4. Summary and conclusions
Both, positively and negatively charged CHON/CHIT NPs have been successfully developed and characterized. The formation and the physicochemical properties of CHON/CHIT NPs were depended on polymer mixing ratio, polymer concentration and molecular weight of CHIT. NPs containing polymers at the ratio far from stoichiometric would make better carriers for ionized drugs as they are less susceptible to charge neutralization and physical destabilization. sCT was successfully loaded into CHON/CHIT NPs with efficiency close to 100% and notably high sCT loading (up to 33%). A new type of NPs composed of CHON and sCT (a binary system) has been successfully developed and characterized. Some of these carriers offer the advantage of a very high drug loading up to 73% and high association efficiency (95%). The particle size of all tested formulations increased in PBS, acetate buffer and in HCl compared to that in water, however most ofthemremainedinthenano-range evenafter 24 h.Both,themedia and the composition of the nanocarriers were found to affect the release of sCT. In all tested formulations the % of sCT released and the quantity of sCT released per mg of NPs at infinity decreased in the following order: PBS > HCl > acetate buffer. CHON/sCT NPs released the largest % of sCT, whereas CHON/CHIT/sCT MMR = 2.5 NPs released the smallest quantity of sCT.
