Abstract: Provided is a crystalline IPA solvate of 2(R)-(3-Chloro-4-methanesulfonyl-phenyl)-3-((R)-3-oxo-cyclopentyl)-N-pyrazin-2-yl-propionamide as a glucokinase activator which increases insulin secretion in the treatment of, for example, type II diabetes.

Abstract: An erodible pharmaceutical composition providing a unique zero order controlled release profile is herein described. The erodible composition contains a therapeutically active substance having a solubility not greater than 80 mg/mL, a hydroxypropyl methylcellulose derivative and erosion modifiers depending on drug solubility and drug loading, such as lactose and polyoxyalkylene derivatives of propylene glycol, as well as other inert materials such as binders and lubricants. The hydroxypropyl methylcellulose derivative is most preferably a hydroxy-propylmethyl having a methoxy content of about 19-30% and hydroxypropyl content of 7-12%, a methoxy degree of substitution from 1.1 to 2.0, a molecular weight of approximately 20,000 to 26,000 daltons and a viscosity of a 2% w/w polymer solution at 25.degree. C. ranging from 50 to 100 cps. The composition erodes with a constant erosion volume for a desired time period.