Chemical stability evaluation of Cassia fistula pod pulp extract by HPLC

Abstract

Cassia fistula Linn. (Fabaceae) is an ornamental plant widely grown in tropical and subtropical area. The ripe pod pulp has long been used as a traditional laxative drug due to anthraquinone glycosides and rhein is a major active constituent. This study was aimed to evaluate chemical stability of C. fistula pod pulp extracts which were storaged under the condition described in ASEAN guideline on stability of drug products1. The ripe pod pulp extract was prepared by decoction method. A validated HPLC was used for quantitative analysis of rhein content in the extracts. Three batches of the crude extract were stored for 6 months under accelerated (at 40°C) and real time storage conditions. The proposed HPLC method showed acceptable validation parameters and the content of rhein in the decoction extract was remained more than 96% (96.88% –99.62%) of the initial amount for all storage conditions. From the results, there was no significant change of the extracts and the acceptance criteria were met. Thus, the extract from C. fistula pod pulp had good stability and suitable to be further developed as an alternative laxative product.