Mucoadhesive films of Losartan Potassium for Buccal delivery: Design and Characterization

Abstract:

Buccal delivery is considered to be an important alternative to the peroral route for the systemic administration of drugs. Losartan potassium is an angiotensin II receptor antagonist with an oral bioavailability of only 33% due to extensive first pass metabolism. Mucoadhesive buccal films of losartan potassium were prepared using hydroxypropyl methyl cellulose (HPMC) and retardant polymers ethyl cellulose (EC) or eudragit RS 100. Thermal analysis by DSC of formulations show no interaction between drug and polymers. Ex vivo permeation studies of losartan potassium solution through porcine buccal mucosa showed 90.2 % absorption at the end of 2 hours. The films were subjected to physical investigations such as uniformity of thickness, weight, drug content, folding endurance, tensile strength, elongation at break, surface pH and mucoadhesive strength. Films were flexible and those formulated from EC were smooth whereas those prepared from Eudragit were slightly rough in texture. The mucoadhesive force, swelling index, tensile strength and percentage elongation at break was higher for those formulations containing higher percentage of HPMC. In vitro drug release studies reveal that all films exhibited sustained release in the range of 90.10 to 97.40 % for a period of 6 hours. The data was subjected to kinetic analysis which indicated non fickian diffusion for all formulations except E2. Ex vivo permeation studies through porcine buccal mucosa indicate that films containing higher percentage of the mucoadhesive polymer HPMC showed slower permeation of the drug for 6-7 hours.

Key words: Losartan, eudragit, ethyl cellulose, buccal mucosa