Stability of hydroxyprogesterone caproate alone and in a compounded pharmaceutical product.

PURPOSE: The chemical stability of hydroxyprogesterone caproate in powder form and in a pharmaceutical formulation under different experimental conditions was evaluated. METHODS: Pure hydroxyprogesterone caproate was subjected to hydrolysis, photolysis, and thermal degradation. The content of hydroxyprogesterone caproate in pharmaceutical products was evaluated after using two different sterilization methods and after exposure to light. Hydroxyprogesterone caproate and its degradation products were analyzed using a validated reverse-phase high-performance liquid chromatographic method. Variables examined included specificity, accuracy, precision, linearity, theoretical plate numbers, signal:noise ratio, resolution between any two peaks, and relative standard deviation of the peak response. Statistical analysis was performed with Stata software, version 11 (StataCorp, College Station, TX). Mean values and standard deviations were calculated. The level of significance was set at p < 0.05. RESULTS: Components of hydroxyprogesterone caproate and organic impurities in pharmaceutical products were scanned with wide ultraviolet wavelength from 200 to 400 nm. In powder form, hydroxyprogesterone caproate was stable when exposed to high temperatures and light. Considerable degradation of hydroxyprogesterone caproate was observed in alkaline solution, with the major degradation product being hydroxyprogesterone. Much less degradation of hydroxyprogesterone caproate was observed in acidic conditions over 72 hours. The content of hydroxyprogesterone caproate in pharmaceutical products was not altered by the sterilization methods (filtration or heat sterilization) used and after exposure to light. CONCLUSION: Hydroxyprogesterone caproate in powder form and in a pharmaceutical formulation under different experimental conditions appeared to be fairly stable in the presence of strong acid, high temperatures, and light.