THERMORESPONSIVE HYDROGELS FOR BUCCAL EUGENOL DELIVERY

The action of drugs on the oral mucosa can be improved through delivery systems that provide longer localresidence time for the treatment of diseases or procedures in the oral cavity. The aim of this study was to developpoloxamer-chitosan hydrogel formulations containing eugenol, based on poloxamer 407 20% (w/w)and chitosan 1% (w/w), namely: poloxamer-hydrogel (HP), poloxamer-chitosan hydrogel (HPQ), poloxamer-chitosan hydrogel with eugenol 1% (w/w) (HPQEU1); poloxamer-chitosan hydrogel with eugenol 2%(w/w) (HPQEU2); and poloxamer-chitosan hydrogel with eugenol 4% (w/w) (HPQEU4). The characterizationwere made by sol/gel transition (Tsol/gel), pH, spreadability, rheology and texture, turbidimetry, drugquantification by UV-Vis spectrophotometry and stability test. The Tsol/gel were 29.33 ± 0.57, 29.66 ± 0.7,25.33 ± 0.57, 19.33 ± 0.57 °C for HP, HPQ, HPQEU1, HPQEU2, respectively. Hydrogels with chitosanexhibited pH of 5.3. HPQEU1 and HPQEU2 showed elastic behavior, spreadability and texture profilesuitable for oral application. The stability study evidenced storage at 5 ± 2 °C as favorable. HPQEU1,HPQEU2 and HPQEU4 were able to adhere to the mucosa evidenced by ex vivo pig cheek model. Thus,thermoresponsive hydrogels may constitute effective alternatives for localized delivery of eugenol to theoral mucosa, a remarkable feature in dental clinical practices.