Preparation and Optimization of Labeled Chitosan Nanoparticles and Evaluation of their Release from Transdermal Drug Delivery System

Biocompatible nanoparticles are widely used in biomedical engineering. In this study، chitosan nanoparticles were prepared using ionic gelation method in view of two determining factors namely method of adding chitosan into the tripolyphosphate (TPP) solution and thermal shock application. With regard to the concentration of chitosan and TPP solutions as two variables، the mean particle size of chitosan nanoparticles and their preparation yield were optimized using response surface method. According to previous studies and some preliminary experiments، the chitosan and TPP solution concentration ranges were determined to be 0. 5-2. 5 mg/mL and 0. 25-1. 25 mg/mL، respectively. The optimum values of 1. 25 mg/mL and 0. 6 mg/mL were obtained for chitosan and TPP solution concentrations in the order given. The optimized response value for the chitosan nanoparticles size was found to be 54 nm and preparation yield was 62%. The Zeta potential of resulting spherical nanoparticles was around 31 mV. Chitosan-fluorescein isothiocyanate (FITC) polymer was prepared based on the reaction between isothiocyanate functional group of FITC and primary amine functional group of chitosan. FTIR analysis was performed to demonstrate the presence of new bond formation. Labeled chitosan nanoparticles were prepared in the optimized condition using chitosan-FITC polymer. The release behavior of the labeled chitosan nanoparticles from transdermal patches was evaluated. The mean size of chitosan-FITC nanoparticles was determined to be 70 nm. Finally، it was shown that the chitosan nanoparticles were not able to release from acrylic adhesive film without using a method to speed up their diffusion.