Stability of pibenzimol hydrochloride in commonly used infusion solutions and after filtration

The stability of pibenzimol hydrochloride was evaluated after reconstitution, after addition to several intravenous fluids, and after filtration. Vials containing pibenzimol hydrochloride 50 mg were reconstituted with 2.5 mL of 0.9% sodium chloride injection to 20 mg/mL. For determination of drug stability in intravenous fluids, vial contents were further diluted to 0.15 mg/mL by injection into glass containers and polyvinyl chloride (PVC) bags containing 250 mL of 5% dextrose injection, 0.9% sodium chloride injection, or lactated Ringer's injection. Pibenzimol concentrations were determined immediately after preparation and at various intervals after storage at 4-6 degrees C or 25 degrees C by means of a stability-indicating, high-performance liquid chromatographic technique. Vial contents were inspected visually for color changes, and pH was measured. Determinations were also made of the stability of pibenzimol 0.15 mg/mL in 0.9% sodium chloride injection after simulated infusions using a 0.22-micron filter set at 25 degrees C. All study solutions and admixtures retained more than 90% of the initial pibenzimol concentration. The greatest loss of drug (6-7%) occurred after 24 hours in lactated Ringer's injection in both glass and PVC containers and in 0.9% sodium chloride injection in PVC bags. No drug loss occurred as a result of filtration. Reconstituted pibenzimol hydrochloride and admixtures of pibenzimol in 5% dextrose injection, 0.9% sodium chloride injection, or lactated Ringer's injection in glass or PVC containers are stable for at least 24 hours at 25 degrees C. Filtration has no effect on stability.