There are two dosage forms usually used in clinical Chinese medicine, i.e. traditional decoction and herbal concentrate. Only the herbal concentrate is covered by health insurance. However, it seems that there were no studies to evaluate the bioequivalence between herbal concentrate and traditional decoction. In order to provide the data base for clinical application, this study attempted to assess the bioequivalence between herbal concentrate and traditional decoction. At least six commercial herbal concentrates will be purchased from the market. The contents of the antioxidant flavonoids (naringin, narirutin, naringenin, hesperidin and hesperetin) will be determined by HPLC methods established in our laboratory. The brand containing the highest content of marker constituents will be given to 8-10 healthy males. The administrations of traditional decoction and commercial herbal concentrate will be carried out in a crossover design.Urine will be collected in eight intervals until 24 hr. The major metabolites of the marker flavonoids will be determined by HPLC after enzymatic hydrolysis. The urinary data will be used to calculate the pharmacokinetics of the flavonoids and to compare the absorption rate between two dosage forms. Hopefully, the results of this project could provide useful information for clinical application of Chinese medicine. Moreover, it could also raise the necessity for the research and inprovement of manufactuing of Chinese herbal concentrates.
