Novel drug nanocarriers combining hydrophilic cyclodextrins and chitosan

Abstract

The aim of this study was to explore the possibility of obtaining nanoparticles(NPs) containing high amounts of cyclodextrin (CD) derivatives such ascarboxymethyl-β-CDand sulphobutyl ether-β-CD. The rationale used was to combine the drug solubilizing and stabilizingproperties of cyclodextrins (CDs) with the mucoadhesive properties of chitosan(CS) in a unique nanoparticulate drug delivery system. The size of the resultingNPs was affected by the nature of the CDs, ranging between 275 and 550 nm,whereas the zeta potential of the NPs was always positive and close to+35 mV. The positive zeta values, together with the results from NMR studies, suggest that CSis the major compound on the surface of the NPs, while CD molecules are stronglyassociated with the NP matrix. The empirical composition of the NPs was quantified byelemental analysis and the results indicated that the amount of CD associated with theNPs was strictly dependent on its electrostatic charge. Finally, in vitro stability studiesindicated that the presence of CDs in the NP structure can prevent the aggregation of thisnanometric carrier system in simulated intestinal fluid. Overall, this new type of NPrepresents an attractive drug delivery platform of particular interest for the oraladministration of drugs with low bioavailability.