Banca de QUALIFICAÇÃO: HERYKA REGINA ABRANTES DA COSTA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : HERYKA REGINA ABRANTES DA COSTA
DATE: 20/11/2023
TIME: 14:00
LOCAL: Google meet
TITLE:

Electrochemical sensor based on cerium molybdate and carbon nanotubes for evaluating the thermo-oxidative stability of azithromycin

KEY WORDS:

azithromycin, thermo-oxidative stability, cerium molybdate, carbon nanotube, electrochemical sensor, electroanalytical method.

PAGES: 64
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUMMARY:

Azithromycin (AZT) is among the most successful and highly prescribed antibiotics in the world, being used in first-line treatment for respiratory tract infections, sexually transmitted diseases, dermal infections, and other bacterial manifestations. However, when it is necessary to measure the levels of this active ingredient in complex matrices, or even when you want to study the reactivity and stability of the molecule, the number of analytical possibilities with the necessary requirements for these purposes is still limited. In this work, an innovative proposal was developed with an electrochemical sensor based on cerium molybdate (Ce₂(MoO₄)₃) and multi-walled carbon nanotubes (MWCNT) integrated into a conductive carbon paste. Despite the high reactivity of the materials present in the resulting device (Ce₂(MoO₄)₃-MWCNT/EPC) to analyze the oxidation of the antibiotic, experimental data and computational simulations revealed that the solubility and electroactivity of the antibiotic improve in alkaline electrolyte (pH = 8) prepared in a binary mixture of CH₃OH/H₂O (10:90%, v/v). The charge transfer resistance and, consequently, the sensitivity of the device also improved after the heat treatment of Ce₂(MoO₄)₃-MWCNT/EPC, as a way to eliminate the reticular water contained in the molybdate microcrystals. There is evidence that the oxidation of the antibiotic on the electrochemical sensor occurs irreversibly, losing 2e^‒ of desosamine. After optimizing the electroanalytical parameters, it was possible to detect AZT with a detection limit of 230 nm, in addition to high precision of the results, demonstrated by results deviations below 4.5%. The device showed applicability to evaluate the thermo-oxidative stability of AZT under varying conditions of temperature, ultraviolet radiation and atmospheric air saturation. The results strengthened the idea that quality control of AZT-based medicines must be carried out continuously, using non-ideal laboratory standards and closer to those observed during transport, storage and administration of the products, as a way of making a more rigorous assessment of the validity and viability of the active ingredient in formulations, as well as ensuring the health of consumers.

COMMITTEE MEMBERS:
Externo à Instituição - VALKER ARAÚJO FEITOSA
Externo à Instituição - FRANCISCO WIRLEY PAULINO RIBEIRO
Interno - HEBERTY DI TARSO FERNANDES FACUNDO
Externa à Instituição - MARIA APARECIDA SANTIAGO DA SILVA
Presidente - THIAGO MIELLE BRITO FERREIRA OLIVEIRA