Development and application of a high-performance liquid chromatographic method for the determination of in vitro drug release of levodopa, carbidopa, and entacapone from a tablet formulation.

A simple, precise, and accurate high-performance liquid chromatographic method was developed and validated to determine percent drug release of levodopa (LEV), carbidopa (CAR), and entacapone (ENT) from its combination dosage form. A mixture of acetonitrile and buffer was used as the mobile phase for reversed-phase liquid chromatographic separation for determination of the in vitro drug release of LEV, CAR, and ENT. A dissolution test was conducted at 75 rpm with United States Pharmacopeia (USP) apparatus-II (paddle) by using pH 5.