SPL Set ID: 7bd31561-4c76-4c6b-819b-492549886673

Oxybutynin chloride is an antispasmodic, muscarinic antagonist. Each oxybutynin chloride extended-release tablets, USP contains 5 mg, 10 mg or 15 mg of oxybutynin chloride USP, formulated as a once-a-day controlled-release tablet for oral administration. Oxybutynin chloride is administered as a racemate of R- and S-enantiomers. Chemically, oxybutynin chloride is d,l (racemic) 4-diethylamino-2-butynyl phenylcyclohexylglycolate hydrochloride. The empirical formula of oxybutynin chloride is C 22 H 31 NO 3 •HCl. Its structural formula is: Oxybutynin chloride is a white crystalline solid with a molecular weight of 393.9. It is readily soluble in water and acids, but relatively insoluble in alkalis. Oxybutynin chloride extended-release tablets, USP also contains the following inert ingredients: hypromellose, hydrogenated vegetable oil, microcrystalline cellulose, lactose monohydrate, povidone, colloidal silicon dioxide, magnesium stearate, methacrylic acid and ethyl acrylate co-polymer dispersion, triethyl citrate, talc, titanium dioxide, polyethylene glycol/macrogol, iron oxide yellow non-irradiated, isopropyl alcohol and iron oxide red non-irradiated. The ink contains shellac glaze (modified), black iron oxide non-irradiated, N-butyl alcohol, propylene glycol and ammonium hydroxide. Chemical Structure System Components and Performance Oxybutynin chloride extended-release tablets, USP uses an enteric coated hydrophilic hydrogel matrix to deliver oxybutynin chloride at controlled rate over approximately 24 hours by diffusion mechanism. The system comprises of a core, which contains the drug, rate controlling hydrogel and other excipients. The core is surrounded by a partially or complete pH dependent membrane. Hence, when the drug reaches the acidic medium, in stomach minimal drug release will occur and when it reaches an environment of pH 5.5 and above, the outer membrane will be dissolved exposing the inner core. This inner core will partially hydrate to form a gel layer and the drug release will occur via diffusion mechanism from a gel layer and subsequently through gel erosion. Meets USP Dissolution Method 4. FDA approved acceptance criteria differs from the USP acceptance criteria.