Stability of preoperative cataract surgery gel in polycarbonate syringes

The stability of preoperative cataract surgery gel packaged in 1-mL polycarbonate syringes, stored protected from light under controlled temperatures for a period of 60 days, was studied. Preoperative cataract surgery gel is a mixture of cyclopentolate hydrochloride 0.51 mg/mL, phenylephrine hydrochloride 5.1 mg/mL, and tropicamide 0.51/mL in preservative-free lidocaine hydrochloride 2% gel. Stability was defined as the maintenance of initial physical and chemical charactereistics during storage under controlled ambient (25 deg C/60% relative humitidty) or refrigerated (2 deg C to 4 deg C) conditions. Evaluation parameters were appearance, pH,sterility, endotoxin level, and potency of each active ingredient. The specificity and stability-indicating characteristics of an assay method using high-performance liquid chromatography were validated through forced degradation studies. Samples were tested at predefined time intervals over a period of 60 days. Preoperative cataract surgery gel maintained the appearance of a clear and colorless gel, with pH values ranging form 5.58 to 5.77 throughout the study period. The average initial drug concentrations for cyclopentolate hydrochloride, phenylephrine hydrochloride, lidocaine hydrochloride, and tropicamide were determined to be within +/- 10% of their label concentrations. Recovery of the active ingredients at subsequent time points was within +/- 10% of their initial concentrations, and chromatographic profile for all tested samples exhibited no changes in stability of the active ingredients. The ophthalmic gel tested sterile and had no detectable endotoxin during the 60-day study period. Preoperative cataract surgery gel packaged in polycarbonate syringes and stored protected from light is stable through 60 days at both controlled ambient and refrigerated conditions.