A pH-Sensitive Chitosan/Oxidized-Kappa-Carrageenan based Nano-Antibiotic for Sustained and Controlled Release of Amoxicillin

Nowadays antibiotic resistance is one of the most serious problems. Therefore, there is a need for sustained and controlled drug release systems for antibiotics. The aim of this study was to develop a nano-antibiotic system using biocompatible and antimicrobial polymers that are abundant in nature. Frequently used amoxicillin was chosen as the antibiotic. Before nanoparticle synthesis kappa-carrageenan was oxidized and 1.2% carboxyl, and 23.08% aldehyde groups were obtained, as confirmed by Fourier-transform infrared spectroscopy. A combination of polyelectrolyte complexation and ionic gelation was occurred in the nanoparticle synthesis. For the optimal temperature, CaCl2 concentration and polymer ratio of 37 °C, 1.5% and 6:1, respectively, the results of hydrodynamic size measurements indicated the size was 414.4 nm. Drug loading encapsulation was successful with an efficiency of 73.28%. Drug release was monitored for 95 h, and drug release was 93% and 85%, respectively, at pH 6.0 and pH 7.4. It is shown by the mathematical models that the drug release profile can be explained by the Higuchi and first-order models since R2 values were higher than for the other models. As a result, it was observed that the obtained nano-antibiotic delivery system performed a long-term drug release of approximately 4 days in a pH-sensitive manner and would be a promising drug delivery system.