Stability Indicating Studies on NMITLI 118R (Standardized Extract Of Withania somnifera Dunal.)

Abstract

Background: Withania somnifera Dunal (Ashwagandha) is an Indian medicinal plant of great medicinal value; used in many clinically proven conditions. NMITLI-118R a candidate drug under a CSIR networking project is a chemotype of W. somnifera’s root extract which has been used for the present study. Objectives: The present investigation aimed at development and validation of a simple isocratic RP-HPLC system for detection and estimation of Withanolide A (marker compound) and its analytical application for stability indicating studies on NMITLI-118R. Material and methods: A validated RP-HPLC method for Withanolide A was established on Waters HPLC system and the same was used on NMITLI-118R for quantification and fingerprinting purposes and establishing forced degradation, isothermal stress tests, drug-excipient testing protocols as per ICH guidelines. Results: A validated method was established which could detect the marker at a retention time of around 6.3 mins with a linearity range of 2-100 µg/mL, varying amounts of the said marker were estimated in 4 different batches of NMITLI-118R. Photostability as per ICH guidelines suggested slight loss of active constituent and maximum degradation was afforded with alkali followed by acid and then peroxide in the forced degradation studies. Maximum amount of active constituent could be detected in samples with ethyl cellulose and the least with hydroxy propyl cellulose in the drug-excipient studies. Conclusion: The method developed here was simple and rapid. The various stability indicating studies carried out in the present investigation would be useful for formulation development and were suggestive of deciding the recommended storage conditions for NMITLI-118R.