Silva, Djalma Ribeiro daDamasceno Júnior, Elmar2021-02-022021-02-022020-02-04DAMASCENO JÚNIOR, Elmar. Aplicação da Palygorskita na liberação pH-responsiva de fármacos tuberculostáticos. 2020. 158f. Dissertação (Mestrado em Química) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2020.https://repositorio.ufrn.br/handle/123456789/31362Tuberculosis is the second leading cause of death due to the worsening of an infection in the world. An isoniazid and rifampicin are the first in the heavily affected line in the treatment and prevention of this disease. However, administration of these drugs may cause serious effects, such as peripheral neuropathy, hepatotoxicity and hematotoxicity, resulting from prolonged use of these substances. Thus, it is necessary to search for new release systems for tuberculostatic drugs, in order to avoid unwanted adverse effects, protecting or against gastrointestinal tract degradation, increasing bioavailability and, consequently, improving therapeutic efficacy. The present work studies the pH-responsive systems for INH and RIF, using a palygorskite as nanocarrier, a natural, abundant and low cost material. The incorporation process was evaluated through a factorial design, and finally investigated the influence of some factors on drug adsorption. The experiment using a maximum concentration (0.075 mg/mL for isoniazid and 0.125 mg/mL for rifampicin), lower palygorskite mass (300 mg) and lower pH (pH 2) was the most efficient during the other experiments, resulting in a higher dose of incorporated drug, equivalent to 12.93 mg/g palygorskite for isoniazid and 33.62 mg/g palygorskite for rifampicin. The results obtained by the characterization techniques (Infrared Spectroscopy with Fourier Transform, X-Ray Diffraction, Thermogravimetry/Derivative Thermogravimetry, Differential Scanning Calorimetry, Zeta Potential, Scanning Electron Microscopy and Dispersive Energy Spectroscopy) and the application of kinetic and isothermal models of adsorption, proved the incorporation of the drugs in the clay and helped to elucidate the mechanism of interaction among the materials. Through in vitro release studies carried out with hybrid materials, it was possible to verify the effectiveness of the pHdependent systems obtained for the drugs. More than 60% of the dose, in both cases, was released in the intestinal medium (pH 6.8 and pH 7.4). The kinetic study showed that the zero order model and the Higuchi model was the one that best fitted the experimental data for isoniazid and rifampicin, respectively, indicating that the release occurs in a prolonged way from the palygorskite.Acesso AbertoTuberculoseIsoniazidaRifampicinaSistema pHresponsivoPalygorskitamasterThesis