Patent ID: 7959946

Claim:
A pharmaceutical dosage form having a first and second active drug, said dosage form comprising: (a) a controlled release core comprising: i) a core comprising at least one pharmaceutically acceptable excipient and only one active drug that consists of metformin hydrochloride; and ii) a sustained release coating surrounding the core; (b) optionally a first seal coating surrounding the sustained release coating that does not contain an active pharmaceutical ingredient and that rapidly disperses or dissolves in water and (c) an immediate release pioglitazone layer surrounding the sustained release coating of the controlled release core or the first seal coating if present comprising pioglitazone hydrochloride and a binder wherein the immediate release pioglitazone layer is free of a surfactant and not less than 90%, of the pioglitazone hydrochloride is released from the dosage form within 30 minutes when tested according to the United States Pharmacopeia (USP) 26, with Apparatus 1 at 100 rpm, 37° C. and 900 ml of 0.3 M KCl—HCl Buffer, pH 2.0, and after storage at 40° C. and 75% relative humidity for three months, the total pioglitazone related compounds or impurities in the dosage form is not more than 0.6% as determined by high performance liquid chromatography and each individual pioglitazone related compound or impurity in the final dosage form is not more than 0.25% wherein the pioglitazone related compounds and impurities are: (i) (+/−)-5-[p-[2-(5-ethyl-2-pyridyl)ethoxy]benzyl]-5-hydroxy-2,4-thiazolidinedione; (ii) (z)-5-[p-[2-(5-ethyl-2-pyridyl)ethoxy]benzylidene]-2,4-thiazolidinedione; (iii) (+/−)-5-[p-[2-(5-ethyl-2-pyridyl)ethoxy]benzyl]-3-[2-(5-ethyl-2-pyridyl)ethyl]-2,4-thiazolidinedione; (iv) (+/−)-ethyl-2-carbamoyltio-3-[4-[2-(5-ethyl-2-pyridyl)ethoxy]phenyl-]propionate; and (v) ethyl-3-p-[2-(5-ethyl-2-pyridyl)ethoxy]phenyl-propionate.