Drug-in-cyclodextrin-in-polymeric nanoparticles: A promising strategy for rifampicin administration.

The aim of this work was to develop novel chitosan (CH) based nanoparticles (NPs) for rifampicin (RIF) delivery. RIF, a lipophilic molecule, was incorporated inside NPs as a complex with an anionic cyclodextrin, sulphobutyl-ether-β-cyclodextrin (SBE-β-CD). NPs were then prepared through the ionic gelation method by exploiting the interaction between CH and SBE-β-CD-RIF complex (CH/SBE-β-CD-RIF NPs), possibly in the presence of other crosslinkers, like carboxymethylcellulose (CH/SBE-β-CD-RIF/CMC NPs) and pentasodium tripolyphosphate (CH/SBE-β-CD-RIF/TPP NPs). NPs were then characterized for their size, ζ-potential, morphology, yield, drug loading, stability, mucoadhesion, in vitro drug release and antimicrobial activity. Results demonstrated that the functional properties of loaded NPs, like their size, ζ-potential, and stability, varied on the basis of the CH/crosslinker weight ratio. Interestingly, all the developed NPs had a round shape and were characterized by high yield values and mucoadhesive properties. Among them, NPs based on CH/SBE-β-CD-RIF and CH/SBE-β-CD-RIF/CMC have gained high drug loading, provided a sustained release of RIF and showed the best antimicrobial activity. Thus, both types of NPs may be considered as promising nanocarriers for the release of RIF.