生化学と分析生化学

概要

HPLC-UV/FD Methods for Scopoletin and Asiatic acid: Development, Validation and Application in WHO Recommended Stability Testing of Herbal Drug Products

Nancy Yogita Bansal and Gulshan Bansal

WHO recommended accelerated stability study was conducted on commercially available herbal products containing Shankhpushpi along with Bacopa monnieri (A) or Centella asiatica (B) at a temperature of 40 ± 2°C and 75 ± 5% RH for six months. Control sample of each product was stored at 4°C. Stability samples were withdrawn after 1, 3 and 6 months. Each control and stability sample was analysed for the content of scopoletin, asiatic acid and bacoside A by HPLC methods because such methods prove more selective, sensitive, efficient, reproducible, and accurate than spectroscopic and chemical methods. These methods also have advantages of sample handing, cost effectiveness and versatility in analyzing chemically diverse compounds over other methods like GSC and GLC. New methods developed and validated for scopoletin and asiatic acid were proved sufficiently precise, accurate and robust for analysis of scopoletin (1-500 ng/ml) and asiatic acid (10-1000 μg/ml). Bacoside A was not detected in any of the control samples of products A, indicating that B. monnieri is either absent in A or the content of Bacoside A is too low to be detectable. Content of scopoletin and asiatic acid was found to vary widely among different batches as well as products (scopoletin 165.78-206.15 ng/ml in A and 2.61-28.78 ng/ml in B, and asiatic acid 30.14-44.92 μg/ml in B), which indicate a probable variability in therapeutic efficacy of the products. The content of markers decreased significantly after 6 months of storage under accelerated conditions, which implies that therapeutic efficacy of the product may also decrease substantially with storage. These findings further suggest real time stability studies as per the WHO and ICH guidelines involving marker’s quantification and evaluation of therapeutic effects through appropriate in vitro/in vivo methods to establish actual shelf life of the products.