Quantitative analysis of clofazimine (Lamprene®), an antileprosy agent, in human dried blood spots using liquid chromatography-tandem mass spectrometry

An LC-MS/MS method was developed and validated for bioanalysis of clofazimine in human dried blood spot (DBS) samples in support of a clinical study on multidrug-resistant tuberculosis in developing countries. The validated assay dynamic range was from 10.0 to 2000ng/mL using a 1/8 inch DBS punch. The accuracy and precision of the assay were +/- 11.0% (bias) and 13.5% (CV) for the LLOQs (10.0ng/mL) and +/- 15% (bias) and 15% (CV) for all other QC levels. The assay was proved to be free from the possible impact owing to spot size and storage temperature (e.g. at 60 degrees C, -60 degrees C). The validated assay is well suited for the intended clinical study where conventional pharmacokinetic sample collection is not feasible.