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 2000 ng/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 (10.0 ng/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°C, ≤ - 60°C). The validated assay is well suited for the intended clinical study where conventional pharmacokinetic sample collection is not feasible.