Novel and rapid LC–MS/MS method for quantitative analysis of methylphenidate in dried blood spots

Aim: Development and validation of a novel, sensitive, specific and rapid dried blood spots (DBS)-LC–MS/MS method for methylphenidate (MPH), an attention-deficit hyperactivity disorder drug. Methodology & results: Protein precipitation with acetonitrile was used to extract MPH from the DBS cards. Chromatographic separation was achieved on a Zorbax C18 column using an isocratic mobile phase composed of acetonitrile and 5 mM ammonium formate buffer (20:80, v/v) at a flow rate of 0.5 ml/min. MPH was quantified over a linear range of 200–25,000 pg/ml. Conclusion: The clinical DBS-LC–MS/MS method was successfully validated as per the US FDA's Bioanalytical Method Validation Guidance to support an ongoing pediatric pharmacokinetic study.