Preparation, characterization and in vivo distribution of solid lipid nanoparticles loaded with cisplatin

An emulsification dispersion-ultrasonication method was employed to prepare solid lipid nanoparticles (SLN) loaded with cisplatin. The conventional antitumor drug cisplatin (CDDP) was incorporated into SLN to obtain a targeted and less toxic drug delivery system. The CDDP-SLNs were spherical and uniform in transmission electron microscopy (TEM) photography. The mean particle size and zeta potential were 121 ± 15 nm, and –46.4 ± 10.3 mV, respectively. Also, a novel cation exchange resin method was adopted to investigate the encapsulation efficiency (EE%) of the SLN. This method is based on the principle of cation exchange between drugs and resins, and the EE% of the optimal formulation was 82.3%. The in vitro release profile revealed that CDDP was released from SLN efficiently and completely in normal saline (NS) compared with other release media. A pre-column derivatization HPLC method was established for in vivo assay of cisplatin. A tissue distribution study was conducted in male rats after iv administration of 8 mg · mL^–1 CDDP-SLN and cisplatin NS, and it was found that CDDP-SLN has a targeted effect to the liver as well as a low concentration in the kidney in rats. These results indicated that emulsification dispersion-ultrasonication is a simple, easy, available and effective method for preparing CDDP-SLN, and the cation exchange resin method is a feasible and suitable method to evaluate the EE% of CDDP-SLN. CDDP-SLN prepared by this method was proved to be a targeted and less toxic drug delivery system.