Patent ID: 7976871

Claim:
A process for the preparation of a modified release dosage form comprising metformin hydrochloride prepared by using dual retard technique to control the release of metformin, wherein the said dual retard technique is a combination of a matrix formulation and a reservoir formulation, said process comprising: a) preparing micro matrix particles consisting of metformin hydrochloride and one or more hydrophobic release controlling agents consisting of poly(ethyl acrylate, methyl methacrylate, trimethylammonioethyl methacrylate chloride) 1:2:O.1; poly(ethyl acrylate, methyl methacrylate, trimethylamonioethyl methacrylate chloride) 1:2:0.2; and poly(ethyl acrylate, methyl methacrylate) 2:1; and b) coating said micro matrix articles with one or more hydrophobic release controlling agents selected from the group consisting of waxes selected from the group consisting of beeswax, carnauba wax, microcrystalline wax, and ozokerite; fatty alcohols selected from the group consisting of cetostearyl alcohol, stearyl alcohol; cetyl alcohol and myristyl alcohol; and fatty acid esters selected from the group consisting of glyceryl monostearate; glycerol monooleate, acetylated monoglycerides, tristearin, tripalmitin, cetyl esters wax, glyceryl palmitostearate, glyceryl behenate and hydrogenated castor oil.