Question

Penicillin G potassium 5000 units/mL

Isotonic sodium chloride solution ad 15 mL

Using soluble penicillin tablets, each containing 200,000 units of crystalline penicillin G potassium, explain how you would obtain the penicillin G potassium needed in compounding the prescription.

Answer 1

To prepare 15 mL of a 5000 units/mL penicillin G potassium solution, calculate the total units needed (75,000 units), and then determine the fraction of a 200,000-unit penicillin tablet required. Dissolve the correct tablet portion in isotonic sodium chloride solution.

Step-by-step explanation:

To compound the prescription requiring 5000 units/mL of Penicillin G potassium in a 15 mL isotonic sodium chloride solution, you would first need to determine how many units of penicillin are required for the entire solution. The total amount needed is 5000 units/mL × 15 mL, which equals 75,000 units. Since each tablet contains 200,000 units, you would divide the total units needed by the number of units per tablet to find out how many tablets to use: 75,000 units ÷ 200,000 units/tablet.

Therefore, you would use a portion of a tablet to obtain the desired concentration. After calculating the fraction of the tablet needed, you would dissolve the appropriate fragment of the soluble penicillin tablet in the 15 mL of isotonic sodium chloride solution to achieve a final concentration of 5000 units/mL.