Banca de QUALIFICAÇÃO: ELMAR DAMASCENO JUNIOR

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : ELMAR DAMASCENO JUNIOR
DATE: 21/02/2024
TIME: 09:00
LOCAL: videoconferência
TITLE:

Obtaining nanohybrids from montmorillonite for application in the modified release of drugs.

KEY WORDS:

tuberculosis; rifampicin; isoniazid; montmorillonite; nanohybrid; pH-responsive system

PAGES: 70
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Analítica
SPECIALTY: Separação
SUMMARY:

Systems based on clay-drug nanohybrids have been widely reported in the literature, showing interesting characteristics that have increased the bioavailability of various biomolecules, such as increased solubility of hydrophobic drugs, protection against degradation along the gastrointestinal tract, controlled and pH-responsive release. The main objective of this work is to obtain clay/drug and clay/polysaccharide/drug nanohybrids for application in the modified release of drugs, with the aim of improving the therapeutic efficacy of drugs that have severe side effects associated with their administration. Montmorillonite, because it has good adsorption capacity, a considerable specific surface area and excellent cation exchange capacity (CEC), was applied in its natural form, without any modification, and associated with a polysaccharide. The polysaccharides used were carboxymethylcellulose (CMC) and a polysaccharide extracted from chia seeds (Salvia hispânica L.). The carrier system obtained was associated with two tuberculostatic drugs, isoniazid (INH) and rifampicin (RIF). The first stage of the work consisted of obtaining the montmorillonite-rifampicin nanohybrid and applying it to the pH-responsive release of the tuberculostatic drug. A 2⁴-factor design was used to evaluate the influence of operational variables on the drug incorporation process. The experiment under optimized conditions yielded an incorporated drug dose equivalent to 98.60 ± 1.21 mg/g. The hybrid systems were characterized using different techniques (FTIR, XRD, TGA, DSC) to elucidate the mechanism of interaction between the compounds used. Through in vitro release studies, it was possible to verify the effectiveness of the pH-dependent system obtained, with approximately 70% of the drug being released after 16 hours in simulated intestinal fluid. The fit of the experimental release data to Higuchi's theoretical model indicated that the release of rifampicin occurs in a prolonged manner from montmorillonite. The elucidation of the interactions between the drug and this clay mineral reinforces its viability as a new carrier for developing an anti-TB/clay hybrid system with good physical and chemical stability.

COMMITTEE MEMBERS:
Externa ao Programa - 1412709 - NEDJA SUELY FERNANDES - nullPresidente - 2413537 - POLLYANA SOUZA CASTRO
Externa à Instituição - RAQUEL DE MELO BARBOSA - US