Method development and validation for simultaneous determination of lumefantrine and its major metabolite, desbutyl lumefantrine in human plasma using RP-HPLC/UV detection

A simple, specific, precise and rapid RP-HPLC–UV method was developed for simultaneous determination of lumefantrine and its metabolite desbutyl lumefantrine in human plasma. Experimental parameters were optimized and the method was validated according to standard guidelines. The method showed adequate separation for lumefantrine and desbutyl lumefantrine and best resolution was achieved with Supelco Discovery HS C18 RP (150 mm × 4.6 mm, 5 μm) column using acetonitrile and 0.05% trifluroacetic acid (70:30, v/v) as a mobile phase pumped at a flow rate of 1.0 ml/min and wavelength of 335 nm. The method was linear over the concentration range of 10–12,000 ng/ml. The lower limit of detection (LLOD) and lower limit of quantification (LLOQ) for lumefantrine were 10.0 and 18.0 ng/ml, while for desbutyl lumefantrine were 7.5 and 15.0 ng/ml, respectively. The proposed method was efficiently applied for determination of lumefantrine and desbutyl lumefantrine concentrations in plasma samples for pharmacokinetic studies.