An investigation on liver-targeting microemulsions of norcantharidin.

Based on the clinical fact that norcantharidin (NCTD) injection frequently causes urinary organ damnification, we prepared a NCTD w/o microemulsion as an alternative to improve the solubility and enhance the live uptake of NCTD. The optimal microemulsion formulation consisted of 7% water, 45% soybean lecithin/ethanol (2:1), and ethyl oleate, with the droplet size of 44.5 +/- 8.6 nm. Pharmacokinetics study showed that NCTD microemulsion had relatively longer circulating time in mice than NCTD injection after a single intravenous injection at a dose of 5 mg/kg. Moreover, the overall drug targeting efficiency of liver was enhanced from 3.66% to 6.10%. These results suggest that a NCTD microemulsion system is a promising candidate for the treatment of hepatogenic diseases.