Question

answer like it was pharmacology. do asap do all parts

4. A pharmacist prepares an intravenous solution of drug A. How many grams of dextrose does she need to add to the formulation? (2 sig fig for final answer) Rx. Drug A (E-value 0.36) Water qs. ad. 250ml Dextrose (E-value 0.18) qs. ad. Isotonic 5g a. What is the grams of sodium chloride equivalent of drug A? b. How many grams of sodium chloride would be in a pure solution of this volume? c. How many grams of sodium chloride would have to be added to make the drug A solution isotonic? d. How many grams of dextrose is equivalent to the grams of NaCl to be added?

Answer 1

Answer a.

the definition of E value (when preparing isotonic drug solutions, for determining  tonicity contribution of the drug ) is the number of grams of sodium chloride that would produce the same tonicity effect as 1 gram of the drug. This is achieved by using the NaCl equivalent or (E value) for the drug,.Here it is mentioned as 0.36.

Answer c

Because isotonic saline requires 0.9 g NaCl per 100 mL, 250 mL of isotonic saline will require 2.25 g (i.e., x = 2.25 g).

Formula

(100ml contain 0.9gm,

1ml contain 0.9/100gm

250 ml contain 0.9/100 mlx250ml=2.25gm

The 5gm or 500 mg of drug will correspond to 500 mg × 0.36 = 180 mg sodium chloride (i.e., y = 0.18 g). Thus, the weight of sodium chloride needed to make an isotonic solution = z = x - y = 2.25 g - 0.18 g = 2.07 g.