Docsity
Docsity
Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity

Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips
Guidelines and tips
Sell on Docsity
Sell on Docsity
Docsity AI
Docsity AI
Log inSign up

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search for your university

Find the specific documents for your university's exams

Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents
download point icon20 Points

For each uploaded document

Answer questions
download point icon5 Points

For each given answer (max 1 per day)

All the ways to get free points
Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

Drug Dissolution Study Guide: Key Concepts and Equations, Exams of Advanced Education

Princeton UniversityAdvanced Education

This study guide provides a comprehensive overview of drug dissolution, a critical process in drug absorption and bioavailability. It covers key concepts such as the definition of dissolution, equilibrium conditions, interfacial reactions, and the forces involved. The guide details the steps a solid drug undergoes to reach systemic circulation, including disintegration, deaggregation, dissolution, and absorption. It explains the noyes-whitney equation and its components, such as diffusion coefficient, surface area, and concentration gradient, and how these factors influence the dissolution rate. The guide also addresses sink conditions and the impact of agitation on dissolution, offering a thorough understanding of the principles governing drug dissolution for pharmaceutical science students.

Typology: Exams

2024/2025

Available from 07/16/2025

Prof-Cornel
Prof-Cornel 🇺🇸

4.9K documents

1 / 3

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
PHRM 4200- Dissolution Exam
Study Guide
What is dissolution? - Answer the process of dissolving drug from a solid state into
solution
When is dissolution in equilibrium? - Answer the solid drug and the drug in solution are
at equilibrium when the solution is saturated (at a given temp, pH, pressure)
interfacial reaction - Answer where the bulk solid drug meets the solvent; the solvent
attacks the solute particles to release them from the bulk drug (adhesion)
Where in the dissolution diagram are there cohesive forces? - Answer in the bulk drug
and in the bulk solution
Where in the dissolution diagram are there adhesive forces? - Answer where the drug
and solvent particles meet
What process is the opposite of dissolution? - Answer precipitation
What are the 4 steps of how a solid drug gets to systemic circulation? - Answer -
disintegration (to granules)
- deaggregation (to powder)
- dissolution (to solution)
- absorption
What happens in the process of disintegration? - Answer the tablet is disintegrated into
granules
What happens in the process of deaggregation? - Answer granules of drug are
deaggregated into powder
What is the difference between tablets and capsules in terms of the process to systemic
circulation? - Answer tablets go through all 4 steps, capsules are already in powder
form so only dissolution and absorption
the rate of dissolution is a function of ___ - Answer diffusion (determined by the
movement of dissolved drug from the solid surface into the bulk solvent)
What is the diffusional region? - Answer the area where bulk drug is moved away
towards bulk solution
What is the stagnant diffusion layer? - Answer the area where bulk drug and bulk solvent
meet and interact for the first time
pf3

Partial preview of the text

Download Drug Dissolution Study Guide: Key Concepts and Equations and more Exams Advanced Education in PDF only on Docsity!

PHRM 4200- Dissolution Exam

Study Guide

What is dissolution? - Answer the process of dissolving drug from a solid state into solution When is dissolution in equilibrium? - Answer the solid drug and the drug in solution are at equilibrium when the solution is saturated (at a given temp, pH, pressure) interfacial reaction - Answer where the bulk solid drug meets the solvent; the solvent attacks the solute particles to release them from the bulk drug (adhesion) Where in the dissolution diagram are there cohesive forces? - Answer in the bulk drug and in the bulk solution Where in the dissolution diagram are there adhesive forces? - Answer where the drug and solvent particles meet What process is the opposite of dissolution? - Answer precipitation What are the 4 steps of how a solid drug gets to systemic circulation? - Answer - disintegration (to granules)

  • deaggregation (to powder)
  • dissolution (to solution)
  • absorption What happens in the process of disintegration? - Answer the tablet is disintegrated into granules What happens in the process of deaggregation? - Answer granules of drug are deaggregated into powder What is the difference between tablets and capsules in terms of the process to systemic circulation? - Answer tablets go through all 4 steps, capsules are already in powder form so only dissolution and absorption the rate of dissolution is a function of ___ - Answer diffusion (determined by the movement of dissolved drug from the solid surface into the bulk solvent) What is the diffusional region? - Answer the area where bulk drug is moved away towards bulk solution What is the stagnant diffusion layer? - Answer the area where bulk drug and bulk solvent meet and interact for the first time

the distance the drug has to move to reach the bulk solvent (h) h - Answer the thickness of the stagnant diffusion layer

  • decreased with agitation Where is the solution saturated in dissolution? - Answer at the interface, where bulk drug meets solvent Cs - Answer solubility of drug (at the solid - stagnant layer interface)
  • affected by temp, crystal structure, pH, affinities (IMFs) C - Answer concentration of drug in bulk solvent at any given time (t) -> directly related to volume of solvent t - Answer time What happens to drug concentration as you move through the stagnant diffusion layer? - Answer high at the interface, and lower when it reaches the bulk solvent; beyond that, it is uniformly mixed What is the Noyes-Whitney equation? - Answer dM/dt = DS/h (Cs-C) dM/dt - Answer rate of dissolution (mg/s, mol/hr, etc.) M - Answer mass of solute S - Answer surface area of the exposed solid (cm^2,etc.) particle size D - Answer diffusion coefficient of the solute in solution (cm^2/sec) How does the difference between Cs and C affect the dissolution rate? - Answer represents the concentration gradient; we want the solubility to be much greater than the concentration (large difference) How does h affect the rate of dissolution? - Answer basically the distance the drug has to move to be in solution; want it to be small (denominator) How does D affect the rate of dissolution? - Answer basically the opposite of resistance to movement; want it to be large (numerator) How does S affect the rate of dissolution? - Answer the surface area of exposed solid; want it to be large so that the drug makes more contact with the solution (numerator)
  • inversely proportional to particle size Why should you take certain drugs with a full glass of water? - Answer more solvent for the drug to dissolve -> higher dissolution rate (lower C)