Drug Biotechnology Interview Questions and Answers on “Drug Absorption – Influencing Factors and Bioavailability”.
1. Which one of these is a physicochemical property of Drug substance?
a) Drug solubility
b) Disintegration time
c) Age of patient
d) Dissolution time
Answer: a
Clarification: Pharmaceutical factors include factors relating to the physicochemical properties of the drug and dosage. The physicochemical property includes drug solubility, dissolution rate, particle size, etc.
2. Which one of these does not come under a physicochemical property of drugs?
a) Drug solubility
b) Disintegration time
c) Dissolution rate
d) Drug stability
Answer: b
Clarification: Physicochemical properties of drug substances include drug solubility, dissolution rate, particle size, effective surface area, polymorphism, etc. Dissolution time comes under Dosage form characteristics and pharmaceutic ingredients.
3. In the sequence of events in the drug absorption from orally administered solid dosage, which one comes at first?
a) Disintegration
b) Disaggregation
c) Dissolution
d) Absorption
Answer: a
Clarification: The solid dosage form at first disintegrate into smaller granules or aggregates. Those are then deaggregated to form fine particles. In dissolution, the drug is in the solution form and then it gets absorbed.
4. Which one is the correct sequence for drug absorption through the oral route?
a) Absorption – Dissolution – Disintegration – Deaggregation
b) Disintegration – Dissolution – Deaggregation – Absorption
c) Disintegration – Deaggregation – Dissolution – Absorption
d) Disintegration – Deaggregation – Absorption – Dissolution
Answer: c
Clarification: Disintegration of the drug and then Deaggregation and subsequent release of a drug. Followed by the dissolution of the drug in aqueous fluids at the absorption site and the movement of the dissolved drug through the gastrointestinal membrane into the systemic circulation.
5. Patient-related factors of drug absorption do not deal with which one of these?
a) Age
b) Gastric Emptying time
c) Intestinal transit time
d) Pharmaceutic ingredients
Answer: d
Clarification: Patient-related factors include factors related to anatomy, physiology, and pathologic characteristic of a patient. This includes age, Gastric Emptying time, Intestinal transit time, gastrointestinal pH, Disease states, Blood flow, etc.
6. The rate at which drug reaches the systemic circulation is determined by the slowest of the various steps involved in the sequence. This is known as ____________
a) Disintegration time
b) Dissolution time
c) Rate limiting step
d) Gastric Emptying time
Answer: c
Clarification: The rate at which drug reaches the systemic circulation is determined by the slowest of the various steps involved in the sequence. Such a step is known as the rate-limiting. Disintegration time is the time required for the drug to be broken down into smaller particles or aggregates. Dissolution time is the time required for all the drug disintegrated particle to dissolve in the fluid. Gastric emptying time is the emptying time of the stomach.
7. Diffusion coefficient of drug D, Greater the value faster us the dissolution.
a) True
b) False
Answer: a
Clarification: Greater the value faster is the dissolution of the drug into solution. Diffusion decreases as the viscosity of the dissolution medium increase.
8. Greater the surface area lesser is the dissolution.
a) True
b) False
Answer: b
Clarification: Greater the surface area greater is the dissolution. Thus micronization of the drug is preferred. Dissolution can be increased by micronization.