Functionalized Lipid Nanoparticles-Cellophane Hybrid Films for Molecular Delivery: Preparation, Physicochemical Characterization, and Stability

Lipid nanoparticles functionalized with the sunscreen 2,4‐dihydroxybenzophenone (FLNPs) have been prepared by the ultrasound method and embedded in highly hydrophilic cellophane supports (regenerated cellulose, RC), creating biocompatible hybrid films (RC‐FLNPs samples). The morphology of the FLNPs was studied with transmission microscopy, whereas the surface and interior chemical composition was analyzed by micro‐Raman spectroscopy. RC‐FLNPs hybrid films were prepared from the immersion of two cellophane supports with different thicknesses and water uptake properties (RC‐3 and RC‐6) in an aqueous dispersion of FLNPs. The structure of this hybrid material was visualized with bright‐field microscopy, which clearly showed the inclusion of the FLNPs in the cellophane matrix. The stability of the RC‐FLNPs films with respect to both aqueous environments and time was demonstrated by NaCl diffusion measurements. The reduction in the diffusion coefficient through the nanoparticle‐modified films compared with the original supports confirms the presence of nanoparticles for concentration gradients of up to 0.4 M (osmotic pressure around 10 bar), indicating the stability of the hybrid hydrophilic material, even in aqueous environments and under matter flow conditions for a period of 21 days. © 2011 Wiley‐Liss, Inc. and the American Pharmacists Association J Pharm Sci 100:4815-4822, 2011