Formulation development and evaluation of gastroretentive mucoadhesive tablets of glimepiride using natural polymers

Abstract

Glimepiride, a third-generation sulfonylurea is poorly soluble anti-diabetic drug. Currently, the use of natural gums and mucilage is of increasing importance in pharmaceutical formulations as valuable drug excipients. Natural plant-based materials are economic, free of side effects, biocompatible and biodegradable. The development of mucoadhesive sustained release drug delivery system is recommended in order to enhance the bioavailability. A mucoadhesive tablets were developed using the natural polymer sodium alginate and gum tragacanth. Mucoadhesion is a complex phenomenon which involves wetting, adsorption and interpenetration of polymer chains. The tablets of glimepiride were prepared by direct compression method. Pre-compression parameters were evaluated. The tablets were evaluated for post-compression parameters such as thickness, hardness, average weight, friability and In vitro release studies. All the compositions were resulted in adequate pharmacopoeial limits. The varying concentration of polymers was found to affect on in-vitro drug release and mucoadhesive strength. In vitro drug release of gastro retentive tablet of glimepiride shown that the formulation F5 was found to be the best formulation as it releases 98.78%.  Glimepiride in a sustain release manner for an extended period of time (up to 12 hrs). The release data was fitted to various mathematical models such as higuchi, korsmeyer-peppas, first order and zero order to evaluate the kinetics and mechanism of the drug release. Prepared tablets of glimepiride may prove to be a potential candidate for safe and effective controlled drug delivery over an extended period of time for gastro retentive drug delivery system. Keywords: Glimepiride, Gastro retentive, Anti-diabetic drug, Direct compression method