Banca de QUALIFICAÇÃO: CAMILA SOARES DE FRANÇA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : CAMILA SOARES DE FRANÇA
DATE: 23/02/2021
TIME: 08:00
LOCAL: Videoconferência
TITLE:

CHARACTERIZATION OF PROMISING ANTIOXIDANTE NITROXIDES

KEY WORDS:

nitroxides; antioxidants; thermal techniques; non-thermal techniques; factorial planning.

PAGES: 95
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUMMARY:

Nitroxides are a class of molecules with a promising potential in the cosmetic industry due to their antioxidant actions that allow the use in the treatment of skin aging by inhibiting the action of free radicals and, consequently, reducing the effects of skin aging. In this work, three substances belonging to the nitroxide class: TEMPOL, BENZITEMPOL and TSTEMPOL were characterized in terms of physical-chemical aspects, using different analytical techniques, such as: Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry (TG) and developed an indicative method of stability by ultra-efficient liquid chromatography (UHPLC). With the results of the XRD and FTIR techniques it was possible to identify the crystalline nature of these molecules, in addition to confirming the presence of the expected functional groups for the structure of these compounds. Thermoanalytical techniques make it possible to know the thermal behavior of these three nitroxides and for this purpose four heating ratios (5, 10, 15 and 20 °C.min-1) were used, in the temperature range of 25 to 900ºC for TG and 25 to 400 ºC for DSC, both under nitrogen atmosphere at 50 mL.min-1. TEMPOL, BZTEMPOL and TSTEMPOL presented a melting point of 72,2, 121 and 108,4ºC, respectively and the compound that had the greatest thermal stability was TEMPOL at 152° C. In addition to the characterization, a Box-Behnken factorial design was carried out in order to develop an UHPLC method optimized for individually quantifying these molecules. Thus, this study provides useful subsidies for the development of possible cosmetic formulations with these compounds in a safe, effective and quality manner.

BANKING MEMBERS:
Externo à Instituição - DIOGO TEIXEIRA CARVALHO - UNIFAL-MG
Externo à Instituição - FÁBIO SANTOS DE SOUZA - UFPB
Presidente - 1714294 - MARCIO FERRARI