VALIDATION OF THE PROCEDURE FOR QUANTIFYING DITERPENE LACTONES AND STABILITY STUDY OF ANDROGRAPHIS PANICULATA HARD CAPSULES

Abstract

Andrographis paniculata (Burm.f.) Wall. ex Nees is a medicinal herb widely known for its potential therapeutic effects. The development of hard capsules containing Andrographis paniculata powder helps mask the bitter taste of the active ingredient while retaining its main effects. In addition, Andrographis paniculata has been shown to have few side effects on patients. However, the quality and stability of the formulation are a challenge for the formulation process. In this study, the quantitative procedure of the Andrographis paniculata extract and hard capsules was developed and validated to investigate the stability of the  Andrographis paniculata extract and the stability of the hard capsules with ingredients such as corn starch and stearic acid. The study was carried out at a laboratory of Tra Vinh University, from July 2025 to June 2026. The test results showed that the UV-Vis quantitative method met the requirements for quantifying diterpene lactones in  Andrographis paniculata. The dried extract contained 20.41% diterpene lactones, calculated as andrographolide equivalents, and yielded an estimated shelf life of 27 months with content retention of 93.7% under accelerated storage conditions, 45°C and 75% relative humidity for 6 months. The hard capsules were estimated to have a stability of 34 months, with diterpene lactone content of 94.0% after 6 months under the same storage conditions. Thus, cornstarch and stearic acid are suitable excipients for formulating hard capsules containing  Andrographis paniculata extract.