Dynamics of nanoparticles for drug delivery
11 Nov 2009



Nano- and micro-particles that are composed of saccharide (sugar-like) and lipid (molecules such as fats and oils) components can be produced for potential applications as highly-biocompatible drug carriers.

Multilayer structure of lecithin / chitosan nanoparticles (schematic view). The orange arrow indicates a pathway for the diffusion/release of drug molecules.

A detailed understanding of particle–solvent interactions is of key importance in order to tailor their characteristics for delivering drugs with specific chemical properties. For example, lecithin (a commercial mixture of different lipids) and chitosan (a positively charged polysaccharide) can be used to produce nanoparticles able to encapsulate lipophilic (fat-soluble) drugs which would otherwise have 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 data indicate that IPM, which is fluid at room temperature, increases the mobility of the lipids with respect to pure lipid / saccharide nanoparticles by about three times. This microscopic scenario is reflected in the macroscopic kinetics of drug release: the amount of released drug in the 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)

Contact: Prof A Deriu, Antonio.Deriu@fis.unipr.it

Further reading: MT Di Bari et al., Chem Phys (2008) 239