Aim: To study the morphology, particle size distribution and biological reliability of the norcantharindin (NCTD)-loaded microemulsion and pharmacokinetics of the W/O norcantharidin-loaded microemulsion in mice.
Methods: The concentration of NCTD in plasma and tissues were determined by GC method. The data obtained were processed using 3P87 program.
Results: The mean particle diameter of microemulsion was (44 +/- 9) nm. The concentration-time curve of NCTD-loaded microemulsion and NCTD injection was fitted to a two-compartment model. At the same dosage, the pharmacokinetic study for NCTD-loaded microemulsion showed the NCTD microemulsion had relatively longer circulating time in mice. Area under the curve of concentration versus time (AUC), mean residence time (MRT) and half life (T1/2) for microemulsion and injection were (29.7 +/- 0.9) mg x h x L(-1), (9.25 +/- 0.09) mg x h x L(-1), (110 +/- 11) h, (86.7 +/- 0.8) h, (103 +/- 12) h, (42 +/- 4) h, respectively. Targeting index of NCTD microemulsion in liver and kidney in mice were 0.43 and 0.12 after iv NCTD-loaded microemulsion. The effects of biological reliability was not significantly different between NCTD microemulsion and NCTD injection in vivo and in vitro.
Conclusion: The liver targeting absorptive capability of NCTD-loaded microemulsion was enhanced and the release time was extended compared with NCTD injection. While the microemulsion vehicles could decrease the kidney distribution of NCTD.