FORMULATION AND EVALUATION OF LINAGLIPTIN MUCOADHESIVE MICROSPHERES

Abstract

Linagliptin an anti-diabetic drug belonging to BCS class-III, inhibits the enzyme, dipeptidyl peptidase-4 (DPP-4). The aim of the present study is to enhance the permeability of linagliptin by increasing its residence time in the stomach. Mucoadhesive microspheres exhibit a prolonged residence time at the site of application and facilitate intimate contact with underlying absorption surface. Mucoadhesive microspheres of linagliptin were prepared by Ionotropic gelation method and single emulsion method. The mucoadhesive microspheres prepared were spherical in shape and were evaluated for various parameters. The microspheres prepared using carbopol by single emulsion method (LMS1) showed swelling index of 1.03, entrapment efficiency of 85±0.57% and the particle size of 135±6mm. The microspheres showed good/excellent flow properties. SEM studies indicate the microspheres were having smooth surface. Mucoadhesion strength was found to be 87% in 7hrs. Drug release was found to be 98.2±0.63% in 8 hrs and release kinetics of the drug was following anomalous transport mechanism. Radiographic studies were performed on rabbit and images indicated that these microspheres were retained successfully in stomach up to 7 hours. FTIR and DSC analysis revealed that there is no interaction between drug and the polymer. The microspheres were stable at accelerated stability conditions as per ICH guidelines. Single emulsion method was showing better results in all the above aspects compared to Ionotropic gelation method. This study concludes that the mucoadhesive microspheres could be one of the most appropriate drug delivery approaches for the successful delivery of linagliptin.