A new drug nanocarrier consisting of chitosan and hydoxypropyleyclodextrin

The objective of the present work was to develop a new drug nanocarrier consisting of nanoparticles made of chitosan and cyclodextrins. The rationale behind the design of this new nanosystem, was to simultaneously implement the cyclodextrin drug complexation power and the inherent properties of chitosan nanoparticles, in a unique delivery system. The complexation with the cyclodextrin permits the solubilization as well as the protection for sensitive drugs, whereas the entrapment in the chitosan network is expected to facilitate their absorption. Chitosan nanoparticles including hydroxypropylcyclodextrins could be prepared by the ionic crosslinking of chitosan with sodium tripolyphosphate in the presence of cyclodextrins. Two hydrophobic drugs, triclosan and furosemide, were selected as models for complexation with the cyclodextrin and further entrapment in the chitosan nanocarrier. The resulting nanosystems were thoroughly characterized for their size and zeta potential and also for their ability to associate and deliver the complexed drugs. The results showed that the size of the nanoparticles was slightly affected by the incorporation of cyclodextrins, whereas the xi potential did not suffer a significant modification. Moreover, the complexation of the drugs with the cyclodextrin facilitated their entrapment into the nanoparticles, increasing up to 4 and 10 times (for triclosan and furosemide, respectively) the final drug loading of the nanoparticles. These results led to the conclusion that the drug -cyclodextrin complex was efficiently retained in the nanoparticulate structure. Finally, the in vitro release profile observed for these nanoparticles was characterized by an initial fast release followed by a delayed release phase. In conclusion, this new nanosystem offers an interesting potential for the transmucosal delivery of hydrophobic compounds. (c) 2006 Elsevier B.V. All rights reserved.