10ml (5 x 2ml vials) Bacteriostatic water for injection, also known as bac static water, is sterile water that contains small amounts of benzyl alcohol to preserve the water. The combination of sterile water and benzyl alcohol allows for repeated withdrawals to be made from a single vial. Bacteriostatic water UK has a shelf life of 28 days and should be discarded after this time period. Normal sterile water for sale for injection does not contain a bacteriostatic agent and must be discarded after each use.
Bacteriostatic water 10ml can be used to dissolve peptides and other formulations that need to be diluted in solution prior to injecting. The water should be withdrawn from the vial directly, by puncturing with a clean needle. Bac water UK has a pH around 5.7 and is suitable water for injection.