High performance liquid chromatography method for the determination of doxycycline in human plasma

A simple, low-cost, sensitive and selective HPLC method was developed for the determination of doxycycline in human plasma. The method has a detection limit of 0.008 mu g mL(-1) and a limit of quantification of 0.02 mu g mL(-1). Calibration curves were linear over a large dynamic range, namely within 0.02-5.0 mu g mL(-1), which allowed accurate determination of doxycycline peak levels in human plasma after administration of 50-200 mg tablets and also the low plasma levels obtained 72 hours after drug administration.