IN-VITRO, EX-VIVO SKIN PERMEATION AND BIOLOGICAL EVALUATION OF 18-β-GLYCYRRHITIC ACID TRANSDERMAL PATCHESAbstract
Objective: a Transdermal patch is a promising approach that allows continuous input of drugs with short biological half-lives. 18 β-Glycyrrhizic acid (GA) is chemically pentacyclic triterpenoid which possesses powerful anti-inflammatory action. The present study was designed to formulate GA reservoir-type transdermal patches using piperine as bioenhancer. Method: Transdermal Patch of GA was prepared using heat seal technique using 23 factorial design allowing for independent variables like penetration enhancers, formulation matrix and rate controlling membranes. The GA patches were evaluated for in-vitro and ex-vivo drug permeation through cellophane membrane and rat skin respectively. The biological evaluation regarding skin irritation study and the anti-inflammatory effect of GA patches on rat paw edema were tested and compared with standard Aceclofenac patch. Result: The reservoir-type patch of F4 formulation, containing 5% menthol as a permeation enhancer, 42% ethanol, 2% carpool 934 gel bases (50 g) with 0.5% piperine provided an improved sustained release of phytopharmaceuticals through transdermal administration. The anti-inflammatory action F4 formulation showed no skin irritation with significant inhibition of rat paw edema compared with standard patch. Conclusion: The GA patch was demonstrated the feasibility for future biopharmaceutical study in clinical trials.