Preparation And Drugs Release Property Of Cataplasma Matrix For Transdermal Drug Delivery System

Transdermal drug delivery system (TDDS) attracts much attention for its advantages. However, the skin barrier limits the development of TDDS. Chemical enhancers and physical methods have been used for enhancing transdermal drug transportation. In order to develop novel dosage forms for TDDS, this thesis focused on the preparation and drugs release property of cataplasma matrix, using baicalin as drug model. Then the effect of physical penetration enhancer using low-frequency pulse was studied in vitro transdermal delivery experiment.First of all, the prescription matrix and preparation process were optimized through orthogonal design according to evaluation of adhensive and mechanical performance. Two prescriptions were performed. One was chitosan:0.2g, PVA:0.3g, gelatin:0.8g, adhesive GAT:1.5g, adhesive GAE:2.0g and glycerol:0.3g. The other was sodium alginate:0.3g,carbopol:0.2g, triethamolamine:0.4g, PVA:0.2g, weight rate of GAT and GAE: 0.25:0.25, glycerin:1.8g, citric acid: 0.03, sodium benzoate:0.01.Secondly, the release experiment and in vitro transdermal delivery experiment were conducted with Franz diffusion cells. Baicalin cataplasma showed good in vitro release and percutaneous permeation property. Results indicated that baicalin cataplasma prepared from sodium alginate had the better drugs release and percutaneous permeation property. The release rates were 239.70μg·cm^-2·h^-1 and 98.20μg·cm^-2·h^-1. The permeation rates were 0.34μg·cm^-2·h^-1 and 0.23μg·cm^-2·h^-1.Thirdly, the physical penetration enhancer was also studied to enhance the permeation effect. Results showed that the enhancement effect of physical method was better than the chemical way, when the frequency of pulse was 10Hz and the current density was set at 0.5 mA/cm2. The 2h penetration amount of baicalin was obtained as 24.00μg/cm2. The permeation rate was 12.87μg·cm^-2·h^-1. The combined use of chemical and physical penetration enhancers had the best effect in three methods. The 2h penetration amount of baicalin was obtained as 34.42μg/cm2. The permeation rate was 19.45μg·cm^-2·h^-1. Further investigation of the combination enhancers will overcome the skin barrier of TDDS.