Liquid chromatography-mass spectrometry method for the quantification of corticosteroids, β₂-adrenoreceptor agonists...

Pharmacological treatments of asthma and chronic obstructive pulmonary disease include medications such as inhaled corticosteroids, long- or short-acting β₂-adrenoreceptor agonists and anticholinergics. There is an unmet need for the monitoring of adherence and drug exposure to those therapies since poor adherence and/or inhalation technique may impact the control of the disease and the pharmacological strategy. Since plasma therapeutic drug monitoring only reflects the body exposure in the last few hours, the measurement of hair drug concentrations may be of great interest to assess the chronic exposure. A liquid chromatography - tandem mass spectrometry method was therefore developed for the quantification of corticosteroids, β₂-adrenoreceptor agonists and anticholinergics in human hair. The method was validated according to the European Medicines Agency and Food and Drug Administration guidelines. Sensitivity, accuracy and precision were excellent, allowing the quantification of drugs in the pg/mg range. The method was shown suitable for the analysis of clinical hair samples, demonstrating that it could be used for hair therapeutic drug monitoring in asthma or chronic obstructive pulmonary disease patients.