Preparation and Physicochemical Characterization of Ofloxacin-Loaded Alginate-Chitosan Nanogel: Comparison to Ofloxacin-Loaded Alginate Nanogel

Abstract

Background: Alginate is a versatile polymer that has been used in various industries, including food and pharmaceuticals. We showed that chitosan, a positively charged polymer, enhances the physicochemical properties of drug carriers in drug delivery. Objectives: The aim of this study is to investigate the potential of an alginate-chitosan nanogel (Alg-Chi NG) drug delivery system in comparison to an alginate nanogel. Our specific goal is to compare the properties of an alginate nanogel (Alg-NG) containing ofloxacin with an Alg-Chi NG loaded with ofloxacin, to determine the potential benefits of incorporating chitosan in the nanogel formulation. Methods: The Alg-NG containing ofloxacin was prepared using the emulsification/internal gelation method. The Alg-NG was formed through a chelation reaction between alginate and calcium to make a nanogel. Additionally, ionic interactions between the amine group of chitosan and the carboxylic group of alginate led to the formation of a polyelectrolyte complex known as Alg-Chi NG. Results: The size of Alg-NG and Alg-Chi NG was around 70 ± 4.7 nm and around 150 ± 6.2 nm, respectively. We showed that the Fourier transform infrared spectroscopy of Alg-Chi NG had a new peak at 1736 cm⁻¹ that confirmed a polyelectrolyte complex between alginate and chitosan. The release of ofloxacin from Alg-NG and Alg-Chi NG after 6 hours was 54.5 ± 2.56% and 34.8 ± 2.51%, respectively. These results suggest that using chitosan could reduce the drug release rate. The kinetic model for both formulations was more closely fitted with the Higuchi model, in which Alg-Chi NG was closer to 1. Conclusions: According to the results, alginate-chitosan nanogel could be a practical approach for the drug delivery of hydrophilic drugs.