Bixin loaded solid lipid nanoparticles for enhanced hepatoprotection--preparation, characterisation and in vivo evaluation.

In the present study, a natural antioxidant drug, bixin was loaded into solid lipid nanoparticles using trimyristin and glycerol monostearate as different lipid matrices and soya and egg lecithin as stabilizers. Developed bixin SLNs were characterized including in vitro drug release and in vivo evaluation of hepatoprotective activity using Wistar rats. Bixin SLNs were prepared by hot homogenisation followed by ultrasonication technique. The particle size ranged from 135.5-352.8 nm with PDI 0.185-0.572. Zeta potential of bixin SLNs was -17.9 to -36.5 mV. Bixin was successfully incorporated into SLNs with entrapment efficiency above 99% and loading efficiency maximum 17.96%. There was no interaction of bixin with selected lipids TM and GMS, confirmed by FTIR studies. DSC studies revealed that preparation method did not change crystallinity of bixin and TM whereas GMS crystallinity was reduced. In vitro drug release studies in Sorensen buffer, pH 7.7 exhibited initial burst effect followed by a sustained release of bixin. Drug release kinetic studies showed that the release was first order diffusion controlled and the n-values obtained from the Korsmeyer-Peppas model indicated the release mechanism was non-Fickian type. In vivo studies revealed better treatment of paracetamol induced hepatotoxicity by bixin SLNs indicating significant localisation of them in liver.