Development of a validated LC-MS/MS method for determination of doxofylline on rat dried blood spots and urine: Application to pharmacokinetics

► Development and validation of a LC-MS/MS method for determination of doxofylline on dried blood spots and urine. ► The method was successfully applied to study pharmacokinetics of doxofylline in rats. ► Good recoveries were obtained for doxofylline and caffeine (IS) by using simple methanol from dried blood spots and ODS-SPE cartridges for urine extraction.