Stability of bupivacaine hydrochloride in polypropylene syringes.

The stability of bupivacaine hydrochloride injection 1.25 mg/mL in 0.9% sodium chloride injection in polypropylene syringes was studied. Plastic syringes containing bupivacaine hydrochloride 1.25 mg/mL in 0.9% sodium chloride injection or 0.9% sodium chloride injection alone were stored at 3 or 25 degrees C. A glass vial containing the admixture was stored at 25 degrees C as a control. For each condition, triplicate samples were observed immediately and 5, 11, 15, and 32 days after preparation for precipitation and color change and analyzed for pH and for drug concentration by high-performance liquid chromatography. No change in bupivacaine concentration was observed during the 32-day study period, nor was there any change in color or pH nor any development of precipitation. Bupivacaine hydrochloride 1.25 mg/mL in 0.9% sodium chloride injection in polypropylene syringes was stable for up to 32 days when stored at 3 or 23 degrees C.