RP-LC Determination of the cis-Isomer of Glimepiride in a Bulk Drug Substance

A rapid reversed-phase high-performance liquid chromatographic procedure is developed and validated for the resolution of the cis-isomer of 1-p-2-(3-ethyl-4-methyl-2-oxo-3-pyrroline-1-carboxamido) ethyl] phenyl] sulfonyl]-3-(trans-4-methylcyclohexyl) urea, a dopamine agonist in bulk drugs. The cis-isomer and glimepiride were baseline resolved on a Waters Symmetry column (50 × 4.6 mm, 3.5 μm) using a mobile phase system containing water: tetrahydrofuran (75:25; v/v. The chromatographic resolutions between cis-isomer and glimepiride were found to be greater than two. The developed method was extensively validated and proved to be robust. The limit of detection and the limit of quantification of cis-isomer were 500 and 1,500 ng mL⁻¹, respectively, for 10 μL injection volume. The percentage recovery of the cis-isomer ranged from 97.3 to 102.0 in bulk drug samples of glimepiride. Glimepiride sample solution and mobile phase were found to be stable for at least 48 h. The proposed method was found to be suitable and accurate for the quantitative determination of the cis-isomer in bulk drugs.