Abstract
An accurate, precise and sensitive reverse-phase high-performance liquid chromatography (RP-HPLC) bioanalytical approach was developed for the simultaneous estimation of cinnarizine (CIN) and domperidone (DOM) in rat plasma using irbesartan (IRB) as an internal standard (IS). The proposed RP-HPLC approach was validated as per the latest ICH M10 guidelines. The analytes (CIN and DOM) and IS were extracted from plasma samples using the protein precipitation strategy. Chromatographic separation is accomplished by a C-18 Sunfire(TM) (5 mu m, 250 mm x 4.6 mm) analytical column, using an isocratic mobile phase consisting of acetonitrile-methanol in 30:70 proportions at a flow rate of 1 mL/min. The detection of all three constituents was recorded at a wavelength of 270 nm with a UV detector. DOM, CIN and IS were eluted at 3.2, 4.5 and 6.1 min, respectively, utilizing a total run time of 10 min. The lower limit of quantification (LLOQ) was 5 ng/mL for CIN and DOM in rat plasma. The proposed RP-HPLC approach was linear in the 5-200 ng/mL range for CIN and DOM. The recovery of the method was greater than 95%, and the relative uncertainty was less than 2%, indicating that the proposed bioanalytical approach was accurate and precise. The limit of detection was established as 1.1 ng/mL for CIN and 1.7 ng/mL for DOM. The created approach was found to be robust and passed all validation criteria; thus, the proposed RP-HPLC approach can be employed successfully for the simultaneous assessment of CIN and DOM in rat plasma.