The purpose of present research work was to design and optimize compression coated tablet to provide an
immediate release of hydrochlorothiazide in stomach and extended release of metoprolol succinate in intestine.
Compression coated tablet was prepared by direct compression method which consisted of metoprolol succinate extended
release core tablet and hydrochlorothiazide immediate release coat layer. Barrier coating of Hydroxy Propyl Methyl
Cellulose (HPMC) E15LV was applied onto the core tablets to prevent burst release of metoprolol succinate in acidic
medium. A 32 full factorial design was employed for optimization of the amount of polymers required to achieve extended
release of drug. The percentage drug release at given time Q3, Q6, Q10, Q22; were selected as dependent variables. Core and
compression coated tablets were evaluated for pharmaco-technical parameters. In vitro drug release of optimized batch
was found to comply with Pharmacopoeial specifications. Desired release of metoprolol succinate was obtained by
suitable combination of HPMC having high gelling capacity and polyethylene oxide having quick gelling capacity. The
mechanism of release of metoprolol succinate from all batches was anomalous diffusion. Optimised batch was stable at
accelerated conditions up to 3 months. Thus, compression coated tablet of metoprolol succinate and hydrochlorothiazide
was successfully formulated.
Keywords: Compression coated tablet, hydroxy propyl methyl cellulose, immediate release, in vitro release, polyethylene oxide,
Rights & PermissionsPrintExport