A list of interview questions and answers for pharma jobs
(Biopharmaceutics Part)
Q1. What are the Pharmacokinetics parameters?
- Absorption: Absorption rate constant, Bioavailability.
- Distribution: Apparent volume of distribution, Unbound fraction.
- Elimination: Rate of elimination, Clearance, Renal clearance, Metabolic clearance, Biological half-life.
Q2. What do you mean by Cmax and Tmax?
- Cmax: maximum serum concentration that a drug achieves in a specified compartment.
- Tmax: the time at which Cmax is observed.
Q3. In which Cmax and Tmax depend on?
Cmax and Tmax depend on the extent and the rate of drug absorption and the disposition profile of the drug.
Q4. Which excipients may affect on drug absorption?
Sugar-alcohols, (e.g., mannitol, Sorbitol) and surfactants, (e.g., sodium lauryl sulfate).
Q5. How can risk of excipients on absorption is measured?
- The amount of excipient used,
- The mechanism by which the excipient may affect absorption,
- Absorption properties (rate, extent and mechanism of absorption) of the drug substance.
Q6. Which drug substances are more susceptible to the effects of excipients?
BCS Class III drug substances are considered to be more susceptible to the effects of excipients.
Q7. Why BCS Class III is more susceptible?
These drugs are poorly permeable and may have site-specific absorption, so there are a greater number of mechanisms through which excipients can affect their absorption than for BCS Class I drugs.
Q8. Which steps should be taken for BCS Class III drug substances?
For BCS Class III drugs, all of the excipients should be qualitatively the same and quantitatively similar (except for film coating materials or capsule shell excipients).
Q9. In which BCS Class II drugs solubility depends on?
In general, dissolution of BCS class II drugs is dependent on a wide variety of physiological factors. pH, ionic strength, and buffer capacity are three major characteristics of the GI fluids that can affect the rate of drug release.
Q10. Which steps can be taken for enhancing the dissolution and absorption of class II drugs?
- Buffering the pH of microenvironment
- Use of salts of weak acids and weak bases
- Use of solvates and hydrates
- Use of selected polymorphic forms
- Complexation
- Prodrug approach
- Use of surfactants etc.
Q11. Which classes of BCS are not suitable or problematic for Control release drug delivery?
- BCS class III drugs are problematic for controlled release development.
- BCS class IV drugs are generally not suitable for oral drug delivery or else some special drug delivery technologies such as Nano-suspensions will be needed.
Q12. What is Bioequivalence?
Bioequivalence is a term in pharmacokinetics used to assess the expected in vivo biological equivalence of two proprietary preparations of drug.
Q13. When two products are said to be Bioequivalent?
Two products are said to be bioequivalent when there have no significant difference in rate and extent of absorption between the products.
Q14. What is Biowaiver?
A Biowaiver means that in vivo bioavailability and/or bioequivalence studies may be waived (not considered necessary for product approval).
Q15. Which drugs are applicable for Biowaiver?
Biowaiver is applicable for BCS class I & III (with special consideration) drugs.
Q16. What is IVIVC?
An in-vitro in-vivo correlation is “a predictive mathematical model describing the relationship between an in-vitro property of a dosage form and an in-vivo response”.
Q17. How can overcome the BCS class IV material problems?
BCS class IV drugs are generally not suitable for oral drug delivery or else some special drug delivery technologies such as Nano-suspensions will be needed.
Q18. What do you mean by Biosimilar (drug)?
A biosimilar is a biologic medical product that is almost an identical copy of an original product with the same active substance that is manufactured by different company.
Q19. How can ensure that the bioavailability of the drug is not limited by dissolution?
The BCS suggests that for high solubility, high permeability (class 1) drugs and in some instances for high solubility, low permeability (class 3) drugs, 85% dissolution in 0.1N HCl in 15 minutes can ensure that the bioavailability of the drug is not limited by dissolution.
Q20. Which is identified by PK and PD parameters?
- PK describing the relationship between dose, systemic drug concentration and time.
- PD describing the relation between systemic drug concentration and the effect vs. time profile.