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.

Determination of nebivolol and valsartan in a fixed-dose combination by liquid chromatography.

An accurate and reproducible liquid chromatographic assay method was developed and validated for the determination of nebivolol and valsartan in a capsule formulation. Buffer-acetonitrile (55 + 45, v/v) was used for reversed-phase liquid chromatography to determine the contents of nebivolol and valsartan in the combination-capsule dosage form. The method was validated by determining parameters such as specificity, linearity, limits of detection and quantitation, precision, accuracy, and robustness.

Determination of Cefdinir by a stability-indicating liquid chromatographic method.

A simple, fast, specific, stability-indicating, and precise reversed-phase liquid chromatographic method was developed for the determination of Cefdinir in its different dosage forms, i.e., capsules and suspensions.

Determination of inorganic nitrate impurity from nicorandil and its tablet dosage form by simple reversed phase liquid chromatographic method.

A simple, fast, precise, specific and economical reverse phase liquid chromatographic method was developed for determination of nitrate (NIT) impurity from nicorandil (NIC) and its tablet dosage form. NIT is process impurity as well as a degradation product of NIC. This article is based on application of amino propyl silane (APS) column for determination of NIT in presence of NIC and various excipients using potassium nitrate as a standard.

Determination of rosuvastatin in the presence of its degradation products by a stability-indicating LC method.

A forced degradation study was successfully applied for the development of a stability-indicating assay method for determination of rosuvastatin Ca in the presence of its degradation products. The method was developed and optimized by analyzing the forcefully degraded samples. Degradation of the drug was done at various pH values.