External Cross-linked Mucoadhesive Microbeads for Prolonged Drug Release: Development and In vitro Characterization

Mucoadhesive microbeads of low methoxyl pectin were prepared, either alone or in combinations with hydroxypropyl methyl cellulose, sodium carboxymethyl cellulose, methyl cellulose and carbopol 934P, by ionotropic gelation. The influence of copolymers on mucoadhesivity, microbeads characteristics and in vitro drug release was investigated. Spherical microbeads with 78.69±0.59 to 85.84±0.78% drug entrapment and of a size of 791.90±4.58 to 960.88±4.61 μm were prepared. The concentration of cross linking agent affects the encapsulation efficiency of microbeads. Mucoadhesiveness of microbeads was dependent on the concentration of copolymers. The formulations exhibiteda pH-dependent release and followed diffusion-controlled first-order kinetics.