A method for maintaining and/or enhancing the efficacy of a pharmaceutically active agent in a sustained-release treatment of a bladder disorder is disclosed. In preferred embodiments, the pharmaceutically active agent is botulinum toxin. The method comprises obtaining a biocompatible mucoadhesive thermoreversible hydrogel； and incorporating said pharmaceutically active agent for treatment of a bladder disorder into said biocompatible mucoadhesive thermoreversible hydrogel. The use of a biocompatible mucoadhesive thermoreversible hydrogel comprising a pharmaceutically active agent such as botulinum toxin in the treatment of bladder disorders, and a method for treating bladder disorders by the use of such a composition that does not require injection of the pharmaceutically active agent into the bladder wall, are also disclosed.
