Banca de QUALIFICAÇÃO: DOUGLAS DOURADO OLIVEIRA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : DOUGLAS DOURADO OLIVEIRA
DATE: 20/01/2021
TIME: 15:30
LOCAL: DEFESA REMOTA - https://meet.google.com/afk-pqsw-cez
TITLE:

MICROEMULSION-BASED ORGANOGEL NANOPARTICLES: A PROMISSING APPROACH FOR CURCUMIN DELIVERY

KEY WORDS:

Organogel; low molecular weight; curcuminoids; nanotechnology; oral administration.

PAGES: 120
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUBÁREA: Farmacotecnia
SUMMARY:

Curcumin is a polyphenol obtained from the rhizome of Curcuma longa, popularly known as turmeric. In this rhizome, 3 to 5% curcuminoids are present, with curcumin being the major component, which has stood out due to its low in vivo toxicity and high biological potential. However, curcumin is classified by the biopharmaceutical classification system as a class IV molecule, (low water solubility and low permeability), which compromises its bioavailability in a physiological environment. Additionally, this molecule is susceptible to intense metabolism, being rapidly eliminated, in addition to presenting instability in gastrointestinal pH. Thus, the objective of this thesis was to develop, characterize the physicochemical, thermal properties and evaluate the stability in different approaches of a microemulsion containing curcumin, the base system for obtaining organogel nanoparticles for oral use. For this, a pseudo-ternary phase diagram was initially developed using the water titration method to obtain microemulsion regions (ME), whose systems were emulsified by ultrasound. An oil in water (O / W) formulation with a lower concentration of surfactants and a satisfactory oil phase for encapsulating curcumin was selected. Curcumin was encapsulated according to the emulsification methodology used for the empty microemulsion. MEs were characterized in terms of droplet size distribution, electrical conductivity, surface tension, rheology, morphology, thermal profile and encapsulation efficiency, determined by Ultra High Performance Liquid Chromatography (UHPLC). In addition, the long-term stability of the MEs and resistance to simulated gastrointestinal fluid were determined. The data revealed the obtaining of ME (drug-free) and Curc-ME (containing curcumin) with a total of 15% surfactants, which directly impacted the amount of drug incorporated. Furthermore, the systems revealed physicochemical characteristics suitable for a microemulsion, with monomodal and spherical droplet size distribution (22 ± 0.2 nm and PdI of 0.09 ± 0.07 for ME and 22 ± 0.7 nm, PdI 0.07 ± 0.01 for Curc-ME), electrical conductivity values characteristic of O / W systems (206 ± 6 μS cm ^{- 1} for ME, 160 ± 3 μS cm ^{- 1} for Curc-ME), low apparent viscosity (2 x 10 ^-3 ± 0.02 Pa.s for ME and 5.3 x 10^-3 ± 0.01 Pa.s for Curc-ME) and low surface tension (40.75 ± 0.41 dynes / cm for ME and 40.37 ± 0.48 dynes / cm for Curc-ME). The thermal profile was suggestive of encapsulation of curcumin, confirmed by its quantification in UHPLC (98% ± 0.73). Moreover, MEs were stable over 90 days as well as against simulated gastric and intestinal fluids. In view of this, Curc-ME proved to be a potential carrier for the oral route, given the low concentration of surfactants and attested in vitro gastroresistance, Finally, the system showed favorable characteristics to act as a starting system for the obtaining of organogel nanoparticles, the desired final carrier in this thesis.

BANKING MEMBERS:
Externo ao Programa - 1639820 - ARNOBIO ANTONIO DA SILVA JUNIOR
Presidente - 1178187 - ERYVALDO SOCRATES TABOSA DO EGITO
Externo à Instituição - FRANCISCO HUMBERTO XAVIER JUNIOR - UnP