title: Stability indicating studies on NMITLI 118RT+ (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-118RT+ is a candidate drug under a Council of Scientific and Industrial Research (CSIR) networking project. It is a chemotype of W. somnifera's root extract, which has been used for the present study.
  
  
  OBJECTIVE
  The present investigation aims to develop and validate a simple isocratic reverse phase-high performance liquid chromatography (RP-HPLC) system for the detection and estimation of Withanolide A (marker compound) and its analytical application for stability indicating studies on NMITLI-118RT+.
  
  
  METHODS
  A validated RP-HPLC method for Withanolide A was established on a Waters HPLC system and the same was used on NMITLI-118RT+ for quantification and fingerprinting purposes, and for establishing forced degradation, isothermal stress tests, and drug-excipient testing protocols as per International Conference on Harmonization (ICH) guidelines.
  
  
  RESULTS
  A validated method was established, which could detect the marker at a retention time of around 6.3 minutes, with a linearity range of 2-100 μg/mL, by varying the amounts of the said marker, which were estimated in four different batches of NMITLI-118RT+. Photostability as per ICH guidelines suggested a slight loss of the active constituent and maximum degradation was afforded with alkali followed by acid, and then peroxide, in the forced degradation studies. In the drug-excipient studies, the maximum amount of active constituent could be detected in the samples with ethyl cellulose and the least with hydroxy propyl cellulose.
  
  
  CONCLUSIONS
  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-118RT+.
authors.affiliation: Division of Pharmaceutics, Central Drug Research Institute, Lucknow, Uttar Pradesh, India.
authors.forename: Hafsa
authors.initials: H
authors.lastname: Ahmad
authors.affiliation: Division of Pharmaceutics, Central Drug Research Institute, Lucknow, Uttar Pradesh, India.
authors.forename: Kiran
authors.initials: K
authors.lastname: Khandelwal
authors.affiliation: Division of Pharmaceutics, Central Drug Research Institute, Lucknow, Uttar Pradesh, India.
authors.forename: Shakti Deep
authors.initials: SD
authors.lastname: Pachauri
authors.affiliation: Department of Metabolic and Structural Biology, Central Institute of Medicinal and Aromatic Plants, Lucknow, Uttar Pradesh, India.
authors.forename: Rajender Singh
authors.initials: RS
authors.lastname: Sanghwan
authors.affiliation: Division of Pharmaceutics, Central Drug Research Institute, Lucknow, Uttar Pradesh, India.
authors.forename: Anil Kumar
authors.initials: AK
authors.lastname: Dwivedi
keywords: Ashwagandha; Withanolide A; excipients; forced degradation; photostability