The Study Of Transdermal Absorption Of Ginsenoside-Rd

Objective:To evaluate the penetration enhancing effect of various penetration enhancers on the in vitro transdermal absorption of ginsenoside-Rd and select the one with the best enhancing quality to prepare ginsenoside-Rd patches. Besides, to investigate the in vivo transdermal absoption by studying the anti-inflammatory effect of ginsenoside-Rd administered transdermally.Methods:Experiments were carried on penetration experimental facility using modified Franz-type diffusion cell with excised mice skin as permeation barrier and saline as receptor solution. The content of ginsenoside-Rd in receptor solution at different time was determined by High Performance Liquid Chromatography (HPLC), which was used to investigate the effect of various penetration enhancers on the transdermal absorption of ginsenoside-Rd. After that ginsenoside-Rd patches were prepared with pressure sensitive adhesive (polyacrylate EUDRAGIT E100), the best penetration enhancer, cross-linking agent (succinic acid) and plasticiser (dibutyl sebacate). The anti-inflammatory activity of ginsenoside-Rd by transdermal delivery was investigated in the inflammatory model of carrageenan-induced paw edema in mice, which was used to evaluate the in vivo transdermal absoption of ginsenoside-Rd administered transdermally.Results:The effect of various penetration enhancers on the in vitro transdermal absorption of ginsenoside-Rd was different. As compared with the control group (without any enhancers), none of them, including 5% turpentine oil,3% flos caryophylli oil,5% N-methyl pyrrolidone,1% urea and 3% borneol, had alone the penetration enhancing effect. However, those including 2% azone,3% menthol and 5% lauryl alcohol alone, had obvious promoting effect with an order of 2% azone> 3% menthol>5% lauryl alcohol. Azone, menthol and lauryl alcohol had synergistic promoting effect when combined with the appropriate concentration (2% azone,5% menthol and 1% lauryl alcohol; 3% azone,1% menthol and 5% lauryl alcohol or 3% azone,3% menthol and 1% lauryl alcohol). The cumulative penetration amount per unit area of the three different combinations, in order, was 3404.18μg/cm2,2832.54μg/cm2 and 2932.53μg/cm2, respectively. In vivo anti-inflammatory experiment, the carrageenan-induced paw edema in mice was inhibited significantly by ginsenoside-Rd 50 mg/kg either administered transdermally or injected intramuscularly as compared to the control group.Conclusions:The best formula of penetration enhancers for the in vitro transdermal absorption of ginsenoside-Rd is the combination of 2% azone,5% menthol and 1% lauryl alcohol. The second is the combination of 3% azone,1% menthol and 5% lauryl alcohol or 3% azone,3% menthol and 1% lauryl alcohol. Ginsenoside-Rd can be absorbed and produce significant anti-inflammatory effect administered transdermally.