ANALYSIS OF TRAZODONE AND m-CPP IN HUMAN SERUM BY RPLC AND UV-PHOTODIODE ARRAY DETECTION

A simple, rapid, valuable and cost-effective RP-LC method was developed to measure the antidepressant trazodone (TRZ) and its metabolite 1-(m-chlorophenyl)piperazine (m-CPP) in human serum using an UV-photodiode array (PDA) detector and a conventional C18 analytical column. Extraction was performed in n-hexane using buspirone as the internal standard (IS) while chromatographic separation being attained within 7 min at the constant flow-rate of 1 ml min-1, using a mobile phase composed of 0.1M NaH2PO4, pH5:methanol (40:60, v/v). The UV-PDA detector was set either at the two λmax, 213 (analytes) and 240 nm (IS), or at variable wavelengths. The method was validated by a serum-spiking procedure employing known amounts of TRZ, m-CPP and a fixed IS concentration. Linearity was satisfactory in wide concentration ranges: 24-4,100 ng ml-1 for TRZ and 20-2000 ng ml-1 for m-CPP, showing r2 values between 0.9977 and 0.9999. Extraction yields were constant and accounted for by, on average, 68%, 82% and 79% for TRZ, m-CPP and IS respectively, while no significant interference being reported with drugs among those usually administered with TRZ. The method’s sensitivity resulted adequate and suitable for analyzing also serum samples at very low-levels of TRZ.