A fast reverse-phase high performance liquid chromatographic tandem mass spectrometry assay for the quantification of clindamycin in plasma and saliva using a rapid resolution package

A new method for the quantitative analysis of clindamycin in human plasma and saliva by liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/ESI-MS/MS) has been developed using a rapid resolution C18 column (2.1 mm × 30 mm × 3.5 μm). A simple deproteinization procedure was applied to the samples before analysis. Multiple reaction monitoring (MRM) mode of precursor–product ion transitions for clindamycin (425.1/126.1) and the internal standard, lincomycin (407.2/126.0) was used. Chromatographic separation was achieved at 0.6 ml/min in less than 1.5 min, with improved peak resolution and sensitivity between drug and internal standard.The assay exhibited a linear dynamic range between 0.05 and 15.0 μg/ml and gave a determination coefficient of 0.991 or better. The limit of quantification of the method was 10 ng/ml in both biological samples. Intra-day and inter-day precision ranged from 7.5% to 11.5%. Good accuracy was observed for both the intra-day and inter-day assays (R.S.D. below ±4%). The suitability of the developed method for the analysis of clindamycin in plasma and saliva samples was demonstrated by the measure of clindamycin in samples taken up to 6 h after oral and intravenous administration of this drug in infectious patients.