Formulation of Mucoadhesive Microspheres of Irbesartan and Their Evaluation

Abstract

Mucoadhesive microspheres has been accepted as a process to achieve controlled drug delivery by prolonging the residence time of the dosage form at the site of absorption thereby improving and enhancing the bioavailability of drugs. Irbesartan is an Angiotensin receptor blocker (ARB) used mainly for the treatment of hypertension. It competes with Angiotensin II for binding at the AT1 receptor sub type. The mucoadhesive microspheres of Irbesartan were formulated by orifice ionic gelation technique employing polymers like Sodium  Carboxy  methyl  cellulose  and  Carbopol  along  with  Sodium  alginate. The microspheres prepared were discrete, spherical and free flowing. Microspheres were evaluated for particle size, percentage yield, flow properties, drug content, and drug entrapment efficiency, percentage moisture loss, swelling property, in vitro drug release, drug release kinetics, in vitro wash-off test, stability study and drug polymer interaction study by FT-IR. The microencapsulation efficiency was found relatively high with 2% polymer. Average particle size was found in the range of 5.02±0.36 to 9.45±0.43μm. Formulations F6 displayed the best results for. Entrapment efficiency was 85.26±0.43%, swelling-index was 194±3.45% and drug release up to 8h was 94.97%. Drug release was diffusion controlled and followed first order kinetics. The in vitro wash-off test indicated that the microspheres had good mucoadhesive properties. Hence prepared mucoadhesive microspheres may be an effective strategy for the development of easy, reproducible and cost effective method for safe and effective oral drug therapy.