Characterization and in vitro assessment of paclitaxel loaded lipid nanoparticles formulated using modified solvent injection technique.

This study investigates the design and characterization of solid lipid nanoparticles (SLNs) containing paclitaxel fabricated by a modified solvent injection technique using stearic acid as lipid and stabilized by a mixture of surfactants, for future evaluation of this colloidal carrier system for the oral delivery of paclitaxel, devoid of the side effects of Cremophor EL. SLN formulations of paclitaxel stabilized by mixture of surfactants i.e. lecithin/poloxamer 188 were developed with smaller size and narrow size distribution. The paclitaxel-loaded SLNs exhibited spherical shape with smooth surface as analyzed by transmission electron microscopy (TEM). The average particle size obtained through this method was found to be approximately 113 nm. The zeta potential was between -32 and -39 mV with poloxamer 188. Encapsulation efficiencies of about 72.18 +/- 3.7 and 89.0 +/- 2.4% were achieved using 0.05 and 0.25 mmol of paclitaxel, respectively. Paclitaxel showed a sustained in vitro release profile and was found to follow Higuchi kinetic equations. In vitro cytotoxicity assay confirmed that paclitxel entrapped in SLNs showed higher cytotoxicity against cultured hepatocelluler carcinoma cells than paclitaxel alone. The modified solvent injection technique used in this research proved to be a simple, easily available and effective method to produce SLNs and could be used for controlled delivery of different lipophilic drugs for cancer chemotherapy.