Abstract The aim of the current study is to design a sustained release matrix tablet of metformin HCl to maintain plasma level of drug for prolong period of time. Metformin HCl is antihyperglycemic agent used in the treatment of type II Non insulin dependent diabetes mellitus. Sustained release formulation of metformin HCl prolong drug absorption in the upper GI tract and permits once daily dosing in patient with type II diabetes mellitus. This newer formulation may enhance patient compliance compared to conventional immediate release metformin HCl. Metformin HCl present significant challenges due to its poor inherent compressibility, high dose and high water solubility. So matrix tablet of metformin HCl is formulated by different combination of matrix forming polymers such as hydroxypropyl methylcellulose and hydroxylpropyl cellulose by direct compression method. PVPK30 is used as a binder. Magnesium stearate and micro crystalline cellulose are used as a lubricant and filler respectively. Drug and polymer compatibility study is done by IR spectroscopy. The formulated powder mixture is evaluated for precompression parameters such as bulk density, tapped density, angle of repose, compressibility index and Hausner’s ratio for determining flow properties of mixture. Prepared tablets are subjected to post compression parameter such as hardness, thickness, weight variation, friability and drug content. All formulations showed compliance with pharmacopoeial standards. No physicochemical interaction is found between drug and polymers in IR spectrums. It would be desirable in dissolution study that formulation containing lower concentration of polymer will earlier drug release.
Keywords Metformin hydrochloride, sustained release matrix tablets, HPMC