Development and validation of a liquid chromatographic enantiomer separation method for the estimation of (S)​-​enantiomer in sitagliptin

A direct chiral separation method development was carried out for sitagliptin and its (S)-enantiomer on ten diverse chiral stationary phases. Chiral stationary phases, which were tested include, R, R Whelk-O1 column, macrocyclic glycopeptides namely, Chirobiotic R (Ristocetin A), Chirobiotic V (Vancomycin), Chirobiotic T (Teicoplanin), Chirobiotic TAG (Teicoplanin aglycone), OJ-H, OJ-RH belonging to tris (4-methylbenzoate) of cellulose. Chiral selectivity was observed on polysaccharide based CSP columns namely Chiralpak IA-3, Chiralpak IC-3 belonging to tris-(3,5-dimethylphenyl carbamate) of amylose, tris-(3,5-dichlorophenyl carbamate) of cellulose respectively and OD-H (tris-3,5-dimethylphenylcarbamate) of cellulose. Better enantioselective separation has been achieved on cellulose tris-(3,5-dichlorophenyl carbamate) column (Chiralpak IC-3), using IPA and n-hexane as mobile phase, both containing 0.05% ethylene diamine and at 0.5 mL/min flow rate. Detection was carried out at 266nm using PDA detector and column maintained at 35ºC. The method was validated for precision, accuracy, linearity and robustness. The advantages of the method are rapid equilibration and less solvent consumption due to short column length. Efficient enantio separation (Resolution 3.38) is due to small particle size of 3 μm. Therefore this method is suitable for chiral purity determination of sitagliptin and its (S)-enantiomer.