A chitosan-based magnetic system for response surface methodology (RSM) optimization of the influencing variables in ciprofloxacin loading/releasing.

Abstract

We optimized the loading and release processes of Ciprofloxacin (CIP) on Fe₃O₄/Chitosan (FCS) magnetic nanoparticles (MNPs) for drug delivery applications. The Fe₃O₄ MNPs were synthesized via the coprecipitation method and subsequently coated with Chitosan to enhance their properties. Ciprofloxacin was used as a model drug. We characterized the structure, morphology, physicochemical, and magnetic properties of both the Fe₃O₄/CS MNPs and the CIP-loaded Fe₃O₄/CS MNPs using various techniques, including SEM, EDX, FTIR, XRD, VSM, TGA, and elemental mapping. In the spectrum of Fe₃O₄/CS/CIP, the appearance of absorption bands at 3437 cm^-1 and 2908 cm^-1 for -OH, and -NH₂ functional groups of chitosan, the bands at 1378 cm^-1 and 1066 cm^-1 belong to its CH-OH and -C-O-C groups, and the bands at 1945 cm^-1 and 1606 cm^-1 of CIP carbonyl groups confirm modification of magnetite NPs by CS and loading CIP by the modified adsorbent. The average crystallite size was obtained about 20 nm based on the diffraction data. The modified adsorbent has a pHpzc of 6.1. The effects of different factors such as pH, time, temperature, and initial concentration on CIP's loading and release processes were studied using response surface methodology (RSM). Our findings indicated that the concentration of CIP was the most significant factor influencing the loading process, while time was the most crucial factor for the release process. The optimal conditions for loading were determined to be at pH 9 with a stirring time of 13 h, whereas the optimal conditions for release were at pH 2.7 with a stirring time of 9 h within a range of 1 to 9 h. One-factor-at-a-time studies indicated that a concentration of 20 ppm and an exposure time of 8 h had the most significant effects on loading and release, respectively.