RT Journal Article T1 Reversible pH-sensitive chitosan-based hydrogels. Influence of dispersion composition on rheological properties and sustained drug delivery A1 Iglesias González, María Nieves A1 Galbis Fuster, Elsa A1 Valencia Barragán, Concepción A1 Paz Báñez, María Violante de A1 Galbis Pérez, Juan Antonio AB The present work deals with the synthesis of micro-structured biomaterials based on chitosan (CTS) for their applications as biocompatible carriers of drugs and bioactive compounds. Twelve dispersions were prepared by means of functional cross-linking with tricarballylic acid (TCA); they were characterized by Fourier transform infrared spectroscopy (FT-IR), modulated temperature differential scanning calorimetry (MTDSC) and scanning electron microscopy (SEM), and their rheological properties were studied. To the best of the authors’ knowledge, no study has been carried out on the influence of CTS concentration, degree of cross-linking and drug loading on chitosan hydrogels for drug delivery systems (DDS) and is investigated herein for the first time. The influence of dispersion composition (polymer concentration and degree of cross-linking) revealed to exert a marked impact on its rheological properties, going from liquid-like to viscoelastic gels. The release profiles of a model drug, diclofenac sodium (DCNa), as well as their relationships with polymer concentration, drug loading and degree of cross-linking were evaluated. Similar to the findings on rheological properties, a wide range of release profiles was encountered. These formulations were found to display a well-controlled drug release strongly dependent on the formulation composition. Cumulative drug release under physiological conditions for 96 h ranged from 8% to 67%. For comparative purpose, Voltaren emulgel® from Novartis Pharmaceuticals was also investigated and the latter was the formulation with the highest cumulative drug release (85%). Some formulations showed similar spreadability values to the commercial hydrogel. The comparative study of three batches confirmed the reproducibility of the method, leading to systems particularly suitable for their use as drug carriers. PB MDPI SN 2073-4360 YR 2018 FD 2018 LK http://hdl.handle.net/10272/14849 UL http://hdl.handle.net/10272/14849 LA eng NO Iglesias González, M.N., Galbis Fuster, E., Valencia Barragán, C., Paz Bañez, M.V., Galbis Pérez, J.A.: "Reversible pH-sensitive chitosan-based hydrogels. Influence of dispersion composition on rheological properties and sustained drug delivery". Polymers. Vol. 10, n. 4, 392 (2018). https://doi.org/10.3390/polym10040392 NO The authors would like to thank the Ministerio de Economía y Competitividad, Spain (GrantMAT2016-77345-C3-2-P) and the Junta de Andalucía, Spain (Grant P12-FQM-1553) of Spain for financial support.The authors also thank Francisco Miguel Morales and Bertrand Lacroix for their contribution in the study ofCTS-crosslinked hydrogels micro-morphologies by means of scanning electron microscope. DS Repositorio Institucional de la Universidad de Huelva RD 14 jul 2026