The document discusses various physicochemical properties that can affect bioequivalence studies, including crystal morphology, polymorphism, solvates, hydrates, complexation, surface activity, hygroscopicity, particle size, solubility and dissolution. It explains how these properties can influence parameters like raw material characteristics, reproducibility, performance of the dosage form, absorption rate and extent. Factors like ionization, partitioning, distribution coefficient, chemical structure and salt forms are also covered in relation to their effects on solubility, dissolution and absorption of drug substances and products.
Polymorphism is very important in those areas of chemical research where full
characterization of a material has a pivotal role in determining its ultimate use, e.g., in
pharmaceutical, pigment, agrochemical, explosive, and fine chemical industries.
Polymorphism has been recognized as an important element of drug development
Polymorphic forms of a drug substance can have different chemical and physical
properties, including melting point, chemical reactivity, apparent solubility, apparent
solubility, dissolution rate, optical, electrical, and mechanical properties, vapor pressure,
stability, and density.
These properties can have a direct effect on the ability to process and/or manufacture the
drug substance and the drug product, as well as on drug product stability, dissolution, and
bioavailability.
Polymorphism is very common among pharmaceutical substances and thermodynamic
stability of a polymorph can impact pharmaceutical properties such as bioavailability,
processability and manufacturability.
Polymorphic forms possess higher potential energy with respect to the
thermodynamically stable or lowest entry forms.
Different polymorphic phase’s exhibit unique physicochemical properties include
solubility, dissolution rates which can influence bioavailability.
The ability to isolate, differentiate, and characterize individual polymorphs is a major
challenge to the pharmaceutical industry.
PHARMACEUTICAL APPLICATIONS OF POLYMORPHISM
- Improved physical stability
- Ease of handling
- Improved bioavailability
- Better chemical stability
- Sustained release
United State Pharmacopoeia (USP)The establishment of a rational relationship between a biological property, or a parameter derived from a biological property produced by a dosage form, and a physicochemical property or characteristic of the same dosage form.
Food and Drug Administration (FDA) definitionIVIVC is a predictive mathematical model describing the relationship between an in vitro property of a dosage form and a relevant in vivo response. Generally, the in vitro property is the rate or extent of drug dissolution or release while the in vivo response is the plasma drug concentration or amount of drug absorbed.
Polymorphism is very important in those areas of chemical research where full
characterization of a material has a pivotal role in determining its ultimate use, e.g., in
pharmaceutical, pigment, agrochemical, explosive, and fine chemical industries.
Polymorphism has been recognized as an important element of drug development
Polymorphic forms of a drug substance can have different chemical and physical
properties, including melting point, chemical reactivity, apparent solubility, apparent
solubility, dissolution rate, optical, electrical, and mechanical properties, vapor pressure,
stability, and density.
These properties can have a direct effect on the ability to process and/or manufacture the
drug substance and the drug product, as well as on drug product stability, dissolution, and
bioavailability.
Polymorphism is very common among pharmaceutical substances and thermodynamic
stability of a polymorph can impact pharmaceutical properties such as bioavailability,
processability and manufacturability.
Polymorphic forms possess higher potential energy with respect to the
thermodynamically stable or lowest entry forms.
Different polymorphic phase’s exhibit unique physicochemical properties include
solubility, dissolution rates which can influence bioavailability.
The ability to isolate, differentiate, and characterize individual polymorphs is a major
challenge to the pharmaceutical industry.
PHARMACEUTICAL APPLICATIONS OF POLYMORPHISM
- Improved physical stability
- Ease of handling
- Improved bioavailability
- Better chemical stability
- Sustained release
United State Pharmacopoeia (USP)The establishment of a rational relationship between a biological property, or a parameter derived from a biological property produced by a dosage form, and a physicochemical property or characteristic of the same dosage form.
Food and Drug Administration (FDA) definitionIVIVC is a predictive mathematical model describing the relationship between an in vitro property of a dosage form and a relevant in vivo response. Generally, the in vitro property is the rate or extent of drug dissolution or release while the in vivo response is the plasma drug concentration or amount of drug absorbed.
It is defined as “the predictive mathematical model that describes the relationship between in vitro property (such as rate & extent of dissolution) of a dosage form and in vivo response (such as plasma drug concentration or amount of drug absorbed)”.
Pharmacokinetics (Greek: Kinesis—movement)
This refers to movement of the drug in and alteration of the drug by the body; includes absorption, distribution, binding/ localization/ storage, biotransformation and excretion of the drug.
Bioavailability: is a subcategory of absorption.
Bioavailability is a measurement of the rate and extent to which a drug reaches at the site of action determined by its concentration-time curve in blood or by its excretion in urine.
Two preparations of a drug are considered bioequivalent when the rate and extent of bioavailability of the active drug from them is not significantly different under suitable test conditions
The clearance of a drug is the theoretical volume of plasma from which the drug is completely removed in unit time.
Stability studies ensuring the maintenance of product quality, safety and efficacy throughout the shelf life are considered as pre-requisite for the acceptance and approval of any pharmaceutical product. Stability testing is a routine procedure performed on drug substances and products and is employed at various stages of the product development.
drug execipent compatibilty studies is of prime importance for the better formulation of the new drug and also for reducing cost by verfication of the data at the earlier atage.
this presentation will give the brief explanation of the goal, importance, dteps involve to studi the drug execient compatibility studies with different examples suitable accordiingly.
Sustained release, are terms used to identify drug delivery system that are designed to achieve a prolonged therapeutic effect by continuously releasing medication over an extended period of time after administration of a single dose.
Sustained release dosage forms provide an
amount of drug initially made available to the body
to cause the desired therapeutic response, followed
by a constant release of medication for maintenance
of activity over a period of time
Methods of enhancing Dissolution and bioavailability of poorly soluble drugsRam Kanth
Greetings!
Good Day to all...
Topic: Methods of Enhancing Bioavailability
Several approaches discussed are
1. Micrnoization
2. Use of Surrfactants
3. Use of Salt forms
4. Alteration of pH of microenvironment
5. Use of metastable polymorphs
6. Solute-Solvent Complexation
7. Solvent Deposition
8. Selective Adsorption on Insoluble Carriers
9. Solid Solutions
10. Eutectic Mixtures
11. Solid Dispersions
12. Molecular Encapsulation with Cyclodextrins
Please do clarify for doubts if any....
Thank you all for watching this presentation.
It is defined as “the predictive mathematical model that describes the relationship between in vitro property (such as rate & extent of dissolution) of a dosage form and in vivo response (such as plasma drug concentration or amount of drug absorbed)”.
Pharmacokinetics (Greek: Kinesis—movement)
This refers to movement of the drug in and alteration of the drug by the body; includes absorption, distribution, binding/ localization/ storage, biotransformation and excretion of the drug.
Bioavailability: is a subcategory of absorption.
Bioavailability is a measurement of the rate and extent to which a drug reaches at the site of action determined by its concentration-time curve in blood or by its excretion in urine.
Two preparations of a drug are considered bioequivalent when the rate and extent of bioavailability of the active drug from them is not significantly different under suitable test conditions
The clearance of a drug is the theoretical volume of plasma from which the drug is completely removed in unit time.
Stability studies ensuring the maintenance of product quality, safety and efficacy throughout the shelf life are considered as pre-requisite for the acceptance and approval of any pharmaceutical product. Stability testing is a routine procedure performed on drug substances and products and is employed at various stages of the product development.
drug execipent compatibilty studies is of prime importance for the better formulation of the new drug and also for reducing cost by verfication of the data at the earlier atage.
this presentation will give the brief explanation of the goal, importance, dteps involve to studi the drug execient compatibility studies with different examples suitable accordiingly.
Sustained release, are terms used to identify drug delivery system that are designed to achieve a prolonged therapeutic effect by continuously releasing medication over an extended period of time after administration of a single dose.
Sustained release dosage forms provide an
amount of drug initially made available to the body
to cause the desired therapeutic response, followed
by a constant release of medication for maintenance
of activity over a period of time
Methods of enhancing Dissolution and bioavailability of poorly soluble drugsRam Kanth
Greetings!
Good Day to all...
Topic: Methods of Enhancing Bioavailability
Several approaches discussed are
1. Micrnoization
2. Use of Surrfactants
3. Use of Salt forms
4. Alteration of pH of microenvironment
5. Use of metastable polymorphs
6. Solute-Solvent Complexation
7. Solvent Deposition
8. Selective Adsorption on Insoluble Carriers
9. Solid Solutions
10. Eutectic Mixtures
11. Solid Dispersions
12. Molecular Encapsulation with Cyclodextrins
Please do clarify for doubts if any....
Thank you all for watching this presentation.
The presentation provides a concise information regarding various methods or techniques for enhancing solubility of different drugs and will prove useful to students & researchers.
This slide contains the preformulation studies.It contains the various physicochemical properties that must be undergo to formulate the better absorption and stabiity of the different type of dosage form.This is ultimately used for the B Pharmacy final year students.Download the colourful ppt and enjoy the experience.
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Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
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This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
2. What is Bioequivalence
• It is a relative term which denotes that the drug substance in two or more
identical dosage forms, reaches the systemic circulation at the same relative
rate and to the same relative extent i.e. their plasma concentration-time
profiles will be identical without significant statistical differences.
• When statistically significant differences are observed in the bioavailability
of two or more drug products, bio-inequivalence is indicated.
5. Crystal Morphology
• A crystalline species can be defined as the solid that is composed of the
atoms, ions or molecules arranged in a three dimensional pattern.
• Crystallization is invariably employed as the final step for the purification of
solid.
• Changes in crystal habit leads to significant variations in the raw material.
• Various dosage form parameters like flowability, particle orientation,
compaction, suspension stability and dissolution can be altered significantly
because of different crystal habits.
6. continued
• Changes in crystal leads to polymorphic transformation
morphology and
serious implications of physical
stability in dosage forms
Remedy- To minimize raw material characteristics
To ensure reproducibility and to judje poor performance of the
dosage form
Recognize the importance of changes in crystal surface appereance and
habit of pharmaceutical powders.
7. Polymorphism
• Both organic and inorganic pharmaceutical compounds can crystallize into
two or more solid forms that have the same chemical composition and is
called as polymorphism.
• Polymorphs have different relative intermolecular and/or interatomic
distances as well as unit cells, resulting in different physical and chemical
properties such as density, solubility, dissolution rate, bioavailability, etc.
• Polymorphs and pseudopolymorphs can be also classified as either
monotropes or enantiotropes, depending upon whether or not one form can
transform reversibly to another.
10. Continued
• It has been suggested that almost 40% of all organic compounds can exist in
various polymorphic forms; sometimes in as many as five different forms, as
in the case of cortisone acetate; almost 50% of all barbiturates and 70% of
steroids exhibit polymorphism.
11. Methods to determine
• Optical crystallography
• Hot stage microscopy
• x ray diffraction method
• Differential Thermal Analysis (DTA)
• Differential Scanning Calorimetric (DSC)
• Thermo Gravimetric Analysis (TGA)
12. Parameter to checked by preformulator
1.No of polymorphs
2. Relative degree of stability
3. Presence of glassy state
4. Stabilization of metastable form
5. Temperature stability range
6. Solubility of each polymorph
7. Method of preparation
8. Effect of micronization
9. Excipients incompatibility
13. Solvates
• In additions to polymorphs, solvates (inclusion of the solvent of
crystallization) are also often formed during the crystallization process.
• These forms are also called pseudopolymorphs.
• If the solvate contains an organic solvent, this would not be admitted
by regulatory authorities.
14. Types of solvents
• Class 1- Avoid these as per ICH eg-benzene,
carbon tetrachloride,1,2-dichloromethane
• Class 2- Should be limited and include non-genotoxic
animal carcinogens such as cyclohexane, acetonitrile
• Class 3- have low-toxicity potential including acetic acid,and
acetone and usually permissible
15. • The solvates themselves may exist in various polymorphic forms and are
referred to as pseudopolymorphs.
• Some examples of pseudopolymorphs include mercaptopurine,
fluprednisolone, and succinylsulfathiazole.
• The number of drug solvates is well over 100 and some of the most
common examples include steroids, antibiotics, sulfonamides,
barbiturates, xanthines, and cardiac glycosides..
16. Hydrates
• When solvate happens to be water, these are called hydrates
wherein water is entrapped through hydrogen bonding inside the
crystal and strengthens crystal structure and thereby invariably
reduces the dissolution rate.
• Solvate water
Hydrates Reduces Dissolution rate
Crystalline hydrates are classified into three classes as follows:
17. • Class I includes isolated lattice sites, represent the structures with
water molecules that are isolated and kept from contacting other
water molecules directly in the lattice structure.
• Therefore, water molecules exposed to the surface of crystals may be
easily lost.
• Class II includes hydrates that have water molecules in channels.
The water molecules in this class lie continuously next to the other
water molecules, forming channels through the crystal.
• Class III includes ion-associated hydrates. Hydrates contain metal-
ion coordinated water and the interaction between the metal ions and
water molecules is the major force in the structure of crystalline
hydrates.
19. Complexation
• A molecular complex consists of constituents held together by
weak forces such as hydrogen bonds.
• Complexation will generally increase the total solubility of a
poorly water-soluble drug if the complex itself is soluble in
aqueous media.
• If the complexation process is reversible (Drug+Complexing
agent complex) then the absorption rates and the extent of
absorption will be increased for poorly soluble drugs.
• The most frequently observed complex formation is between
various drugs and macromolecules, such as gums, cellulose
derivatives, high-molecular weight polyols and nonionic
surfactants.
21. Surface Activity
• The lowering of surface tension increases the dissolution rates by
increasing the solubility of drugs if the concentration of the surfactant
is above the critical micelle concentration.
• The lowering of surface tension also increases the diffusion of free
molecules in the medium, increasing the contact between free drug
and the absorption surface.
• A number of drugs have surface active properties themselves and form
their own micelles, thus facilitating the absorption.
• Examples of these drugs include potassium benzyl penicillin, mixtures
of penicillin and streptomycin salts, amphetamine sulfate,
cyclopentamine hydrochloride, ephedrine sulfate, propoxyphene
hydrochloride, ionic derivatives of phenothiazines, dyes, quarternary
ammonium salts of drugs, and liquorice.
23. Hygroscopicity
• Water molecules have polar ends and readily form hydrogen
bonding. As a result, several compounds interact with water
molecules by surface adsorption, condensation in capillaries,
bulk retention, and chemical interaction and are called
hygroscopic.
• In tightly bound state, the water molecules are generally not
available to induce chemical reactions.
• Free water molecules can participate in the creation of a liquid
environment around crystal lattice where the pH may be altered
due to dissolution process.
24. Particle Size
• Increased absorption due to reduction of particle size is a result
of increased dissolution, which is in turn the result of a larger
specific surface area being exposed to the fluids in the
gastrointestinal tract or other sites of administration.
• Reduction in particle size can be achieved by several methods,
including milling, grinding, precipitating the drug on an
absorbent, and dispersing the drug in an inert watersoluble
carrier (referred to as a solid dispersion).
• The conventional methods of particle size reduction have long
been employed to improve the bioavailability of drugs,
• some of these examples include: vitamin A, medroxyprogesterone
acetate, 4-Acetamidophenyl 2,2,2-trichlorethyl carbonate,
nitrofurantoin, aspirin, phenobarbital, bishydroxycoumarin,
phenacetin
25. Not always desirable
• Nitrofurantoin, when administered in its fine particle size, causes
more gastrointestinal irritation than when administered in its coarser
size.
• This is due to the higher plasma and gastrointestinal concentrations
resulting from use of a fine particle size.
• The use of the coarser size is therefore preferred even though this
results in retarded absorption.
• Eg 2- When chemical instability is a problem the reduction of particle
size is also contraindicated, as with penicillin G and erythromycin,
which decompose in the gastrointestinal tract quickly.
• Even in the solid state a small particle size means a greater surface
area available for the absorption of moisture, which can result in an
increased rate of decomposition
26. SOLUBILITY
• The discussions of pKa, log P, log D above is relevant to
understanding the factors that affect the solubility of a drug at
the site of administration and thus determining the activity,
toxicity, stability, and dosage form and route of administration.
• High solubility is defined as the highest dose strength that is
soluble in 250 mL or less of aqueous media across the physiologic
pH range.
• Poorly soluble drugs can be defined as those with an aqueous our
solubility of less than 100 mg/mL.
28. Thumb rules
• Electrolytes dissolve in conducting solvents.
• Solutes having significant dipole moments dissolve in solvents
having significant dipole moments.
• Solutes with low or zero dipole moments dissolve in solvents
with low or zero dipole moments.
• Like dissolves like
29. Classes of solvents
• Protic solvents such as methanol and formamide which are
hydrogen bond donors,
• Dipolar aprotic solvents (e.g., acetonitrile nitrobenzene) with
dielectric constants greater than 15 but which cannot form
hydrogen bonds with the solute.
• Aprotic solvents in which the dielectric constant is weak and the
solvent is nonpolar, e.g.,pentane or benzene.
30. DISSOLUTION
• Dissolution is the conversion of solid state (highly aggregated
state) to a solution state (highly dispersed state).
• The dissolution models are derived from the known principles of
physics and chemistry such as Fick’s laws of diffusion,
concentration, or chemical potential gradients and the
hydrodynamic principles.
31. Types of models
• Diffusion Model
• Convection Model
• Surface Reaction Model
• Cube-Root Model
• Tablet Dissolution Model
• Noyes–Whitney Model
32. 2. Chemical factors
• Ionization
• Partitioning
• Distribution coefficient
• Chemical Structure and Form
• Salt Forms
33. Ionization
• Chemical moieties are known to attract to each other and under
appropriate conditions ,disassociate; when this process is driven
by the electrical charges on the components of the moiety, this
phenomenon, known as ionization.
• Acids give rise to excess of H+ in aqueous solution whereas a
base gives rise to excess of OH- in solution (Brønsted–Lowry
theory).
• A more general theory of acids and bases is the Lewis theory
wherein when an H+ ion combines with an OH- ion to form
water
34. Henderson–Hasselbach equation
• The Henderson–Hasselbach equation defines the relationship
between ionization and pH
• where [A–] is the concentration of the dissociated species and
[HA] is the concentration of the undissociated species.
35.
36. pH partition hypothesis
• The theory states that for drugs of compounds having molecular
weight greater than 100 which are primarily transported across
the membrane by diffusion, the process of absorption is governed
by
• 1.The dissociation constant of the drug (Pka)
• 2.The lipid solubility on unionized drug
• 3.The pH of absorption site
Assumptions of hypothesis:
1. The GIT is a simple lipoidal barrier to the transportation of the drug
2. Larger the fraction of unionized drug faster is the absorption
3. Greater the lipophilicity of unionized drug better is absorption.
39. Partitioning
• The partition coefficient is a measure of the extent a substance
partitions between two phases, generally an oil phase and an
aqueous phase. This ratio is often expressed as log P (logarithm
of partition ratio).
• Both pKa and log P measurements are useful parameters in
understanding the dissolution and absorption behavior of drug
molecules.
• The pKa will determine the species of molecules, which is likely
to be present at the site of absorption and how quickly or
completely the species would cross a large number of transport
barriers in the body, regardless of the route of administration.
40. Partitioning
It is worth noting that this is a logarithmic scale, therefore, a log P=0 means that the
compound is equally soluble in water and in the partitioning solvent.
If the compound has a log P=5, then the compound is 100,000 times more soluble in the
partitioning solvent.
A log P=(-2) means that the compound is 100 times more soluble in water, i.e., it is quite
hydrophilic.
41. Partitioning
• Generally, compounds with log P values between 1 and 3 show
good absorption, whereas those with log P values greater than 6
or less than 3 often have poor transport characteristics.
• Highly nonpolar molecules have a preference to reside in the
lipophilic regions of membranes, and very polar compounds show
poor bioavailability because of their inability to penetrate
membrane barriers.
42. Distribution Coefficient
• If the drug has more than one ionization center, the distribution
of species present will depend on the pH.
• The concentration of the ionized drug in the aqueous phase will
therefore have an effect on the overall observed partition
coefficient.
• This leads to the definition of the distribution coefficient (log D)
of a compound, which takes into account the dissociation of weak
acids and bases.
43. Chemical Structure and Form
• Many important drugs are weak acids or bases.
• Salts of acidic or basic drugs have different solubility characteristics
and show different bioavailability.
• Sodium or potassium salts of weak acids dissolve much more rapidly
than the corresponding free acids, regardless of the pH of the
dissolution medium.
• The same is usually true of the hydrochloride salts or other strong acid
salts of weak bases, such as tetracycline hydrochloride, or atropine
sulfate.
• The salt form of the drug is generally more soluble in an aqueous
medium. However, the solubility of the salt depends on the strength
and quantity of the counterions; the smaller the counterion the more
soluble is the salt.
• For example, p-Amino salicylic acid (PAS) exists in various salt forms
and their solubility is given in following table
44.
45. Not always desirable
• However, the use of salt forms is not always desirable such as demonstrated
for several drugs as listed in the table