ABSORPTION OF DRUGS GPAT MCQs Part – 1

TOP 10 MCQ

1. Which one of the following statements holds true for Passive Diffusion [GPAT-2022]
(a) Greater the area and greater the thickness, faster is the diffusion
(b) Rate of drug transfer is directly proportional to the concentration gradient between GI fluids and the blood compartment
(c) Rate of transfer of ionised drug species is 3–4 times the rate for unionised drug species
(d) Greater the membrane/water partition coefficient of drug, slower is the absorption

2. Decrease in effective surface area available to the dissolution medium leading to a fall in the dissolution rate, may happen due to which one of the following reasons [GPAT-2022]
(a) Addition of cyclodextrin
(b) Addition of surfactant to increase the surface tension
(c) Addition of hydrophilic diluent
(d) Surface charges due to extreme particle size reduction

3. For very weak acidic drugs, with pKa > 8 [GPAT-2021]
(a) They are unionized at all pH, hence absorption is rapid and independent of GI pH
(b) They are affected by changes in pH, hence absorption is pH dependent
(c) They are ionized in the entire pH range of GIT, hence poorly absorbed from GIT
(d) They are ionized in the gastric pH, hence better absorbed from the stomach

4. The complexation of Quinidine with hexyl is an example of absorption by [GPAT-2020]
(a) Convective transport
(b) Facilitated transport
(c) Pinocytosis
(d) Ion pair transport

5. Fraction of administered dose (which may be in form of an ester of salt) of active drug is termed as [GPAT-2020]
(a) Activity factor
(b) Formulation factor
(c) Intrinsic factor
(d) Salt factor

6. Volume of blood that flows per unit time per unit volume of the tissue is [GPAT-2019]
(a) Residence time
(b) Elimination rate
(c) Gastric emptying rate
(d) Perfusion rate

7. In plasma, Phenobarbital is present as ionized and unionized forms in equal amount because [GPAT-2018]
(a) It is weakly acidic drug
(b) It is weakly basic drug
(c) pH of plasma is 6.8
(d) pKa of the phenobarbital is 7.4

8. Very weak bases having pKa < 5 [GPAT-2018]
(a) Are ionized in the entire pH range of GIT
(b) Absorbed only in stomach
(c) Are unionized at all pH values
(d) None of these

9. If the pKa of lidocaine is 7.9 and pH of the infected tissue is 8.9, the fraction of drug in the ionized form will be [GATE-2002, GPAT-2017]
(a) 10%
(b) 1%
(c) 90%
(d) 99%

10. Hixson–Crowell’s cube root law of dissolution states that [GPAT-2017]
(a) There is a change in particle size and surface area during dissolution of drug
(b) Dissolution process is controlled by diffusion of molecules/ions
(c) High free energy of activation is required for solution
(d) Renewal of surface fluid layer around drug particle

ANSWER KEY