Separation and determination of clenbuterol by HPLC using a vancomycin chiral stationary phase

Enantiomers of clenbuterol were separated by a new HPLC method on a chiral column. Enantiomeric resolution was achieved on a vancomycyin macrocyclic antibiotic chiral stationary phase known as chirobiotic V with UV detection at 247 nm. The polar ionic mobile phase consisting of methanol-triethylamine-glacial acetic acid (100 + 0.05 + 0.025, v/v/v), was used at a flow rate of 1.0 mL/min. The method was validated for linearity, accuracy, precision, and robustness. Standard linear calibration curves were established for the R-(-) and S-(+) enantiomers over the range of 0.2-20 microg/mL, and an average recovery of 98.0% and a mean relative standard deviation of 1.5% were obtained at 5.0 microg/mL. The lower limit of detection was 0.05 microg/mL for each enantiomer. The mean recovery for R-(-) and S-(+)-clenbuterol enantiomers from plasma was 91.0-97.0% at 0.20-20 microg/mL. The method was successfully used to identify and quantify the clenbuterol enantiomers in human plasma.