Question

If the veterinarian asked you to reconstitute a bottle of 1 g per vial Cefazolin to contain 165mg/mL, how much sterile water would you add?

Answer 1

The sterile water required is 5.82 ml

Calculation

Per vial cefazolin contains 1g that is 1000 mg

To reconstitute the drug, 4.8 ml of sterile water gives 5ml of drug. And the concentration will be 200 mg per ml

To obtain 165 mg per ml concentration ,

To have 165 mg /ml , you need 6.06ml og drug (1000/165)

1 ml sterile water gives 1.04 ml of drug

To get 6.06 ml of drug , you need 5.82 ml of sterile water ( 6.06/1.04)