A VALIDATED LC METHOD FOR THE DETERMINATION OF CHIRAL PURITY OF (R)-3-((1-METHYLPYRROLIDIN-2-YL) METHYL)-5-(METHYLSULFONYLMETHYL)-1H-INDOLE: A KEY RAW MATERIAL OF ELITRIPTAN HYDROBROMIDE

A simple and accurate normal phase liquid chromatographic method was developed for the determination of chiral purity of (R)-3-((1-methylpyrrolidin-2-yl) methyl)-5-(methylsulfonylmethyl)-1H-indole, R-isomer used as key starting raw material in the manufacturing of Elitriptan hydrobromide bulk drug. Chromatographic separation between (R)-3-((1-methylpyrrolidin-2-yl) methyl)-5-(methylsulfonylmethyl)-1H-indole and its opposite isomer (S)-3-((1-methylpyrrolidin-2-yl) methyl)-5-(methylsulfonylmethyl)-1H-indole, S -isomer was achieved using a Chiralpak IA column using a mobile phase containing n-hexane, ethanol, isopropyl alcohol and trifluoro acetic acid (98:1.5:0.5:0.1 v/v/v/v). The resolution between the two isomers was found to be more than 2.0. The limit of detection (LOD) and limit of quantification (LOQ) of the S – isomer was 0.15 and 0.5 μg mL-1, respectively, for 10 μL injection volume. The percentage recoveries of the S-isomer ranged from 96.5 to 105.3 in the samples of (R)-3-((1-methylpyrrolidin-2-yl) methyl)-5-(methylsulfonylmethyl)-1H-indole. The test solution and mobile phase was observed to be stable up to 24 h after the preparation. The developed method was validated as per International Conference on Harmonization guidelines in terms of LOD, LOQ, precision, linearity, accuracy, robustness and ruggedness.