Podcast
Questions and Answers
What does Fick's First Law of Diffusion state?
What does Fick's First Law of Diffusion state?
- The rate of diffusion is proportionate to cross-sectional area and diffusion coefficient only
- The rate of diffusion is proportionate to concentration gradient, cross-sectional area, and diffusion coefficient (correct)
- The rate of diffusion is proportionate to concentration gradient and diffusion coefficient only
- The rate of diffusion is proportionate to concentration gradient and cross-sectional area only
What does the diffusion coefficient (D) represent?
What does the diffusion coefficient (D) represent?
- The concentration of solute in g/mL of solution
- The decrease in chemical potential/free energy
- The rate of diffusion in a specific solvent at a specific temperature
- The amount of solute diffusing across 1 cm$^2$ in 1 second (correct)
What does the flux (J) measure in diffusion?
What does the flux (J) measure in diffusion?
- The amount of substance that will flow through a unit area during a unit time interval (correct)
- The rate of diffusion of a specific solute
- The decrease in chemical potential/free energy
- The concentration gradient of the solute
When does diffusion stop according to the text?
When does diffusion stop according to the text?
What is the main buffer system in the small intestine?
What is the main buffer system in the small intestine?
What is the approximate fasting pH range in the duodenum of the small intestine?
What is the approximate fasting pH range in the duodenum of the small intestine?
What is the approximate fasting pH in the jejunum of the small intestine?
What is the approximate fasting pH in the jejunum of the small intestine?
What is the fasting concentration of bile salts in the small intestine?
What is the fasting concentration of bile salts in the small intestine?
What is the approximate concentration of bile salts in the small intestine in the fed state?
What is the approximate concentration of bile salts in the small intestine in the fed state?
What is the approximate bile salt/phospholipids ratio in the small intestine?
What is the approximate bile salt/phospholipids ratio in the small intestine?
What is the approximate surface area of the intestine needed for sufficient oral absorption?
What is the approximate surface area of the intestine needed for sufficient oral absorption?
What does the Biopharmaceutical Classification System (BCS) classify based on for oral drug absorption?
What does the Biopharmaceutical Classification System (BCS) classify based on for oral drug absorption?
What is the effective permeability (Peff) of the intestine for drug absorption?
What is the effective permeability (Peff) of the intestine for drug absorption?
Which BCS class of drugs may qualify for a waiver of in vivo bioavailability and bioequivalence studies?
Which BCS class of drugs may qualify for a waiver of in vivo bioavailability and bioequivalence studies?
What is the approximate transit time of drug absorption in the stomach in the fasting state?
What is the approximate transit time of drug absorption in the stomach in the fasting state?
What is the approximate transit time of drug absorption in the intestines in the fasting state?
What is the approximate transit time of drug absorption in the intestines in the fasting state?
What is the driving force for the transfer of one molecule across a distance?
What is the driving force for the transfer of one molecule across a distance?
What is the counterforce to diffusion that allows systems to reach homogeneity?
What is the counterforce to diffusion that allows systems to reach homogeneity?
What is the function of the diffusion coefficient related to?
What is the function of the diffusion coefficient related to?
What phenomenon occurs when a solution is allowed to stand unagitated and the force of gravity acts?
What phenomenon occurs when a solution is allowed to stand unagitated and the force of gravity acts?
What is the greater affect than gravity in ultracentrifugation?
What is the greater affect than gravity in ultracentrifugation?
What does Fick’s 2nd Law of Diffusion explain?
What does Fick’s 2nd Law of Diffusion explain?
When does diffusion slow down according to Fick’s 2nd Law of Diffusion?
When does diffusion slow down according to Fick’s 2nd Law of Diffusion?
What is the goal of establishing sink conditions in diffusion?
What is the goal of establishing sink conditions in diffusion?
What is the method used to determine the diffusion coefficient in a two-chamber vessel separated by a porous membrane?
What is the method used to determine the diffusion coefficient in a two-chamber vessel separated by a porous membrane?
What is the mass transfer of molecules based on a concentration gradient known as?
What is the mass transfer of molecules based on a concentration gradient known as?
What is the equation for flux (J) in the determination of diffusion coefficient?
What is the equation for flux (J) in the determination of diffusion coefficient?
What does passive diffusion continue as long as is maintained?
What does passive diffusion continue as long as is maintained?
What is the primary objective of dissolution rate studies?
What is the primary objective of dissolution rate studies?
Which factor can potentially increase the dissolution rate of poorly water-soluble drugs?
Which factor can potentially increase the dissolution rate of poorly water-soluble drugs?
What is the role of excipients in drug formulations?
What is the role of excipients in drug formulations?
What is the relationship between particle size and dissolution rate?
What is the relationship between particle size and dissolution rate?
What is the most important quality control test for many pharmaceutical preparations?
What is the most important quality control test for many pharmaceutical preparations?
What does the process of drug dissolution involve?
What does the process of drug dissolution involve?
What are in vitro tests used for in the pharmaceutical industry?
What are in vitro tests used for in the pharmaceutical industry?
What does the Biopharmaceutical Classification System (BCS) utilize for dissolution fluid?
What does the Biopharmaceutical Classification System (BCS) utilize for dissolution fluid?
What happens to the thickness of the diffusion layer over time?
What happens to the thickness of the diffusion layer over time?
What conditions are reported for the gastrointestinal (GI) tract after ingesting 250mL of water?
What conditions are reported for the gastrointestinal (GI) tract after ingesting 250mL of water?
What is the primary influence on the dissolution rate of drugs?
What is the primary influence on the dissolution rate of drugs?
What is the role of agitation in dissolution testing?
What is the role of agitation in dissolution testing?
What does Fick's First Law of Diffusion state?
What does Fick's First Law of Diffusion state?
What does the diffusion coefficient (D) represent?
What does the diffusion coefficient (D) represent?
What is the equation for flux (J) in the determination of diffusion coefficient?
What is the equation for flux (J) in the determination of diffusion coefficient?
What is the function of the diffusion coefficient related to?
What is the function of the diffusion coefficient related to?
What is the approximate fasting pH range in the duodenum of the small intestine?
What is the approximate fasting pH range in the duodenum of the small intestine?
What is the main buffer system in the small intestine?
What is the main buffer system in the small intestine?
What is the approximate bile salt/phospholipids ratio in the small intestine in the fasting state?
What is the approximate bile salt/phospholipids ratio in the small intestine in the fasting state?
What is the effective permeability (Peff) of the intestine for drug absorption?
What is the effective permeability (Peff) of the intestine for drug absorption?
What is the approximate transit time of drug absorption in the stomach in the fasting state?
What is the approximate transit time of drug absorption in the stomach in the fasting state?
Which BCS class of drugs may qualify for a waiver of in vivo bioavailability and bioequivalence studies?
Which BCS class of drugs may qualify for a waiver of in vivo bioavailability and bioequivalence studies?
What is the role of agitation in dissolution testing?
What is the role of agitation in dissolution testing?
What is the approximate surface area of the intestine needed for sufficient oral absorption?
What is the approximate surface area of the intestine needed for sufficient oral absorption?
What does the Biopharmaceutical Classification System (BCS) classify based on for oral drug absorption?
What does the Biopharmaceutical Classification System (BCS) classify based on for oral drug absorption?
What is the primary influence on the dissolution rate of drugs?
What is the primary influence on the dissolution rate of drugs?
What is the main factor for oral drug absorption according to the text?
What is the main factor for oral drug absorption according to the text?
What is the primary objective of dissolution rate studies?
What is the primary objective of dissolution rate studies?
What is the primary counterforce to diffusion that allows systems to reach homogeneity?
What is the primary counterforce to diffusion that allows systems to reach homogeneity?
What is the primary driving force for the transfer of one molecule across a distance?
What is the primary driving force for the transfer of one molecule across a distance?
What does Fick’s 2nd Law of Diffusion explain?
What does Fick’s 2nd Law of Diffusion explain?
What occurs when a solution is allowed to stand unagitated and the force of gravity acts?
What occurs when a solution is allowed to stand unagitated and the force of gravity acts?
What is the method used to determine the diffusion coefficient in a two-chamber vessel separated by a porous membrane?
What is the method used to determine the diffusion coefficient in a two-chamber vessel separated by a porous membrane?
What does passive diffusion continue as long as is maintained?
What does passive diffusion continue as long as is maintained?
What is the approximate transit time of drug absorption in the stomach in the fasting state?
What is the approximate transit time of drug absorption in the stomach in the fasting state?
What is the approximate fasting pH range in the duodenum of the small intestine?
What is the approximate fasting pH range in the duodenum of the small intestine?
What is the primary goal of establishing sink conditions in diffusion?
What is the primary goal of establishing sink conditions in diffusion?
What is the primary distinction between ultracentrifugation and centrifugation?
What is the primary distinction between ultracentrifugation and centrifugation?
What is the primary factor that can alter the distribution of solute molecules in space during sedimentation and ultracentrifugation?
What is the primary factor that can alter the distribution of solute molecules in space during sedimentation and ultracentrifugation?
What is the equation used to determine the flux (J) in the determination of the diffusion coefficient?
What is the equation used to determine the flux (J) in the determination of the diffusion coefficient?
What is the primary goal of dissolution rate studies?
What is the primary goal of dissolution rate studies?
What factors can influence the dissolution rate of drugs?
What factors can influence the dissolution rate of drugs?
What is the role of excipients in drug formulations?
What is the role of excipients in drug formulations?
What is the relationship between particle size and dissolution rate?
What is the relationship between particle size and dissolution rate?
What is the approximate pH range in the small intestine?
What is the approximate pH range in the small intestine?
What are dissolution tests carried out under?
What are dissolution tests carried out under?
What can bile salts do to enhance drug dissolution?
What can bile salts do to enhance drug dissolution?
What is the primary influence on the dissolution rate of drugs?
What is the primary influence on the dissolution rate of drugs?
What is the approximate volume of dissolution fluid utilized by the Biopharmaceutical Classification System (BCS)?
What is the approximate volume of dissolution fluid utilized by the Biopharmaceutical Classification System (BCS)?
What is the approximate transit time of drug absorption in the stomach in the fasting state?
What is the approximate transit time of drug absorption in the stomach in the fasting state?
What is the approximate transit time of drug absorption in the intestines in the fasting state?
What is the approximate transit time of drug absorption in the intestines in the fasting state?
What is the approximate bile salt/phospholipids ratio in the small intestine?
What is the approximate bile salt/phospholipids ratio in the small intestine?
Flashcards are hidden until you start studying
Study Notes
Drug Dissolution and Factors Affecting Dissolution Rate
- The process of drug dissolution is a kinetic process of solid particles going into solution, which is vital for determining the bioavailability of a drug in vivo.
- In vitro tests are used for drug quality control, with dissolution testing being the most important quality control test for many pharmaceutical preparations.
- Drug dissolution from a solid dosage form involves steps such as wetting, penetration of the solvent, swelling, disintegration, and dissolution of individual drug particles.
- Dissolution tests are carried out under simulated in vivo sink conditions with constant replacement of the dissolution medium and specific apparatuses and protocols as described by the USP.
- The primary objective of dissolution rate studies is the assessment of oral drug absorption under physiological conditions, and the Biopharmaceutical Classification System (BCS) utilizes 250mL of dissolution fluid.
- Physiological conditions in the gastrointestinal (GI) tract after ingesting 250mL of water are reported, including stomach and intestinal pH levels.
- Factors influencing drug dissolution rate include the diffusion layer thickness, agitation, pH, solubility, and the influence of excipients, surfactants, bile salts, particle size, and solid state properties.
- The thickness of the diffusion layer decreases over time, leading to an increase in the intrinsic dissolution rate, and the dissolution rate depends on the way solid particles are scattered over the bottom of the vessels.
- The pH of the dissolution medium, the solubility and dissolution of weak electrolytes and salts, and the influence of excipients can affect the dissolution rate of drugs.
- Excipients in drug formulations can increase or decrease the aqueous solubility of drugs, with different effects from substances such as lactose, starch, lubricants, and surfactants.
- Bile salts can form micelles, enhancing the solubility of lipophilic drugs and potentially increasing the dissolution rate of poorly water-soluble drugs.
- Particle size and surface area have a direct relationship with the dissolution rate, with micronization of particles increasing the dissolution rate and oral absorption.
Drug Dissolution and Factors Affecting Dissolution Rate
- The process of drug dissolution is a kinetic process of solid particles going into solution, which is vital for determining the bioavailability of a drug in vivo.
- In vitro tests are used for drug quality control, with dissolution testing being the most important quality control test for many pharmaceutical preparations.
- Drug dissolution from a solid dosage form involves steps such as wetting, penetration of the solvent, swelling, disintegration, and dissolution of individual drug particles.
- Dissolution tests are carried out under simulated in vivo sink conditions with constant replacement of the dissolution medium and specific apparatuses and protocols as described by the USP.
- The primary objective of dissolution rate studies is the assessment of oral drug absorption under physiological conditions, and the Biopharmaceutical Classification System (BCS) utilizes 250mL of dissolution fluid.
- Physiological conditions in the gastrointestinal (GI) tract after ingesting 250mL of water are reported, including stomach and intestinal pH levels.
- Factors influencing drug dissolution rate include the diffusion layer thickness, agitation, pH, solubility, and the influence of excipients, surfactants, bile salts, particle size, and solid state properties.
- The thickness of the diffusion layer decreases over time, leading to an increase in the intrinsic dissolution rate, and the dissolution rate depends on the way solid particles are scattered over the bottom of the vessels.
- The pH of the dissolution medium, the solubility and dissolution of weak electrolytes and salts, and the influence of excipients can affect the dissolution rate of drugs.
- Excipients in drug formulations can increase or decrease the aqueous solubility of drugs, with different effects from substances such as lactose, starch, lubricants, and surfactants.
- Bile salts can form micelles, enhancing the solubility of lipophilic drugs and potentially increasing the dissolution rate of poorly water-soluble drugs.
- Particle size and surface area have a direct relationship with the dissolution rate, with micronization of particles increasing the dissolution rate and oral absorption.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
