Bacteriostatic water is used for diluting or dissolving pharmacological preparations meant for intramuscular, subcutaneous, or intravenous injection. Bacteriostatic water for injection is only for parenteral use and must be combined with pharmaceuticals that require dilution or dissolving prior to administration. Multi-dose vials enable multiple withdrawals for use with numerous preparations. Once the vial has been opened, it is recommended to use within 4 weeks (28 days).