PREPARATION AND EVALUATION OF MUCOADHESIVE MICROSPHERES OF DILTIAZEM HYDROCHLORIDE

The objective of this study was to formulate and evaluate diltiazem hydrochloride (DH) mucoadhesive microspheres (MS) using sodium alginate with pectin, carbopol and HPMC. DH has a half-life of about 6 hrs and is taken twice daily in large number of patients which leads to patient compliance. DH-MS were prepared by orifice ionic gelation method using sodium alginate as coating polymer and pectin, carbopol and HPMC as mucoadhesive polymers. The prepared MS were evaluated for particle size, FTIR study, swelling ratio, in vitro wash off test and in vitro drug release. DH-MS were found to be spherical, discrete, free flowing, % mucoadhesive property and swelling index was good in all the formulations. The drug release was better at 1:3 core: coat ratio than the 1:1 and 1:2 ratios irrespective of mucoadhesive polymers. In vitro drug release suggests the best fit model was found to be Korsemeyer peppas and with ‘n’ value was less than 0.5 indicating drug release mechanism is Fickian diffusion and diffusion controlled. All the formulations showed optimum drug release at the end of desired period. F-3, F-6, F-9 was found to be optimum which showed maximum drug release over an extended period of 24 h with maximum microencapsulation efficiency and good mucoadhesive property.