PREPARATION OF TMC NANOPARTICLES FOR OCULAR DELIVERY

MACCIONI, ANNA MARIA;CARDIA, MARIA CRISTINA;MARCI, LUISA;M. C. Meloni

2013-01-01

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Abstract

Purpose:. The use of povidone iodine to treat conjunctivitis is well known, but it requires the administration of povidone iodine solution several times daily, generally associated to other antibacterial agents. The aim of this work was to prepare povidone iodine loaded N-trimethyl chitosan nanoparticles (PI-TMC NP) for ocular delivery, in order both to obtain a formulation at controlled and prolonged release and a transcorneal drug transport. Methods: TMC has been synthesized through methylation reaction with methyl iodide in basic medium to obtain a polymer with a DQ around 27 %. PI-TMC NP have been prepared through ionotropic gelation method using tripolyphoshate (TPP). We prepared two different formulations of PI- TMC NP (5% w/w and 5% w/v) and we characterize them in the aim to choose the best one for therapeutic use. The obtained polymer has been characterized by means of spectroscopic methods (FTIR, 1H-NMR and XRD). The freeze dried polymer and the PI- TMC NP have been analysed by CP-MAS 13C. Water dispersions of TMC have been submitted to physical- chemical analyses, such as determination of pH, rheological, evaporation-freezing assays and stability studies. Results: The particle-size and zeta potential of the PI- TMC NP were measured with a Malvern Zetasizer Nano. The particle-size distribution of the nanoparticles is reported as polydispersity index (PDI). Loading capacity and efficacy assays have been performed together with preliminary release studies. In vitro preliminary release tests showed that povidone iodine has been released from the polymer matrix in a prolonged and controlled manner.Conclusions: On the bases of above TMC nanoparticles could be considered a promising carrier for prolonged and controlled ophthalmic drug delivery system.