Quantitative analysis and formulation development of a traditional Thai antihypertensive herbal recipe

The health benefits of herbs and herbal products are gaining more attention in southeast Asia. The World Health Organization (WHO) has been supporting countries to promote application of traditional medicines so that this valuable resource is utilized safely and effectively. In Thailand, many traditional herbal recipes have been established since ancient times. Since then, they have been carefully modified, based on the wisdom of traditional Thai medicine practitioners. For this study, a traditional Thai antihypertensive herbal recipe (TTAH) was selected and studied in detail. According to WHO guidelines, both analysis of a sizeable chemical constituent, and formulation data of a product, are a requirement to support a clinical trial for an herbal recipe. Therefore, high-performance liquid chromatography–mass spectrometry (LC–MS) was used to investigate the chemical fingerprints, chemical constituents, and putative active ingredients of the TTAH. Eight chemical fingerprints were established. Metabolic profiling of 10 possible compounds was also identified and all were shown to be active pharmaceutical compounds. An attempt was also made to prepare a suitable formulation of the TTAH, to standardize the amount of active ingredients per dose, and to improve patient compliance. All evaluated parameters guided us to prepare the TTAH as a capsule. This informative data can be included in part of the chemistry–manufacturing–control guidance prior to phase 1/2 clinical trials.