Abstract
A selective high performance liquid chromatographic (HPLC) method was developed for the separation and quantification of bisoprolol enantiomers in pharmaceutical products. The method is highly specific where another co-formulated drug, hydrochlorothiazide, did not interfere. Baseline resolution was achieved by using teicoplanin macrocyclic antibiotic chiral stationary phase (CSP), known as Chirobiotic T, with fluorescence detection at excitation/emission wavelengths 275/305 nm. The polar ionic mobile phase (PIM) consisting of methanol-glacial acetic acid-triethylamine, (100:0.020:0.025), (v/v/v) has been used at a flow rate of 1.5 mL/min. All analytes with S-(−)-atenolol as the internal standard were conducted at room temperature. The stability of bisoprolol enantiomers under different degrees of temperature was also studied. The results showed that the drug is stable for at least 7 days at 70°C. The method was validated for its linearity, accuracy, precision, and robustness. An experimental design was used during validation to evaluate method robustness. The calibration curves were linear over the range of 5-250 ng/mL for each enantiomer, with a correlation coefficient of 0.999 for both enantiomers. The overall recoveries of S-(−)- and R-(+)-bisoprolol from pharmaceutical products ranged from 97.6 to 100.5% with %RSD ranging from 0.7 to 2.6%. The limit of quantification (LOQ) and limit of detection (LOD) for each enantiomer were 5 and 2 ng/mL, respectively. The method proved to be of chiral quality control for bisoprolol formulations by HPLC.