Multilayer structure of lecithin/chitosan nanoparticles (schematic view). The orange arrow indicates a pathway for the diffusion/release of drug molecules
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Nano- and microparticles composed of saccharide and lipid systems are extensively investigated for applications as highly biocompatible drug carriers. A detailed understanding of particle–solvent interactions is of key importance in order to tailor their characteristics for delivering drugs with specific chemical properties.
In this frame lecithin (a commercial mixture of different lipids) and chitosan (a positively charged polysaccharide) can be used to produce nanovectors able to encapsulate lipophilic drugs with low water solubility.
Using the IRIS spectrometer we have investigated the local dynamics of lecithin/chitosan nanoparticles, and the effect of isopropylmiristate (IPM), a lipophilic additive commonly used to improve drug loading efficiency.
The QENS data indicate that IPM, which is fluid at room temperature, increases the mobility of the lipids with respect to pure lipid/saccaharide vectors (about 3 times higher). This microscopic scenario is reflected in the macroscopic kinetics of drug release: the amount of released drug in presence of IPM is about 3 times higher than that of the same nanoparticles without IPM.
Y Gerelli, MT Di Bari, A Deriu, F Cavatorta (Università di Parma, Dipartimento di Fisica, and CNR, Italy), S Barbieri, F Sonvico (Università di Parma, Dipartimento Farmaceutico, Italy), V García Sakai (ISIS)
Research date: November 2008
MT Di Bari et al., Chem. Phys. (2008) 239
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