Polysaccharide-based chiral phase under polar organic mode of elution in the determination of the enantiomeric purity of emtricitabine an anti-HIV analogue nucleoside.

This work reports the separation of FTC enantiomers using an amylose tris[(S)-1-phenylethylcarbamate] coated onto APS-Nucleosil (7 microm particle size, 500 A pore size, 20% w/w, 15 x 0.46 cm ID) chiral column under polar organic elution mode. Good enantioselectivity (alpha=1.9) with excellent enantioresolution (R(S)=3.3) was achieved by the use of methanol with 0.02% of triethylamine acetate as mobile phase. The method allows the accurate determination of as low as 0.2% of each enantiomer as an impurity. The validated method proved to be reliable and sensitive for the quantification of both enantiomers as impurity in different batches of emtricitabine and beta-D-(+)-FTC.