5‐Fluorouracil Encapsulated Chitosan Nanoparticles for pH‐Stimulated Drug Delivery: Evaluation of Controlled Release Kinetics

Nanoparticles consisting of human therapeutic drugs are suggested as a promising strategy for targeted and localized drug delivery to tumor cells. In this study, 5‐fluorouracil (5‐FU) encapsulated chitosan nanoparticles were prepared in order to investigate potentials of localized drug delivery for tumor environment due to pH sensitivity of chitosan nanoparticles. Optimization of chitosan and 5‐FU encapsulated nanoparticles production revealed 148.8 ± 1.1 nm and 243.1 ± 17.9 nm particle size diameters with narrow size distributions, which are confirmed by scanning electron microscope (SEM) images. The challenge was to investigate drug delivery of 5‐FU encapsulated chitosan nanoparticles due to varied pH changes. To achieve this objective, pH sensitivity of prepared chitosan nanoparticle was evaluated and results showed a significant swelling response for pH 5 with particle diameter of ~ 450 nm. In vitro release studies indicated a controlled and sustained release of 5‐FU from chitosan nanoparticles with the release amounts of 29.1–60.8% due to varied pH environments after 408 h of the incubation period. pH sensitivity is confirmed by mathematical modeling of release kinetics since chitosan nanoparticles showed stimuli‐induced release. Results suggested that 5‐FU encapsulated chitosan nanoparticles can be launched as pH‐responsive smart drug delivery agents for possible applications of cancer treatments.