MUCOADHESIVE MICROPARTICLES OF CARBOXYMETHYL CHITOSAN FOR SITE SPECIFIC DELIVERY OF PANTOPRAZOLE: FORMULATION AND IN VITRO CHARACTERIZATION

Carboxymethyl chitosan, a water soluble modified carboxymethyl substituted chitosan derivative have distinct and unique properties, rendering them effective to form selective permeable mucoadhesive film or membranes. In the formulation of chitosan microsphere an acidic environment is essentially required that may degrade acid sensitive moiety, peptide or protein drugs. Mucoadhesive microparticle of carboxymethyl chitosan was designed and developed for site specific sustained release of Pantoprazole sodium. Thus prolong the residence time at the absorption site by intimate contact with the mucus layer thereby increase bioavailability, reduce the frequency of dose administration and also prolong the drug release. The mucoadhesive microparticles were prepared by Orifice ionic gelation method using carboxymethyl chitosan in combination with Carbopol 934 and HPMC K15. Entrapment efficiency was in the range of 42.4 to 84.6 %. SEM studies revealed that microparticles were discrete, spherical and free flowing. Microparticle exhibited good mucoadhesive property in the in vitro wash off test and found that Carbopol 934 had greater mucoadhesive strength than that of HPMC K15. A sustained release of Pantoprazole sodium was obtained from mucoadhesive microparticle. Stability study of optimized batch was carried out and drug content found was retained with permissible limits and there was no significant difference in the drug content.