Relative bioavailability of gastrodin and parishin from extract and powder of Gastrodiae rhizoma in rat

The pharmacokinetic parameters of gastrodin and parishin in rats were obtained and the relative bio-availabilities of the two analytes in two dosage forms were calculated. The results indicated that GR powder at low dosage gained higher bio-availability, however, GR extract gained higher bio-availability at medium and high dosages.