Ellagic Acid-Loaded Microsponges Impregnated Chitosan-Guar Gum Hydrogel for Wound Therapy: Investigation on Rheology, Antioxidant, and Antimicrobial Activities

The therapeutic efficacy of ellagic acid could be improved by developing suitable carrier system. The present research was to develop ellagic acid-loaded microsponges impregnated with chitosan-guar gum hydrogel and evaluate its potential as novel carrier system for wound therapy. Ellagic acid-loaded microsponges were fabricated using ethyl cellulose by the quasi-emulsion solvent diffusion method and incorporated into chitosan and guar gum hydrogel. Prepared microsponges were found to be spherical, non-aggregated particles ranging in size from 100 to 300 µm. The hydrogel formulation was assessed for pharmaceutical characteristics, rheology, drug release, antioxidant and antimicrobial activities. FTIR confirmed that the bioactive and the excipients used are chemically compatible. Spreadability data confirm precise and easy dosage application of microsponge hydrogel in the skin. Results of rheological studies revealed that microsponge-loading considerably increased elastic strength, while frequency and temperature sweep tests demonstrated viscoelastic stability at 25°C. A sustained ellagic acid release for 12 h following the Higuchi kinetics model (R2 = 0.987) was noticed with microsponge loaded chitosan-guar gum hydrogel. The good antioxidant activity exhibited at doses (50-100 µg/mL) by the developed hydrogel implies that the formulation successfully preserves bioactive antioxidant properties. Developed hydrogel retained antimicrobial activity against the test organisms and showed notable inhibition against Pseudomonas aeruginosa at low concentration (12.5 µg/mL). This study establishes an effective topical formulation of ellagic acid-loaded microsponges with potential antioxidant and antimicrobial efficacy, highlighting its possibility to be used for wound healing.