Stability of Clindamycin Phosphate in AutoDose Infusion System Bags

The physical and chemical stability of clindamycin phosphate 600mg/100mL and 1.2g/100mL admixed in 0.9% sodium chloride injection packaged in AutoDose Infusion System Bags was evaluated. Triplicate test samples were prepared by bringing the required amount of clindamycin phosphate injection to volume with 0.9% sodium chloride injection. A total of 100 mL of each of the test solutions was packaged in each of three ethylene vinyl acetate AutoDose bags designed for use in the AutoDose Infusion System. Samples were stored protected from light and were evaluated at appropriate intervals for up to 30 days at 4 deg C and up to 7 days at 23 deg C. Physical stability was assessed using a multistep evaluation procedure that included both turbidimetric and particulate measurement, as well as visual inspection. Chemical stability was assessed initially and at appropriate intervals during the study periods with stability-indicating high-performance liquid chromatographic anyalytical techinique based on the determination of drug concentrations. Throughout the study, the admixtures were clear and colorless when viewed in normal fluorescent room light and with a Tyndall beam. Measured turbidity and particulate content were low initially and exhibited little change throughout the study. The clindamycin phosphate samples exhibited no increase in measured particulates during the study period. High-performance liquid chromatographic analysis found little or no decomposition in the samples, and the analysis indicated that clindamycin phosphate in the test admixtures remained stable for 30 days at 4 deg C and for 7 days at 23 deg C. The clindamycin phosphate admixtures exhibited physical and chemical stability consistent with previous studies. The AutoDose Infusion System bags were not found to have an adverse effect on the physical and chemical stability of this drug.