Design and Characterization of Transdermal Delivery of Repaglinide

In the present work an attempt has been made to formulate and evaluate the transdermal patches of repaglinide using various blends of polymer. The polymeric combinations EC/PVP and EC/HPMC used for the formulation of transdermal patches showed good film forming property. The patches formed were thin, flexible, smooth and transparent. The weight variation tests showed less variation in weight and suggesting uniform distribution of drug and polymer over the mercury surface. The thicknesses of the transdermal patches were found to increase on increasing concentration of hydrophilic polymers like PVP and HPMC. All the patches showed good flexibility and folding endurance properties. The result suggests that the formulations with increased hydrophilic polymer concentration showed long folding endurance. The moisture content in the patches were found to be low and formulations with more hydrophilic polymer concentrations showed more percentage moisture content. The drug content analysis showed minimum variations suggesting uniform distribution of drug. The in-vitro drug release studies showed that formulations EPA3, EPB3, EPC3, EHA3, EHB3 and EHC3 with increased concentration of hydrophilic polymer showed rapid release. Formulations EPC1 and EHC1 showed sustained release. The in-vitro permeation studies showed that the required target flux is achieved with formulations EPC1 and EHC1 which also produces a sustained release of the drug. Surface morphological studies by SEM showed the patch showed uniform smooth surface and did not loose integrity after release. The results of compatibility studies by FTIR showed no interaction between the drug and polymers. The result of stability studies no change in the physical appearance and drug content suggesting that the formulations remained stable during storage. It is concluded that solvent casting method using mercury substrate is useful for successful development of matrix type transdermal patches. The sustained release of drug from the transdermal patches suggests that the frequency of administration may be reduced. Further, the transdermal patches may improve the bioavailability of the drug by avoiding hepatic first pass metabolism. Hence we can conclude that the polymer matrix provide sustained delivery of drug and these systems can be used to deliver drugs with short half life and low therapeutic index through transdermal drug delivery systems