Preparazione e caratterizzazione di due sistemi carrier: beads a base di chitosano e chitosano/alginato; nanoparticelle di N-trimetilchitosano

Chitosan is a very attractive polysaccharide and it is known to be a favorable pharmaceutical material because of its low toxicity, biodegradability, biocompatibility, mucoadhesivity and natural origin. Therefore it forms an ideal hydrophilic carrier system. In this study we described the preparation and characterization of two carrier systems, chitosan and chitosan – alginate beads, and N-Trimethyl Chitosan (TMC) chloride nanoparticles. We realized spherical beads using different polymeric dispersions, chitosan, alginate and chitosan - alginate mixture, to investigate their effect on the phytoterapic anti- inflammatory agent delivery. The main purpose of the present in vitro study is to have some information about their stability in the gastrointestinal tract and to formulate a drug delivery system for the oral administration of this phytoterapic agent. Alginate beads were prepared by ionotropic gelation in presence of CaCl2 and BaCl2 solutions; chitosan beads were prepared by using a TPP (tripolyphosphate) solution as an ionic cross-linking agent and acetone as a coacervating agent; beads of chitosan - alginate mixture were prepared according to the two combined procedures reported above. The swelling degradation behaviour of the bead samples and drug release were investigated using four different medium solutions (PBS pH 7.4, HCl 0.1N pH 1, buffer pH 5). TMC with different degrees of quaternization were synthesized and characterized by 1 H- NMR spectroscopy, XRD and viscosity. Trimethyl Chitosan chloride nanoparticles (TMC-NPs) were prepared according to the ionotropic gelation process of TMC with TPP. The aim of this study is to characterized TMC-NPs (particle size -Z-average mean-, PDI and zeta potential) and evaluate their potential for brain delivery.