A Highly Sensitive Hplc Method with Non-extractive Sample Preparation and Uv Detection for Trace Determination of Cinacalcet in Human Plasma

A highly sensitive HPLC method with non-extractive sample preparation and UV detection has been developed and validated for the trace determination of cinacalcet (CIN) in human plasma. Paracetamol (PCM) was used as the internal standard. CIN and PCM were isolated from plasma by protein precipitation with acetonitrile. Chromatographic separation was achieved in isocratic mode on a C18 column (150 mm × 4.6 mm, i.d. 5μm particle size) by a mobile phase consisted of acetonitrile and 50 mM phosphate buffer (50:50 v/v) adjusted to pH of 7.4, at a flow rate of 1.0 mL/min. The eluted compounds were monitored by UV detector at 235 nm. Under the optimum chromatographic conditions, a linear relationship with good correlation coefficient (0.9998) was obtained between the peak area ratio of CIN to that of PCM and the concentration of CIN in a range of 5-5000 ng/mL. The lowest limits of detection and quantitation of the proposed method were 2.5and 7.7 ng/mL, respectively. The intraand inter-day precisions were satisfactory; the relative standard deviations did not exceed 4.12%.The accuracy of the method was proved; the recoveries of CIN from spiked human plasma were in the range of 95.19 99.47 ± 0.11-4.12%.The method has high throughput because of its simple sample preparation procedure and short run time (<6 min). The results demonstrated that the proposed method would have great value when applied for determination of CIN in human plasma for the purposes of pharmacokinetic and bioequivalence studies.