Banca de DEFESA: JÚLIO ABREU MIRANDA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : JÚLIO ABREU MIRANDA
DATE: 01/08/2026
TIME: 09:00
LOCAL: REMOTA - https://meet.google.com/ixx-cvpb-hse
TITLE:

TECHNOLOGICAL DEVELOPMENT OF LINSEED OIL-BASED NANOEMULSION CONTAINING AVOBENZONE AND TRIS-BIPHENYL TRIAZINE: ANALYTICAL VALIDATION, PHOTOSTABILITY, IN VITRO PHOTOPROTECTION AND EX VIVO SKIN SAFETY

KEY WORDS:

avobenzone; HPLC; linseed oil; nanoemulsion; photoprotection; tris-biphenyl triazine.

PAGES: 100
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUMMARY:

Ultraviolet (UV) radiation is a major risk factor for various skin damages, including skin cancer, making sunscreens a key preventive strategy. In this context, the development of effective and safe sunscreen formulations remains a constant challenge in the cosmetic field. Therefore, this study aimed to develop, characterize, and evaluate in vitro a linseed oil-based nanoemulsion containing the UV filters avobenzone (AVO) and tris-bifenil triazine (TBPT), with a focus on improving AVO photostability, photoprotective efficacy, and skin safety. Initially, an HPLC method was developed and validated for the simultaneous quantification of AVO and TBPT, following the ICH guidelines and employing a Box-Behnken design. A nanoemulsion was then formulated, produced and optimized (NEUVMIXopt), containing 10% of linseed oil, 10% surfactant mixture (Kolliphor® RH 40:Span® 80 8,7:1,3), 1% AVO, 8% TBPT, 1% vitamin E, 0.2% potassium sorbate, 0.5% xanthan gum, and purified water to 100%. This formulation was characterized by transmission electron microscopy and dynamic light scattering, showing spherical morphology, clear distinction between TBPT particles and oil droplets, mean diameter of 147.48 ± 0.58 nm, polydispersity index of 0.23 ± 0.02, zeta potential of -25.09 ± 0.40 mV, and pH of 6.52 ± 0.10, indicating colloidal stability and suitability for topical application. Photostability assays demonstrated a significant increase in AVO half-life, from 39.24 minutes in linseed oil solution to 138.16 minutes in NEUVMIXopt. Furthermore, photoprotective efficacy studies using diffuse reflectance spectrophotometry showed that the developed formulation provided UV protection for all skin phototypes, with SPF values of 21.67 ± 6.67, a UVA/UVB ratio of 0.88 ± 0.01, and a critical wavelength of 381.67 ± 0.43 nm. Skin safety studies using porcine ear skin revealed that the formulation had no transdermal permeation potential, favoring local deposition of UV filters in the outer skin layers. Finally, histological analysis of the treated pig skin showed no morphological changes, indicating the absence of irritant potential. Altogether, these results reinforce the potential of combining nanotechnology with natural oils as a promising strategy for developing more effective and safer sunscreen products.

COMMITTEE MEMBERS:
Externa à Instituição - HÉLEN CÁSSIA ROSSETO - UFMS
Externo à Instituição - DANIEL CRISTIAN FERREIRA SOARES - UNIFEI
Presidente - 1178187 - ERYVALDO SOCRATES TABOSA DO EGITO
Externa ao Programa - 2569445 - LOURENA MAFRA VERISSIMO - nullInterno - 2646619 - RODRIGO PEGADO DE ABREU FREITAS