Abstract
A high pressure liquid chromatography-diode array detector (HPLC-DAD) method using amylose tris(3,5-dimethylphenyl carbamate) chiral stationary phase (Chiralpak AD-H) is described for the determination of doxylamine enantiomers in human plasma. Doxylamine enantiomers were separated on a Chiralpak AD-H column using a mobile phase composed of n-hexane-2-propanol-diethylamine (98:2:0.025, v/v/v). Diphenhydramine was used as an internal Standard (IS). Doxylamine was extracted from plasma samples using dichloromethane:hexane (1:2 v/v), which yielded high extraction yields (87%), satisfactory precision (RSD < 1.05%), and good selectivity. Linearity was found in the 8–40 µg · mL−1 range with the limits of detection 0.13 µg · mL−1. Doxylamine enantiomers were well separated with no interference from endogenous plasma constituents. The method developed, showed a good linearity, sensitivity, and repeatability.
ACKNOWLEDGMENTS
This work was supported by The Research Fund of Istanbul University Project Number: UDP-1644.
Notes
a Flow rate: 1.0 mL · min−1.
b k' 1, k' 2: Capacity factors of the first eluted enantiomer and second eluted enantiomer, respectively.
c α: Selectivity factor.
a The results are the mean of 4 determination.