Title
Carboxymethyl tamarind gum-mediated enhancements in citric acid-crosslinked carboxymethylcellulose hydrogel films: optimizing mechanical properties, swellability, drug loading capacity and sustained drug release
Authors
VISHWAJEET SAMPATRAO GHORPADE, KAILAS KRISHNAT MALI, NITIN HINDURAO SALUNKHE, ROHIT DILIP GAIKWAD and REMETH JACKY DIAS

Received August 15, 2025
Published Volume 60 Issue 1-2 January-February
Keywords carboxymethyl cellulose, carboxymethyl tamarind gum, hydrogel, citric acid, drug delivery

Abstract
Carboxymethyl tamarind gum (CMTG) and carboxymethyl cellulose (CMC) have emerged as promising biopolymers for hydrogel formation due to their excellent swelling properties and biocompatibility. Citric acid crosslinked CMC CMTG hydrogel films have been developed for controlled delivery of moxifloxacin, a model drug, thereby addressing the limitations inherent in hydrogel films composed of individual polymers. The hydrogel films were synthesized through an esterification-crosslinking mechanism utilizing the solvent-casting technique. Characterization of the films was performed using ATR-FTIR, TGA, and solid-state 13C NMR spectroscopy. Additionally, the films were evaluated for total carboxyl content, contact angle, tensile strength, swellability, drug loading, drug release, and hemocompatibility. The ATR-FTIR, TGA, and solid-state 13C NMR analyses confirmed the formation of ester crosslinks between CMC and CMTG. The incorporation of CMTG enhanced the total carboxyl content, mechanical strength, and contact angle of the hydrogel films. However, the swellability and drug loading in the hydrogel films decreased with increasing concentrations of CMTG. All films demonstrated the capability to control the release of moxifloxacin for up to 24 h. The optimized batch (HFC) exhibited a tensile strength of 79.46 MPa, equilibrium swelling of 44.81±2.4 g/g in phosphate buffer (pH 7.4), drug loading of 464.70 mg/g, and released 87.46% of the drug at the end of 24 h. All hydrogel batches demonstrated controlled drug release characterized by non-Fickian (anomalous) diffusion kinetics. In conclusion, the results suggest that the citric acid-crosslinked CMC-CMTG hydrogel films exhibit superior mechanical strength, reduced matrix erosion, enhanced drug loading, and controlled drug release compared to hydrogels prepared using CMC and CMTG individually.