What is the difference between bacteriostatic water and sterile water?
Both are sterile at the point of manufacture, but bacteriostatic water contains 0.9% benzyl alcohol as a preservative that inhibits bacterial growth after the vial is opened. Plain sterile water for injection is single-use: once you puncture the seal, it should be used immediately. Bacteriostatic water can safely be drawn from multiple times over 28 days if refrigerated.