Preparation and enhanced oral bioavailability of cryptotanshinone-loaded solid lipid nanoparticles.

In this study, solid lipid nanoparticles (SLNs) were successfully prepared by an ultrasonic and high-pressure homogenization method to improve the oral bioavailability of the poorly water-soluble drug cryptotanshinone (CTS). The particle size and distribution, drug loading capacity, drug entrapment efficiency, zeta potential, and long-term physical stability of the SLNs were characterized in detail. A pharmacokinetic study was conducted in rats after oral administration of CTS in different SLNs, and it was found that the relative bioavailability of CTS in the SLNs was significantly increased compared with that of a CTS-suspension. The incorporation of CTS in SLNs also markedly changes the metabolism behavior of CTS to tanshinone IIA. These results indicate that CTS absorption is enhanced significantly by employing SLN formulations, and SLNs represent a powerful approach for improving the oral absorption of poorly soluble drugs.