections packaged in containers of 100ml or less. SVPs can include pharmaceutical products, biological products, and more. They are commonly classified as single dose ampoules, single dose vials, multiple dose vials, and prefilled syringes. The document discusses vehicles, additives, processing, and more regarding the formulation and manufacturing of SVPs.
This document discusses drug dissolution, including definitions, theories, mechanisms, factors affecting dissolution, intrinsic dissolution rate, and in-vitro dissolution testing models. It defines dissolution as the mass transfer of a solid substance into a liquid solvent. The key theories discussed are the diffusion layer model, Danckwert's penetration model, and the interfacial barrier model. Factors affecting dissolution include properties of the drug, test conditions, and dosage form characteristics. Common in-vitro dissolution testing models described are non-sink and sink methods that utilize natural or forced convection with varying degrees of agitation.
CO–PROCESSED EXCIPIENTS FOR TABLETS.pdfYamini Shah
Purpose of the present review is to provide an in depth knowledge on recent developments in excipients preparation, technology and approaches involved in their formation and development. Excipients play an important role in dosage form development. In conventional formulation of dosage forms, each excipient is used to provide its required function/performance. Presently, excipient manufacturers have focused their attention on producing a multifunctional excipients with improvement in their performance and quality of dosage form. Manipulation in the functionality of excipient is provided by the co-processing of two or more existing excipients.
Microcapsules: types, preparation and evaluationMOHAMMAD ASIM
This document discusses microcapsules, including their definition, reasons for microencapsulation, types of microcapsules, formulation considerations, preparation techniques, evaluation methods, and applications in pharmacy. Microencapsulation involves enclosing a substance inside a miniature capsule and can be used to increase stability, control release rates, mask tastes/odors, and more. Common preparation techniques include solvent evaporation, spray drying, pan coating, and coacervation. Microcapsules find applications such as taste masking, sustained release, separating incompatibilities, and more in the pharmaceutical industry.
Modeling and comparison of dissolution profiles - Review by Paulo Costa*, Jos...MAHENDRA PRATAP SWAIN
Over recent years, drug release / dissolution from solid pharmaceutical dosage forms has been the subject of intense and profitable scientific developments. Whenever a new solid dosage form is developed or produced, it is necessary to ensure that drug dissolution occurs in an appropriate manner. The pharmaceutical industry and the registration authorities do focus, nowadays, on drug dissolution studies. The quantitative analysis of the values obtained in dissolution / release tests is easier when mathematical formulas that express the dissolution results as a function of some of the dosage forms characteristics are used. In some cases, these mathematics models are derived from the theoretical analysis of the occurring process. In most of the cases the theoretical concept does not exist and some empirical equations have proved to be more appropriate. Drug dissolution from solid dosage forms has been described by kinetic models in which the dissolved amount of drug is a function of the test time. Some analytical definitions of function are commonly used, such as zero order, first order, Hixson–Crowell,Weibull, Higuchi, Baker–Lonsdale, Korsmeyer–Peppas and Hopfenberg models. Other release parameters, such as dissolution time, assay time, dissolution efficacy, difference factor (f1), similarity factor (f2) and Rescigno index can be used to characterize drug dissolution / release profiles.
DRUG RELEASE KINETICS AND MATHEMATICAL MODELLING.pptxDipti Nigam
This document discusses various mathematical models that can be used to model drug release kinetics from formulations. It introduces fundamental concepts like Fick's laws of diffusion and the Noyes-Whitney equation. Several drug release models are described in detail, including zero-order, first-order, Higuchi, Hixson-Crowell, and Korsmeyer-Peppas models. The assumptions and equations of each model are provided. The document also discusses factors that can affect drug release and the importance of understanding release kinetics in drug product development.
This document discusses various parameters used to analyze drug release from pharmaceutical formulations, including diffusion parameters, dissolution parameters, pharmacokinetic parameters, and several kinetic models. It provides details on Higuchi's model, Peppas plot, zero order, first order, and Hixson Crowell models. These models are used to characterize drug release from modified release formulations and determine the drug release mechanism.
This document provides an outline and introduction to dissolution studies. It discusses what dissolution is, why dissolution studies are important, and factors that can affect dissolution. It also covers different dissolution models, including zero order, first order, Higuchi, and diffusion layer models. The models are used to understand drug release kinetics and develop in vitro-in vivo correlations. Dissolution studies are important tests used to evaluate drug release from dosage forms and ensure batch-to-batch quality and bioavailability.
This document discusses mechanisms of drug dissolution from solid oral dosage forms. It begins with an introduction on the importance of dissolution testing. It then covers several theories of dissolution mechanisms including diffusion layer theory, reaction limited models, and the Carstensen scheme. Mathematical models of drug release kinetics are also discussed, including zero-order, first-order, Higuchi, Korsmeyer-Peppas, and Hixson-Crowell models. The document provides details on each model and their applications and limitations in describing drug dissolution and release profiles from different drug delivery systems.
This document discusses various parameters used to characterize drug release from pharmaceutical formulations. It describes diffusion parameters defined by Higuchi's equation and plots. Dissolution parameters like the effects of agitation, pH, temperature, and medium properties are outlined. Pharmacokinetic parameters including Cmax, Tmax, and AUC are defined. The Heckel equation is presented as a method to analyze powder compaction. Similarity factors f1 and f2 are introduced to compare dissolution profiles. The Higuchi and Korsmeyer-Peppas models for drug release are presented.
This document discusses various parameters used to characterize drug release from pharmaceutical formulations, including diffusion parameters described by Higuchi's equation, dissolution parameters like the effects of agitation and pH, and pharmacokinetic parameters like Cmax, Tmax, and AUC. It also covers models like the Heckel equation that can be applied to understand powder compaction and the Korsmeyer-Peppas model for characterizing drug release mechanisms.
The document discusses different models that can be used to describe drug release kinetics from pharmaceutical dosage forms. It describes zero-order, first-order, Korsmeyer, Hixson-Crowell, and Higuchi models. For zero-order kinetics, the drug release is constant with respect to time. The first-order model assumes the dissolution rate is proportional to the amount of drug remaining. These models can provide a mathematical representation of in vitro drug dissolution curves and dissolution profiles.
The document discusses various kinetic models that can be used to describe drug release from pharmaceutical formulations, including zero-order, first-order, Higuchi, Korsmeyer-Peppas, Hixson-Crowell, Weibull, Baker-Lonsdale, Hopfenberg, Gompertz, and sequential layer models. It provides the key equations and applications of each model, with graphics to analyze drug release over time. The models can help optimize drug release kinetics, predict effects of design parameters on release rates, and improve therapeutic efficacy and safety.
Dissolution kinetics and dissolutition modeslsagar Aher
This document discusses various mathematical models that can be used to determine the kinetics of drug release from pharmaceutical dosage forms, including zero-order, first-order, Hixon-Crowell, Higuchi, Korsemeyer-Peppas, and Weibull models. It provides the key equations for each model and describes scenarios in which each model is applicable, such as matrix tablets, coated forms, transdermal systems, and others. The models can be used to analyze drug dissolution data and understand the mechanisms of drug release.
effect of system parameters on controlled release drug deliveryHamedBarzeh
This document discusses how various system parameters affect controlled release drug delivery. It outlines five key parameters: 1) Solution diffusivity, which decreases with increasing solute concentration due to higher viscosity; 2) Thickness of the polymer diffusional path, which increases over time in matrix systems; 3) Thickness of the hydrodynamic diffusion layer, which also varies with the square root of time; 4) Drug loading dose, which influences drug flux but not duration in reservoir systems; and 5) Surface area, where increasing area leads to higher release rates across all controlled delivery systems. The document provides theoretical frameworks and experimental examples for how each parameter influences drug release profiles.
The document discusses diffusion parameters and their importance in understanding drug permeation and distribution. It defines diffusion as the mass transfer of molecules from an area of higher concentration to lower concentration. Studying diffusion parameters helps understand controlled release systems and how factors like solvent penetration rate and swelling layers influence drug release. Fick's laws of diffusion describe diffusion mathematically and diffusion coefficients are affected by concentration, temperature, and solvent properties. Techniques for studying diffusion include measuring diffusion front rates and concentration profiles using methods like microscopy, NMR, and video image processing. Variables that influence diffusion include surface area, thickness of the diffusion boundary layer, diffusion coefficient, and drug solubility. Diffusion is key to rate controlled drug delivery systems where it governs release from
This document discusses several methods for analyzing drug release from formulations, including similarity factors F1 and F2, Higuchi and Korsmeyer-Peppas models, linearity concept of significance, standard deviation, chi-square test, student-t test, and ANOVA test. It provides definitions and applications of these methods. Similarity factors F1 and F2 are used to compare dissolution profiles and determine if they are similar. The Higuchi and Korsmeyer-Peppas models can be used to describe drug release kinetics from matrix systems. Linearity, standard deviation, chi-square, t-test and ANOVA are statistical tests used to determine the significance and accuracy of results.
The document discusses comparison of dissolution profiles through different methods and establishing an IVIVC (in vitro-in vivo correlation). It provides definitions of dissolution profile and objectives of comparing profiles. Various methods for comparing profiles are described, including graphical, statistical, and model-dependent/independent methods. Key factors for determining similarity between dissolution profiles using statistical methods like difference factor and similarity factor are outlined. The importance of developing an IVIVC to reduce costs and the need for bioavailability studies is also mentioned. A research article comparing different brands of metformin tablets using tests like dissolution rate, drug content and disintegration is briefly summarized.
The document discusses various dissolution models that describe drug release from pharmaceutical dosage forms. It begins by defining dissolution and explaining the need for dissolution models. It then describes several common dissolution models - the diffusion layer model, Dankwaet's model, interfacial barrier model, Higuchi model, Korsemeyer-Peppas model, and Baker-Lonsdale model. Each model makes different assumptions about the drug release mechanisms and can be used to analyze dissolution data using mathematical equations. In conclusion, dissolution models provide a quantitative way to interpret dissolution results and describe drug release profiles.
Pharmacokinetics / Biopharmaceutics - Multi compartment IV bolusAreej Abu Hanieh
This document discusses multicompartment models used to describe drug distribution and elimination kinetics. A two-compartment model includes a central compartment representing highly perfused tissues and blood, and a peripheral tissue compartment with slower drug distribution. The plasma concentration curve following intravenous administration has an initial rapid distribution phase as the drug distributes between compartments, followed by a slower elimination phase as the drug is removed from the central compartment. Rate constants describe drug transfer between compartments, and parameters like volume of distribution and half-life can be estimated from the curve.
This presentation discusses kinetics of drug release from controlled release drug delivery systems. It describes different types of controlled release systems including matrix systems, reservoir systems, and dissolution-diffusion controlled systems. Rate controlling steps and drug release mechanisms such as diffusion, erosion, and dissolution are discussed. Factors influencing drug release and diffusion such as temperature, molecular weight, particle size, and viscosity are also summarized. Finally, mathematical models for drug release kinetics including zero-order, first-order, Higuchi, and Korsmeyer-Peppas models are presented.
This document discusses toxicokinetics, which refers to applying pharmacokinetic principles to understand toxicity and adverse effects of drugs and chemicals. It covers several key concepts:
1. Toxicokinetic studies examine systemic exposure after dosing at toxic levels, helping assess safety, while pharmacokinetic studies use lower doses.
2. Models describe the time course of a chemical in the body, including one-compartment open models and multi-compartment models accounting for tissue distribution.
3. Key parameters include volume of distribution, clearance, half-life and how they relate through equations. Non-linear toxicokinetics can occur at high doses due to enzyme saturation.
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This document summarizes a presentation on self-nanoemulsifying drug delivery systems (SNEDDS). SNEDDS are mixtures that spontaneously form nanoemulsions of approximately 200 nm or less upon dilution with water. They consist of oil, surfactant, drug, and co-surfactant or solubilizer. SNEDDS can improve oral bioavailability of hydrophobic drugs by enhancing dissolution rate and permeability as well as reducing first-pass metabolism. Key factors in formulating SNEDDS include selecting oils, surfactants, and co-emulsifiers that enable nanoemulsification as well as considering the drug properties. SNEDDS provide benefits like increased bioavailability, reduced variability, and a potential for
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The document describes the construction and working of a Silverson emulsifier. It consists of a head attached to a central shaft powered by a motor. The head contains turbine blades surrounded by a perforated mesh. Liquids are sucked into the head and subjected to intense mixing by the high-speed blades. This creates small emulsion globules that exit through the mesh openings, producing a fine emulsion. The Silverson emulsifier provides advantages like rapid mixing, particle size reduction, and homogenization through its high-shear action. Occasional clogging of the mesh pores is its main disadvantage.
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- Buffers work by maintaining an equilibrium between an acid and its conjugate base
- Buffer capacity is a measure of a buffer's ability to resist pH changes upon addition of acid or base
- The buffer equation relates pH, pKa, and relative concentrations of the acid and conjugate base
- Buffers have important applications in drug formulations, fermentation, blood plasma, and more to maintain stable and optimal pH levels.
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This document discusses suppositories, which are semisolid dosage forms inserted into body cavities like the rectum. It defines suppositories and describes their types, including rectal, vaginal, nasal, urethral, and ear suppositories. New trends in suppository formulation and packaging are presented, such as tablet, layered, capsule, coated, and disposable suppositories. The mechanisms of local and systemic drug action from suppositories are explained. Advantages include easy administration to children, localized effects, and sustained release of medication. Disadvantages include irritation from some drugs and potential embarrassment for patients.
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This document discusses alpha-amylase inhibitors as an alternative treatment for type 2 diabetes. It begins by introducing diabetes and its causes and symptoms. It then discusses the different types of diabetes and current diabetes medication options. Finally, it focuses on alpha-amylase inhibitors, explaining that they work by inhibiting the alpha-amylase enzyme involved in starch digestion, which helps control post-meal blood sugar spikes for type 2 diabetes patients.
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This document discusses the use of nanocarriers for eye cancer treatment and management. It describes some common types of eye cancer and why nanocarriers are needed due to ocular barriers and risks of damage from repeated injection. The main nanocarriers discussed are liposomes, dendrimers, and carbon nanotubes, along with their advantages such as biocompatibility and drug encapsulation abilities. However, nanocarriers also have disadvantages like limited storage conditions and potential toxicity. In conclusion, the document evaluates nanocarrier strategies for delivering drugs to the eye in a targeted manner for cancer therapy.
Rasamanikya is a excellent preparation in the field of Rasashastra, it is used in various Kushtha Roga, Shwasa, Vicharchika, Bhagandara, Vatarakta, and Phiranga Roga. In this article Preparation& Comparative analytical profile for both Formulationon i.e Rasamanikya prepared by Kushmanda swarasa & Churnodhaka Shodita Haratala. The study aims to provide insights into the comparative efficacy and analytical aspects of these formulations for enhanced therapeutic outcomes.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of the physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar lead (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
6. Describe the flow of current around the heart during the cardiac cycle
7. Discuss the placement and polarity of the leads of electrocardiograph
8. Describe the normal electrocardiograms recorded from the limb leads and explain the physiological basis of the different records that are obtained
9. Define mean electrical vector (axis) of the heart and give the normal range
10. Define the mean QRS vector
11. Describe the axes of leads (hexagonal reference system)
12. Comprehend the vectorial analysis of the normal ECG
13. Determine the mean electrical axis of the ventricular QRS and appreciate the mean axis deviation
14. Explain the concepts of current of injury, J point, and their significance
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. Chapter 3, Cardiology Explained, https://www.ncbi.nlm.nih.gov/books/NBK2214/
7. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
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TEST BANK For An Introduction to Brain and Behavior, 7th Edition by Bryan Kolb, Ian Q. Whishaw, Verified Chapters 1 - 16, Complete Newest Versio
TEST BANK For An Introduction to Brain and Behavior, 7th Edition by Bryan Kolb, Ian Q. Whishaw, Verified Chapters 1 - 16, Complete Newest Version
TEST BANK For An Introduction to Brain and Behavior, 7th Edition by Bryan Kolb, Ian Q. Whishaw, Verified Chapters 1 - 16, Complete Newest Version
Basavarajeeyam is a Sreshta Sangraha grantha (Compiled book ), written by Neelkanta kotturu Basavaraja Virachita. It contains 25 Prakaranas, First 24 Chapters related to Rogas& 25th to Rasadravyas.
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Overall life span (LS) was 1671.7±1721.6 days and cumulative 5YS reached 62.4%, 10 years – 50.4%, 20 years – 44.6%. 94 LCP lived more than 5 years without cancer (LS=2958.6±1723.6 days), 22 – more than 10 years (LS=5571±1841.8 days). 67 LCP died because of LC (LS=471.9±344 days). AT significantly improved 5YS (68% vs. 53.7%) (P=0.028 by log-rank test). Cox modeling displayed that 5YS of LCP significantly depended on: N0-N12, T3-4, blood cell circuit, cell ratio factors (ratio between cancer cells-CC and blood cells subpopulations), LC cell dynamics, recalcification time, heparin tolerance, prothrombin index, protein, AT, procedure type (P=0.000-0.031). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and N0-12 (rank=1), thrombocytes/CC (rank=2), segmented neutrophils/CC (3), eosinophils/CC (4), erythrocytes/CC (5), healthy cells/CC (6), lymphocytes/CC (7), stick neutrophils/CC (8), leucocytes/CC (9), monocytes/CC (10). Correct prediction of 5YS was 100% by neural networks computing (error=0.000; area under ROC curve=1.0).
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1. Dissolution
Model
Presented by- Rajdeepa Kundu(JISU/2022/0198)
Batch-M.Pharm 1st year Pharmaceutics
Under the guidance of – Dr Tapan Kumar Shaw
(Associate professor of JIS university)
2. Dissolution
• According to the IUPAC,the term
“dissolution” is defined as “The mixing of
two phases with the formation of one new
homogeneous phase (i.e. the solution).”
• The “dissolution rate” of a drug in a
liquid is generally defined as the change in
the concentration of dissolved drug
(individualized drug
molecules/ions/atoms), dc, in the time
interval dt:
• dissolution rate = dc/ dt
3. 5 major steps involved in the dissolution of solid
drug particles in a well-stirred aqueous medium
• The surface of the drug particle is wetted with water.
• (b) Solid-state bonds in the drug particle are broken down (e.g. attractive
electrostatic forces in a drug crystal consisting of cations and anions).
• (c) Individualized drug molecules/ions/atoms are surrounded by a shell of water
molecules (“solvation”). (d) The individualized drug molecules/ions/atoms diffuse from
the surface of the drug particle through the liquid, unstirred boundary layer surrounding
the system into the well-stirred bulk fluid. It has to be pointed out that even in
thoroughly stirred aqueous liquids thin unstirred boundary layers exist directly at the
surfaces of the drug particles (due to adhesional forces). The thickness of these
boundary layers is a function of the degree of agitation.
• (e) If the surrounding bulk fluid is well-stirred, the drug molecules/ions/atoms are
transported by convection in the liquid, which is not part of the unstirred boundary
layer: The mass flow created by stirring assures rapid movement of water and
4. Modeling of dissolution profiles
A water-soluble drug incorporated in a matrix is
mainly released by diffusion, while for a low
water-soluble drug the self-erosion of the matrix
will be the principal release mechanism.
• To accomplish these studies the cumulative
profiles of the dissolved drug are more
commonly used.
• To compare dissolution profiles between two
drug products model dependent (curve fitting),
statistic analysis and model independent
methods can be used.
Mathematical models:
• Zero order kinetics
• First-order kinetics
• Weibull model
• Higuchi model
• Hixson–Crowell model
• Korsmeyer–Peppas model
• Baker–Lonsdale model
• Hopfenberg model
• Other release parameters
5. Zero-order
kinetics
Drug dissolution from pharmaceutical dosage forms that do not
disaggregate and release the drug slowly (assuming that area
does not change and no equilibrium conditions are obtained) can be
represented by the following equation.
The pharmaceutical dosage forms following this profiles release the
same amount of drug by unit of time and it is the ideal method of
drug release in order to achieve a pharmacological prolonged
action.
• W0 – Wt = Kt , where W0 is the initial amount of drug in the
pharmaceutical dosage form, Wt is the amount of drug dissolved at
time t and K is a proportionality constant.
Applications: This relation can be used to describe the drug
dissolution of several types of modified release pharmaceutical
dosage forms, as in the case of some transdermal systems, as
well as matrix tablets with low soluble drugs, coated forms,
osmotic systems, etc
6. First-order
kinetics
This model was first proposed by Gibaldi and Feldman (1967) and
later by Wagner (1969).
The dissolution phenomena of a solid particle in a liquid media
implies a surface action, as can be seen by Noyes–Whitney
Equation: dC/dt = K(Cs –C),where C is the concentration of the
solute in time t, Cs is the solubility and K is a first order
proportionality constant.
This equation was altered by Brunner et al. (1900), to incorporate
the value of the solid area accessible to dissolution, S, getting:
dC/dt = K1 S(Cs-C), Where, k1 is a new proportionality constant.
Using the Fick first law, it is possible to establish the following
relation ,for the constant k1 = D/Vh , where D is the solute diffusion
coefficient in the dissolution media, V is the liquid dissolution
volume and h is the width of the diffusion layer.
7. Continue…
Hixson and Crowell adapted the Noyes–Whitney equation in the following manner:
dW/dt = kS(Cs-C), where W is the amount of solute in solution at time t, dW/dt is the
passage rate of the solute into solution in time t and K is a constant.
This last equation is obtained from the Noyes–Whitney equation by multiplying both
terms of equation by V and making K equal to k V. Comparing these terms, the following
relation is obtained: • K= D/h
In this manner, Hixson and Crowell equation can be written as:dW/ dt = KS/V (VCs-W) =
k (VCs-W),Where k = k1S.
If one pharmaceutical dosage form with constant area is studied in ideal conditions (sink
conditions), it is possible to use this last equation that, after integration, will become: W =
VCs (1 – e -kt) .This equation can be transformed, applying decimal logarithms in both
terms, into: Log (VCs- W) = log VCs- (kt/2.303), The data obtained are plotted as log
cumulative percentage of drug remaining vs. time which would yield a straight line with a
slope of-K/2.303
Applications: This relationship can be used to describe drug dissolution in
pharmaceutical dosage forms such as those containing water-soluble drugs in porous
matrices.
8. Hixson–
Crowell
model
Drug powder that having uniformed size particles, Hixson and Crowell derived the
equation which expresses rate of dissolution based on cube root of weight of
particles and the radius of particle is not assumed to be constant.
This is expressed by the equation, M0 1/3 - Mt 1/3 = κ t ,Where, M0 is the initial
amount of drug in the pharmaceutical dosage form, Mt is remaining amount of drug
in the pharmaceutical dosage form at time ‘t’ and κ is proportionality constant.
To study the release kinetics, data obtained from in vitro drug release studies were
plotted as cube root of drug percentage remaining in matrix versus time
Applications: This applies to different pharmaceutical dosage forms such as
tablets, where the dissolution occurs in planes parallel to the drug surface if the
tablet dimensions diminish proportionally, in such a way that the initial geometrical
form keeps constant all the time.
Cube root law- The dissolution data are plotted in accordance with the
Hixson-Crowell cube root law, i.e. the cube root of the initial concentration
minus the cube root of per cent remained, as a function of time. The results
indicates that a linear relationship was obtained in all cases.
9. Higuchi model
This is the first mathematical model that describes drug release from a matrix system, proposed
by Higuchi in 1961.
This model is based on the different hypotheses that (1) Initial drug concentration in the matrix is
much higher than drug solubility, (2) Drug diffusion takes place only in one dimension (Edge
effect should be avoided), (3) Drug particles are much smaller than thickness of system, (4)
swelling of matrix and dissolution are less or negligible, (5) Drug diffusivity is constant, (6)
Perfect sink condition is always attained in the release environment.
Equation-ft = Q = √D(2C-Cs )Cs t , where Q is the amount of drug released in time t per unit
area, C is the drug initial concentration, Cs is the drug solubility in the matrix media and D is the
diffusivity of the drug molecules (diffusion constant) in the matrix substance.
Higuchi describes drug release as a diffusion process based in Fick’s law, square root time
dependent. The data obtained were plotted as cumulative percentage drug release versus
square root of time
Applications: This relationship can be used to describe the drug dissolution from several types
of modified-release pharmaceutical dosage forms, as in the case of some transdermal systems
and matrix tablets with water-soluble drugs.
10. Korsmeyer–
Peppas
model
Nicholas Peppas was the first to introduce this equation in the field of drug delivery
(Peppas, 1985).
Clearly, the classical Higuchi equation as well as the above-described short time
approximation of the exact solution of Fick’s second law for thin films with initial drug
concentrations, which are below drug solubility (monolithic solutions)
Frequently used and easy-to-apply model to describe drug release Peppas equation, or
power law: Mt/M∞= kt n , Here, Mt and M∞ are the absolute cumulative amount of drug
released at time t and infinite time, respectively; k is a constant incorporating structural and
geometric characteristics of the system, and n is the release exponent, which might be
indicative of the mechanism of drug release.
Used when a release exponent of 0.5 can serve as an indication for diffusion-controlled
assumptions drug release, but only if all these particular solutions are based on are
fulfilled, for example film geometry with negligible edge effects, time- and position-
independent diffusion coefficients in a non-swellable and insoluble matrix former
Applications: This equation has been used to the linearization of release data from
several formulations of microcapsules or microspheres.
11.
12. Comparison of dissolution
profiles
The drug-release profiles can be analyzed using the f2 metrics
mathematical equation that compares drug-release curves.
• f2 metric is the similarity factor, and values of f2 between 50 and
100 suggest profile similarity. A value less than 50 represents a
significant difference and equates to a greater than 10% dissolved
difference between the two drug-release curves.
• Rt represents the reference profile, Tt represents the test profile
where (n) is the number of data points collected.
Equation:
Difference
factor(F1)
Similarity
factor(F2)
innference
0 100 Dissolution
profile are
similar
<=15 50 Similarity
or
equivalenc
e of 2
profile
13. Reference
Cartensen JT; Modeling and data treatment
in the pharmaceutical sciences. Technomic
Publishing Co. Inc., New York, Basel
1996
Ramteke KH, Dighe PA, Kharat AR, Patil
SV. Mathematical models of drug
dissolution: a review. Sch. Acad. J. Pharm.
2014 Jan;3(5):388-96.
2014