Formulation of Once a Day Controlled Release Tablet of Indomethacin Based on HPMC-Mannitol

p>A hydroxypropyl methylcellulose (HPMC K4M, HPMC K15M, and HPMC K100M) matrix tablet containing Indomethacin along with mannitol was formulated as a function of HPMC viscosity, and was compared with the commercial products. The release characteristics of the matrix tablet were investigated in the intestinal fluid, 6.8 pH phosphate buffer for 12 hours. The formulated products and two marketed products as reference sample were studied for its different physicochemical parameters and in vitro dissolution studies. It was found that the drug release profile decreases with increase in viscosity of polymer and, with increase polymer level in the formulations. Matrix tablets formulated employing Drug:HPMC K15M:mannitol::1:0.25:1 and Drug:HPMC K15M:mannitol::1:0.25:2 gave slow release of indomethacin spread over 12 hours and their dissolution profiles were compared with the Indian marketed product. The dissolution profiles of both the formulations were similar to the dissolution profile of the marketed product, the similarity factor being 74.59 and 68.04 respectively. The dissolution profiles of formulations containing same viscosity grade of HPMC in remarkably different concentrations and different viscosity grade of HPMC in same concentrations were different. Key words: Indomethacin; Controlled release; Hydroxypropyl methyl cellulose; Mannitol; Dissolution. DOI: 10.3126/kuset.v4i1.2884 Kathmandu University Journal of Science, Engineering and Technology Vol.4, No.1, September 2008, pp 55-67

Development of Indomethacin Sustained Release Microcapsules using Ethyl Cellulose and Hydroxy Propyl Methyl Cellulose Phthalate by O/W Emulsification

Indomethacin (IM) sustained release microcapsules were successfully prepared using ethyl cellulose (EC) and hydroxy propyl methyl cellulose phthalate (HPMCP) by o/w emulsification-solvent evaporation technique. The prepared microcapsules were evaluated for size, shape, drug content and in vitro drug release. The microcapsules show sustained release curves at pH 7.2 phosphate buffer for up to 6 h. The data obtained from the dissolution profiles were compared in the light of different kinetics models and the regression coefficients were compared. The in vitro dissolution study confirmed the Higuchi-order release pattern. Particle size and release data analysis from five consecutive batches prepared in the laboratory indicated suitable reproducibility of the solvent evaporation process. The release rate increased exponentially with the addition of HPMCP in EC. IM release rate was observed highest with the highest concentration of HPMCP (3:7 ratio of EC:HPMCP), used in the present studies. On the other hand, IM release rate was lowest when EC and HPMCP combination was used at the ratio of 10:0. When percent of HPMCP was increased, the particle size of microcapsules was decreased. Key words: Indomethacin, sustained release, microcapsule, HPMCP, EC, Higuchi-order  DOI = 10.3329/dujps.v7i1.1223 Dhaka Univ. J. Pharm. Sci. 7(1): 83-88, 2008 (June)