Question

1. )An aqueous drug solution was prepared in a hospital pharmacy and the shelf-life is known to be 7 days when the solution is stored at room temperature (25oC). By using rule of thumb, estimate the shelf-life when the solution is stored at 15oC (cold room)

(a) 17 days

(b) 14 day

(c) 5 days

(d) 18 days

(e) None of the above

2.) You have the assignment to prepare a water soluble injectable of atropine sulfate (pKa = 4.35). What would be the target pH in order for this drug to be 75% in its ionic form?

(a) 3.9

(b) 2.5

(c) 5.3

(d) 6.2

(e) None of the above

3.)Please determine the percent ionization for pentobarbital (acid, pKa = 8) injected into the bloodstream (pH 7.4).

(a) 99.9%

(b) 20.1%

(c) 30.5%

(d) 5.0%

(e) None of the above

4.)A solution of the weakly basic drug erythromycin (pKb = 5.2) is buffered to pH 7.4. What percentage of the drug will be ionized at this pH?

(a) 96.2%

(b) 20.1%

(c) 30.5%

(d) 5.0%

(e) None of the above

Answer 1