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 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″ 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 due to spot size and storage temperature (e.g., at 60°C, ≤-60°C). The validated assay is well suited for the intended clinical studies where conventional PK sample collection is not feasible.