Darifenacin.

Darifenacin is a muscarinic M3 selective receptor antagonist, which is intended for symptomatic treatment of urge incontinence and/or increased urinary frequency and urgency as may occur in patients with overactive bladder syndrome. Darifenacin extended release tablets were developed to overcome the inconvenience of multiple dosing per day that is necessary with the immediate release formulation. There is therefore a need of administrating darifenacin in an oral dosage form once or twice daily in the form of extended release tablets  provide therapeutically effective plasma concentrations of darifenacin for the treatment of overactive bladder in humans. Therefore the present investigation concerned with the development of once-a-day darifenacin hydrobromide extended release tablets to extend the duration of action up to 24 hrs by controlling the dissolution rate using different viscosity grades of HPMC.