q6(no cheatings) - sps

[ArchivalUser]

The greater proportion of the dose of a drug administered orally will be absorbed in the small intestine. However, on the assumption that passive transport of the nonionized form of a drug determines its rate of absorption, which of the following compounds will be absorbed to the least extent in the stomach?
A. Ampicillin (pKa = 2.5)
B. Aspirin (pKa = 3.0)
C. Warfarin (pKa = 5.0)
D. Phenobarbital (pKa = 7.4)
E. Propranolol (pKa = 9.4)

[ArchivalUser]

EE

[ArchivalUser]

E. pKa furthest from acid medium--> most ionized in acid medium.

[ArchivalUser]

e

[ArchivalUser]

EEEE

[ArchivalUser]

defnatly E

[ArchivalUser]

in the acid medium, the most non-ionized drug is pka 2.3 and least non-ionized is pka 9.4. so the least absorb is pka 9.4 drug.(?)

[ArchivalUser]

The answer is: E

At an acidic pH of about 3, of the drugs in question, all are weak acids except propranolol; therefore, propranolol has the greatest percentage of its molecules in the ionized form in the stomach. The higher the value of the pKa, the less ionized these substances are in the stomach.