Formulation and Evaluation of Extended-Release Tablets of Oxybutynin HCL by Push-Pull Technology

Abstract

The objective of this study was to formulate and evaluate Extended-release oxybutynin chloride tablets using a push-pull osmotic pump system. Oxybutynin HCL is a muscarinic antagonist used for the treatment of overactive bladder with symptoms of urinary incontinence, urgency, and frequency. PPOP are used to deliver drugs that are highly soluble in water. The drug is located in the upper compartment along with osmogent while the lower compartment consists of polymeric osmotic agents. The push pull technique has been formulated in the form of double-layer tablets by wet granulation. The nine formulations were prepared using oxybutynin chloride, HPMC, polyethylene oxide, Nacl, and other excipients, lubricants, and colouring agents. The tablets are coated with a semi-permeable membrane (cellulose acetate), followed by a film coating. The pre-compression parameters (Bulk density, tapped density, Carr’s index, Hausner ratio, and angle of repose) and post-compression parameters of the extended-release tablets (Hardness, friability, weight variation, thickness, and drug content) were all within limits. An FTIR study showed no interaction between API and HPMC and all excipients at the molecular level. In vitro release studies in 0.1 N HCl, and 6.0 phosphate buffer showed that the optimized F5 formulation extended the drug release by 93% after 24 h and the release profile was similar to a product from an innovator.