Quantitative determination of MCC-555, a novel insulin sensitizer in beagle dog plasma by high-performance liquid chromatography with fluorescence detection

A sensitive high-performance liquid chromatographic method with fluorescence detection has been developed for determination of MCC-555 (5-[[6-(2-fluorbenzyl)-oxy-2-naphy] methyl]-2,4-thiazolidinedione) in beagle dog plasma. Sample preparation was done by protein precipitation with acetonitrile and a synthetic intermediate of MCC-555 (5-[[6-(2-fluorbenzyl)-oxy-2-naphy] methylene]-2,4-thiazolidinedione) was used as the internal standard (IS). The isocratic mobile phase consisted of acetonitrile–10 mmol/l sodium phosphate buffer (pH 4.5) (65:35, v/v) was delivered at a flow rate of 1 ml/min to a Kromasil C18 reversed-phase column (250 mm × 4.6 mm, 5 μm). The compounds were detected by fluorescence detection, using an excitation wavelength of 232 nm, and emission wavelength of 352 nm. Calibration curves of MCC-555 were linear in the concentration range of 0.005–2.0 μg/ml. Intra- and inter-day precision ranged from 3.4 to 5.4% and 3.0 to 8.8%, respectively. No endogenous interferences were observed with either MCC-555 or IS. The assay is simple, economical, precise, and is directly applicable to pharmacokinetic studies in beagle dogs involving three dose administrations.