Ginsenoside Re And Its Solid Dispersion Property Pharmacokinetic Studies

Colorimetric method was developed for the determination of Ginsenoside Re concentration in vitro. The calibration curve was linear in the range from 4.74-142.2 #g /ml, with r =0.9997. The method showed good precision and the method recovery of Re was 100. 1 %. the relative standard deviation for within-day and between-day was less than 3%. A HPLC method was established for the determination of Re concentration in biological samples. Puerarin was used as the internal standard , biological samples can be well purified after extraction with n-butanol. The calibration curve was linear in the range from 1 # g /ml to 1 00 # g /ml, with r =0.9992, the detection limit of this method was 0.3 # g /ml. The method indicated good precision and the method recovery of Re from biological samples was 98.7~102.3%. The extraction recovery of Ginsenoside Re was 80.9%, the relative standard deviation for within-day and between-day were 1.54-4.56%. Also a method was used for the determination of Ginsenoside Re concentration in intestinal solution by spectroscopy. The calibration curve of phenol-red was linear in the range from 10 to 80 # g-ml-1, with r =0.9997, 0.9994, respectively. The calibration curve of Re was linear in the range from 3.2 to 120# g-ml-1, with r =0.9995. The method showed good precision and the method recovery of Re was 97.5 ~ 102. 5%. The relative standard deviation for within-day and between-day were 1. 78 ~ 3. 86%.In this paper we prepared Ginsenoside Re solid dispersion and measured its dissolution in vitro. Ginsenoside Re solid dispersions were obtained with PEG-6000, PVP and poloxamerl88 as carriers by meltingand melting-solvent methods. Powder X-ray diffraction were used to determine the status of drug in carriers, and the dissolution characteristics in vitro were studied in distilled water. In poloxamerl88-ginsenoside Re solid dispersions most of ginsenoside Re was amorphous. Poloxamerl88 is a very useful carrier in improving the solubility and dissolution of ginsenoside Re The paper improved intestinal absorption experiments of rat were used to study the absorption of Re and Re-poloxamerl88 solid dispersion. It was found that there was no marked difference in absorptive rate in rats without or with bile duct-ligated.This paper reported the pharmacokinetics and bioavailability of Re in Rat. The experimental results showed that the concentration-time of Ginsenoside Re in Rats after iv. of 20, 30 and 40 mg/kg were shown to fit a two-compartment model. After oral administration, the concentration-time curve of Ginsenoside Re in Rats fit one-compartment model. After iv. and oral administration, the bioavailability of Re is 7.35%, For Re-poloximer I88dispersion, the absolute bioavailability is 16.1%, relative bioavailability is 218.9%.