Abstract
The purpose of the present study was to develop stability indicating HPLC method for simultaneous estimation of Nicotinamide and Salicylic acid and to validate developed method in accordance with ICH guidelines. Stability indicating reverse phase high performance liquid chromatography method was developed for Nicotinamide and Salicylic acid. Various trials with aqueous phase and organic phase were performed and mobile phase was optimized. The separation was achieved using Chromatopak C-18 (250mm x 4.6 mm, 5 µm) column, mobile phase containing Methanol and Water (0.1% TEA and 0.15 gm Hexane sulphonic acid and pH 3.0 adjusted with Glacial acetic acid) in the ratio of (40:60 v/v), at a flow rate of 1.0 ml/min. The retention time for Nicotinamide and Salicylic acid was 4.343 min and 17.673 min respectively. Forced degradation study was performed by applying stress conditions like acid hydrolysis, alkali hydrolysis, and neutral hydrolysis, and oxidation, thermal and photolytic degradation. %degradation was calculated with respect to drugs and specificity.LC method was validated by ICH Q2 (R1) guideline. The linearity was observed in the concentration range of 225-315 μg/ml for Nicotinamide and 75-105 μg/ml for Salicylic acid. The correlation coefficient was found to be 0.9971 and 0.9985 for Nicotinamide and Salicylic acid respectively. Degradation in all conditions was found to be 10 -20%. The method specifically estimates both the drugs in the presence of all the degradant generated during forced degradation study. The developed method was specific and precise and can be used for simultaneous estimation of Nicotinamide and Salicylic acid.

Key words: Nicotinamide, Salicylic acid, RP-HPLC method, forced degradation