Podcast
Questions and Answers
What is the primary driving force for the rate of dissolution?
What is the primary driving force for the rate of dissolution?
- Concentration gradient (correct)
- Thickness of the diffusion layer
- Surface area of the drug particles
- Polymorphism
What is the purpose of sink conditions in dissolution testing?
What is the purpose of sink conditions in dissolution testing?
- To enhance the polymorphism of the drug
- To increase the surface area of the drug particles
- To decrease the thickness of the diffusion layer
- To ensure that the dissolution medium is not saturated with the drug (correct)
How can the concentration gradient be increased?
How can the concentration gradient be increased?
- By decreasing the surface area of the drug particles
- By decreasing the concentration of the drug in the dissolution medium (correct)
- By decrasing the thickness of the diffusion layer
- By increasing the polymorphism of the drug
What is the effect of agitation on the thickness of the diffusion layer?
What is the effect of agitation on the thickness of the diffusion layer?
What is the relationship between the concentration gradient and the rate of dissolution?
What is the relationship between the concentration gradient and the rate of dissolution?
What is the effect of polymorphism on the dissolution of a drug?
What is the effect of polymorphism on the dissolution of a drug?
What is the purpose of using a large volume of dissolution medium?
What is the purpose of using a large volume of dissolution medium?
What is the term for the finished dosage form that contains a drug substance, mostly associated with other inactive ingredients?
What is the term for the finished dosage form that contains a drug substance, mostly associated with other inactive ingredients?
What is the process by which the drug leaves a drug product?
What is the process by which the drug leaves a drug product?
What is the process by which drug molecules are liberated from a solid phase and enter into a solution phase?
What is the process by which drug molecules are liberated from a solid phase and enter into a solution phase?
What is the main purpose of dissolution testing?
What is the main purpose of dissolution testing?
What is the term for the assessment of the rate by which the drug molecules are dissolved and released from the dosage form?
What is the term for the assessment of the rate by which the drug molecules are dissolved and released from the dosage form?
What is the characteristic of dissolution?
What is the characteristic of dissolution?
Why is dissolution testing important for dosage forms that have the drug present in the solid state?
Why is dissolution testing important for dosage forms that have the drug present in the solid state?
What is the relationship between dissolution and absorption of a drug?
What is the relationship between dissolution and absorption of a drug?
What is the primary objective of performance testing in pharmaceutical dosage forms?
What is the primary objective of performance testing in pharmaceutical dosage forms?
What is the typical speed of the Rotating Basket dissolution apparatus?
What is the typical speed of the Rotating Basket dissolution apparatus?
What is the primary purpose of selecting discriminatory dissolution conditions?
What is the primary purpose of selecting discriminatory dissolution conditions?
Which of the following dissolution apparatus is recommended for orally disintegrating tablets?
Which of the following dissolution apparatus is recommended for orally disintegrating tablets?
What type of dissolution medium is used in in vitro - in vivo correlation studies?
What type of dissolution medium is used in in vitro - in vivo correlation studies?
What is the name of the dissolution apparatus used for testing chewing gum?
What is the name of the dissolution apparatus used for testing chewing gum?
What is the purpose of selecting a specific dissolution medium?
What is the purpose of selecting a specific dissolution medium?
What characteristic of biorelevant media makes them more accurate than other dissolution media?
What characteristic of biorelevant media makes them more accurate than other dissolution media?
What is the primary difference between immediate-release and extended-release tablets?
What is the primary difference between immediate-release and extended-release tablets?
Which of the following dosage forms is typically tested using the Franz-cell apparatus?
Which of the following dosage forms is typically tested using the Franz-cell apparatus?
Why are dissolution conditions not chosen to mimic in vivo conditions?
Why are dissolution conditions not chosen to mimic in vivo conditions?
What is the primary factor in selecting a dissolution apparatus for a particular dosage form?
What is the primary factor in selecting a dissolution apparatus for a particular dosage form?
What is the purpose of dissolution testing?
What is the purpose of dissolution testing?
What is the purpose of quantifying the amount of drug released during performance testing?
What is the purpose of quantifying the amount of drug released during performance testing?
What is the pH of simulated gastric fluid?
What is the pH of simulated gastric fluid?
What is the purpose of biorelevant media in drug dissolution?
What is the purpose of biorelevant media in drug dissolution?
What is the temperature maintained at in the dissolution apparatus?
What is the temperature maintained at in the dissolution apparatus?
What is the function of Noyes Whitney in drug dissolution?
What is the function of Noyes Whitney in drug dissolution?
What is the composition of simulated intestinal fluid?
What is the composition of simulated intestinal fluid?
What is the purpose of Fick's Law in drug dissolution?
What is the purpose of Fick's Law in drug dissolution?
Flashcards
Drug product
Drug product
A finished dosage form containing a drug substance and inactive ingredients.
Drug release
Drug release
The process where a drug leaves a drug product.
Dissolution
Dissolution
Drug molecules dissolving from a solid into a solution.
Dissolution testing
Dissolution testing
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Concentration gradient
Concentration gradient
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Diffusion layer
Diffusion layer
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Surface area
Surface area
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Performance testing
Performance testing
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Dissolution apparatus
Dissolution apparatus
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Dissolution medium
Dissolution medium
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Apparatus I
Apparatus I
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Apparatus II
Apparatus II
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Apparatus III
Apparatus III
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Biorelevant media
Biorelevant media
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Noyes-Whitney equation
Noyes-Whitney equation
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Oral suspensions
Oral suspensions
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Orally disintegrating tablets
Orally disintegrating tablets
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Chewable tablets
Chewable tablets
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Transdermal patches
Transdermal patches
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Semisolid topical dosage forms
Semisolid topical dosage forms
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Sink Conditions
Sink Conditions
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In-vivo Conditions
In-vivo Conditions
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In-vitro Testing
In-vitro Testing
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Study Notes
Definitions and Importance
- A drug product is a finished dosage form that contains a drug substance mostly associated with other inactive ingredients.
- Drug release is the process by which the drug leaves a drug product.
- Dissolution is the process by which drug molecules are liberated from a solid phase and enter a solution phase.
Dissolution vs. Solubility
- Dissolution testing, also known as in-vitro drug release testing, measures the release of the active pharmaceutical ingredient (API) from the drug product matrix in a controlled laboratory environment.
- Dissolution is a time-dependent (or kinetic) process that involves mass transfer (like diffusion).
Factors Affecting Dissolution
- Concentration gradient: An increase in concentration gradient increases the rate of dissolution, and can be increased by decreasing the thickness of the diffusion layer or using large volumes of dissolution medium.
- Thickness of the diffusion layer (h): Decreased agitation increases the thickness of the diffusion layer, which decreases the rate of dissolution.
- Surface area of drug particles (S): Increased surface area of drug particles increases the rate of dissolution.
Methodology
- Performance testing involves subjecting the dosage form to a set of conditions that will induce drug release from the dosage form and quantifying the amount of drug released under those conditions.
- Conditions include the selection of dissolution apparatus (type and speed) and dissolution medium (sink conditions and temperature).
Official Dissolution Apparatus
- Apparatus I: Rotating Basket (50 rpm)
- Apparatus II: Paddle
- Apparatus III: Reciprocating cylinder (“Bio-Dis")
- Apparatus IV: Flow-through cell
- Apparatus V: Paddle over disk
- Apparatus VI: Rotating Cylinder
- Apparatus VII: Reciprocating Holder
- European Pharmacopeia: Chewing gum apparatus
Choice of Apparatus
- Dosage Forms:
- Oral suspensions: USP Apparatus 2
- Orally disintegrating tablets: USP Apparatus 2
- Chewable tablets: USP Apparatus 2 or 3
- Transdermal patches: USP Apparatus 5
- Semisolid topical dosage forms: Franz-cell, enhancer cell
Special Considerations
- Dissolution conditions should be discriminatory, capable of reflecting a change in drug release profile related to a change in the drug product.
- Dissolution conditions are generally selected to simulate in-vivo conditions, not mimic them.
- Biorelevant media simulate gut fluids accurately, containing components that replicate conditions found in the GIT.
Biorelevant Medium
- Biorelevant media contain components like bile salts, phospholipids, and salts that simulate gut fluids accurately.
Noyes-Whitney Equation
- The Noyes-Whitney equation describes the dissolution rate of a drug molecule.
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Description
This quiz covers the concepts of dissolution, Noyes-Whitney equation, and factors affecting dissolution in physical pharmacy, taught by Professor Ragwa Farid.
