HPLC method for simultaneous determination of cefprozil diastereomers in human plasma.

A high-performance liquid chromatography method was developed for the determination of cefprozil diastereomers in human plasma. Cefprozil exists as cis and trans isomer at the ratio of 90:10. Plasma samples were prepared by protein precipitation using acetonitrile, trichloroacetic acid and methylene chloride. After the mixtures were vortexed and centrifuged, the aqueous supernatant was injected into a reversed-phase C8 column. The mobile phase consisted of acetonitrile, glacial acetic acid and distilled water at the volume ratio of 5.5:1.75:92.75 (pH 2.7). The signals were monitored with UV detection at 280 nm. The calibration curves of cis and trans isomer were linear in concentration ranges of 0.1-25 and 0.02-2.5 microg/mL with the correlation coefficient of 0.9999 and 0.9989, respectively. After oral administration of cefprozil in humans, Cmax and Tmax of total cefprozil were 18.80 +/- 2.14 microg/mL and 2.06 +/- 0.62 h. This method was sensitive with excellent selectivity and reproducibility, and successfully applied to a bioavailability study of cefprozil in healthy subjects.