ABSTRACT
The previous investigation has proved that their existed pharmacokinetic difference between the different crystal forms of the polymorphic drugs after oral administration. However, no systemic investigations have been made on the change of this pharmacokinetic difference, resulted either from the physiological or from the pathological factors. In this paper, we used polymorphic nimodipine (Nim) as a model drug and investigated the effect of age difference (2- and 9-month old) on the pharmacokinetics after oral delivery in rats. As the results shown, for L-form of Nim (L-Nim), the AUCin 2-month-old rats was 343.68±47.15 ng·h/mL, which is 23.36% higher than that in 9-month-old rats. For H-form of Nim (H-Nim), the AUCin 2-month-old rats was 140.91±19.47 ng·h/mL, which is 54.64% higher than that in 9-month-old rats. The AUCratio between H-Nim and L-Nim was 2.44 in 2-month-old rats and 3.06 in 9-month-old rats. Since age difference could result in unparallelled change of the absorption and bioavailability of the polymorphic drugs, the results in this experiment are of value for further investigation of crystal form selection in clinical trials and rational clinical application of the polymorphic drugs.
ABSTRACT
Xanthone and its derivatives occupy a large part of the family of natural polyphenolic compounds with various biological and pharmacological activities.In recent years (from 2006 to 2011),it was reported that 127 xanthones were discovered from plants and fungi using various modem separation methods including silica gel/polyamide column chromatography,HPLC,high-speed counter-current chromatography,high-performance centrifugal partition chromatography,etc.Since total synthesis and structure modification for xanthone and its derivatives have been given attention worldwide,we introduced the synthetic methods of xanthone skeletons as well.Unfortunately,to date,there are still weaknesses in current methods of separation and synthesis,which need to be improved.This review,to a certain extent,provides necessary foundation for the further research and development of medicines containing xanthone and its derivatives.