Formulation, Development and Characterization of Transdermal Patches of Glipizide

Abstract

Transdermal patches are innovative drug delivery systems and can be used for achieving efficient systemic effect by passing hepatic first pass metabolism and increasing the fraction absorbed. Like other drugs among the second-generation sulfonylureas, glipizide (GLP) acts by stimulating insulin secretion from pancreatic beta-cells as well as modifying the responsiveness of insulin-sensitive tissues. GLP belongs to biopharmaceutical classification system (BCS) class II and has a low solubility and high permeability. The aim of the current research was to formulate GLP transdermal patches utilizing various polymers combinations. HPMC, ethyl cellulose, eudragit RLPO, eudragit RSPO and permeation enhancer were mixed in different ratios, in presence of polyethylene glycol 400 as plasticizer by the solvent casting evaporation technique. The physicochemical parameters such as flexibility, thickness, smoothness, weight variation, moisture content, hardness, folding endurance and tensile strength were evaluated for the prepared patches. The formulation exhibited flexibility, uniform thickness and weight, smoothness, good drug content (98.65±0.26 to 99.45±0.65%) and little moisture content. The in vitro diffusion studies were carried out using modified Franz diffusion cell using egg membrane as the diffusion membrane and the formulation followed the zero order diffusion mechanism. The formulation containing HPMC: Eudragit as polymers showed faster release rate compared to ethyl cellulose: eudragit. The stability studies indicated that all the patches maintained good physicochemical properties and drug content after storing the patches in different storage conditions. Compatibility studies indicated that there was no interaction between the drug and polymers. The results revealed that, GLP transdermal patch could be considered as promising drug delivery system for diabetic patients. Keywords: Transdermal patches, Glipizide, Sulfonylureas, Physicochemical parameters, In vivo diffusion study