Repositioning Oxybutynin Hydrochloride: State of the Art in Synthesis, Mode of Action, Metabolism, and Formulations

Abstract

For decades, oxybutynin hydrochloride has been prescribed to improve bladder control in cases of incontinence and excessive urination frequency. This review summarizes synthetic methods enabling the preparation of the racemic drug and, in a detailed manner, preparation of (S)-2-cyclohexyl-2-hydroxy-2-phenylacetic acid, a key intermediate in the synthesis of (S)-oxybutynin. The mode of action and metabolism are briefly addressed in order to explain the main adverse effects associated with its use and to justify the evolution observed in the diverse commercial formulations. Repositioning opportunities are discussed in terms of clinical trials for the management of hyperhidrosis, hot flashes, and obstructive sleep apnea.