| abstract |
The present disclosure provides extended release trihexyphenidyl compositions suitable for once- or twice-daily administration. The compositions comprise a core comprising organic acid that is coated with a t least one drug layer comprising trihexyphenidyl hydrochloride, and a functional coat over the drug-layered core. The extended release compositions of the disclosure provide extended release of trihexyphenidyl hydrochloride, with reduced Cmax, and a Cmin : Cmax ratio of ≥ 0.4, while maintaining a therapeutically effective concentration for a period of at least about 16 hours. The compositions of the disclosure improve solubility of trihexyphenidyl hydrochloride, at a pH of greater than or equal to 5, to maintain its minimum effective concentration at such pH. In certain embodiments, the compositions of the disclosure comprise an IR drug layer to provide extended release with a minimal lag time, while maintaining a therapeutically effective concentration of trihexyphenidyl hydrochloride for a period of at least about 16 hours. |