FDA accepts NDA for topical gel formulation for OAB

June 5, 2008

A new drug application for a topical gel formulation of oxybutynin chloride in the treatment of overactive bladder has been accepted for filing by the FDA, according to Watson Pharmaceuticals, Inc., the manufacturer.

A new drug application for a topical gel formulation of oxybutynin chloride in the treatment of overactive bladder has been accepted for filing by the FDA, according to Watson Pharmaceuticals, Inc., the manufacturer.

The new formulation is a clear, rapid-drying, ethanolic gel designed to deliver consistent oxybutynin concentrations over a 24-hour period in a non-patch transdermal form. By administering oxybutynin through the skin, the treatment avoids first-pass metabolism and the resultant high metabolite levels seen with oral dosing, the company says. A nickel-sized, 1-gram unit dose of oxybutynin gel, applied once daily, delivers about 4 mg of oxybutynin.

The NDA filing is based on data from a phase III, randomized, double-blind, placebo-controlled study involving 789 patients with OAB. In the 12-week study, patients treated with the therapy once daily experienced a highly significant decrease in OAB symptoms versus placebo, including the number of urinary incontinence episodes per day and urinary frequency, and an increase in the average urine volume per void. The gel was well tolerated in the study, and no serious adverse events appeared related to treatment.