MEDJAJI, IntissarBENNABI, Lamia2025-07-102025-07-102025http://dspace.univ-temouchent.edu.dz/handle/123456789/6543In this study, a therapeutic emulgel was formulated using alginate extracted from the brown seaweed Dictyota dichotoma. The main objective was to evaluate the potential of this alginate as a natural gelling agent in a topical formulation with anti-inflammatory and antimicrobial properties. The extracted alginate was characterized using various analytical techniques. Infrared spectroscopy (IR) confirmed the presence of the functional groups typical of alginate. Differential scanning calorimetry (DSC) showed good polymer stability, while X-ray diffraction (XRD) revealed a crystalline structure with calcite crystals present.The formulated emulgel, named Algaflam, was evaluated for its in vivo anti-inflammatory and antimicrobial activities. Another formulation, the reparative ointment AGANAT, based on essential oils of Figel and rosemary (Romarion), was also tested. AGANAT was found to be non-irritating and caused no redness. Both formulations showed highly promising results compared to the controls. Rheological analysis indicated that the product exhibits pseudoplastic shear-thinning behavior, which is favorable for topical application, in addition to a stable and pleasant texture. When compared to an emulgel of similar composition made with commercial alginate, the results suggest that alginate extracted from Dictyota dichotoma is a valuable biomolecule for pharmaceutical applications, especially in topical delivery systems.frAlginate, algue brune,inflammation , etude rheologique , bactérieAlginate, brown algae, inflammation, rheological study, bacteria.Thesis