Insulin-Loaded SLN Prepared with the Emulsion Dilution Technique: In Vivo Tracking of Nanoparticles after Oral Administration to Rats

Abstract

Insulin-loaded solid lipid nanoparticles (SLN) were prepared according to a solvent dilution method from O/W emulsions using isovaleric acid as organic phase. Insulin was derivatized with fluorescein isothyocianate (FITC) obtaining a fluorescent marker to be used in in vivo experiments. FITC-insulin and native insulin–loaded SLN were quite similar with regard to their mean sizes and encapsulation efficiency. SLN intestinal uptake was then investigated administering FITC-insulin loaded SLN on healthy male Wistar rats. Significant drug accumulation within intestinal lymphatic system was recovered, but the immune system seems to play an important role in SLN degradation: further studies are necessary to improve the results on blood glucose level.

Keywords:

• FITC-insulin
• intestinal uptake
• SLN

Acknowledgements

This work was supported by a grant from the Italian Government (MIUR, Cofin 2004).