Stability Indicating Method for Known and Unknown Impurities Profiling for Cholecalciferol Tablets

The main objective of this research work was to develop and validate, a new gradient, highly sensitive, specific and stability indicating Reverse Phase HPLC method for quantitative determination of known, unknown impurities and degradant impurities profiling for Cholecalciferol tablets. No Pharmacopoeial method is available to quantify known, unknown impurities and degradants profiling for Cholecalciferol tablets. The impurities were separated on the Hypersil BDS column (150 mm x 4.6mm, 3 mu m) with a mobile phase of mixture of Trifluoroacetic acid buffer and acetonitrile with flow rate of 1.5 mL minute(-1). The column compartment was maintained at 40 degrees C and the detection wavelength was at 265nm. Cholecalciferol, its known impurity and unknown impurities have been well resolved from each other. Recovery of the known and unknown impurities found between 80% to 120% as per ICH guideline. Method found linearity over the working concentration range with acceptance criteria of correlation coefficient greater than 0.99. Method precision and intermediate precision results found with percentage relative standard deviation of impurity content less than 10% for replicated analysis of test samples. A stress study was conducted with a drug product that was exposed to different conditions of acid, base, oxidation, heat, humidity and photolytic degradation. Cholecalciferol was found to degrade significantly under Photolytic, Thermal and Alkaline stress conditions. The degradation products were well resolved from Cholecalciferol and its impurities. For each stress condition, peak purity of Cholecalciferol was assessed using the Photodiode Array detector and found homogeneous in nature. The mass balance for stress study was found in between 95% and 105%. Thus, proving the stability indicating nature of the analytical method. The developed method was validated as per ICH guidelines. The method found accurate, precise, linear, robust, rugged, specific and stability indicating in nature.