Enantiomeric analysis of citalopram in human plasma by SPE and chiral HPLC method

Citalopram is a serotonin transporter (SERT) inhibitor and is used as a potent anti-depressant drug. S-(+)-Citalopram is twice therapeutically active than its racemic mixture. The present article describes effective, selective and reproducible methods of chiral analysis of citalopram in human plasma. The sample preparation of human plasma was carried out by Solid Phase Extraction (SPE) C ₁₈ cartridges with elution via methanol having 0.1% acetic acid. The chiral analysis was achieved on AmyCoat column (150 × 46 mm) of the amylase type CSP, by using n-hexane-2-propanol-DEA (95:05:0.2, v/v/v) as mobile phase. Flow rate of mobile phase was 0.5 mL/min with detection at 240 nm. The values of k [R-(-)-], k [S-(+)-], α and Rs were 3.56, 4.00, 1.12 and 1.22, respectively. Linearity was in the concentration range of 100-500 μg/L with 10.0 ng as the detection limit. The percentage recovery by SPE was 98.00 and the validation parameters proved the precision of the method and its applicability for the determination of chiral citalopram in human plasma. S-(+)-Citalopram reacted more in human plasma than R-enantiomers.