Banca de DEFESA: TAYNARA MONSORES E SILVA

DEVELOPMENT AND CHARACTERIZATION OF ORAL FORMULATIONS CONTAINING QUERCETIN FOR PROPHYLAXIS OF CANINE PERIODONTAL DISEASE

Canine periodontal disease, Quercetin, Pharmaceutical development.

Periodontal disease (PD) arises from the formation of bacterial biofilm on the surface of teeth and their adjacent tissues. It is characterized as the most prevalent oral condition in humans and animals, being present in approximately 70% of adult dogs. In veterinary medicine, its prevention and treatment are challenging since establishing a hygiene routine is not straightforward, and the persistence of conventional formulations in the oral cavity is hindered by saliva action and mechanical mouth activity. Thus, innovation in this field is essential, especially in the face of bacterial resistance that may be involved in different stages of the disease. In this context, the use of products derived from natural sources becomes an alternative to conventional products, such as flavonoids, which stand out due to their antimicrobial properties and their regenerative action on soft and hard tissues, which make up the oral mucosa. Among them, there are quercetin (QRC) and rutin (RTN), which already have reports showing their antimicrobial activity against sensitive and resistant strains. Therefore, this study aimed to estimate the minimum inhibitory and bacteriostatic concentrations of these two flavonoids against nine strains, both sensitive and resistant, of importance for PD. After the assays, QRC proved to be more promising and was selected as the active molecule for pharmaceutical development tests. The following were developed: a hydrogel (HG) and a carboxymethyl cellulose sodium-based film (CMC-Na) and a chitosan-based HG (CTS). As a result, the formulations maintained a pH range of 6.5 to 7.5, ensuring safety during application, except for the CTS HG, which showed a slightly lower pH than ideal. The content of CMC-Na and CTS HG, as well as the film, was 98.2%, 95.0%, and 97%, respectively. The formulations showed extended residence times, exceeding 5 hours. Regarding in vitro release, the CMC-Na HG exhibited zero-order kinetics and a release rate of 32.1% in 24 hours, while the CTS HG and the polymeric film exhibited pseudo-first-order kinetics with release rates of 18.6% and 26% in 24 hours, respectively. Morphological analyses of the polymeric film revealed pores in the formulations containing QRC and greater compactness in the placebo film. Structural analyses showed that the presence of QRC does not alter the structure of the components present in the film but results in a more intense C=C stretching. The combination of all results indicated that the developed formulations have innovative potential for preventing and treating canine PD.