Simplified process of candidate certified reference material development for the analysis of Andrographis paniculata derived therapeutics

•A certified reference material (CRM) of andrographolide was developed first time.•Developed novel method to produce RM of andrographolide (>99%) from A. paniculata.•Purity was established by HPLC, mass balance and DSC methods.•Developed CRM was stable for one month at room temperature and 12 month at −20 °C.•Developed reference material fulfills the technical requirement of ISO 17025:2017.