Study of sun protection factor of extracts rich in flavonoids into topical formulation

Author(s)

Letícia Caramori Cefali

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2018-08-31

Examining board members

Priscila Gava Mazzola; André Moreni Lopes; Marlus Chorilli; Guilherme Diniz Tavares; Rodrigo Ramos Catharino

• Advisor: Priscila Gava Mazzola; Mary Ann Foglio

Abstract

The aim of this study was to develop a phytocosmetic containing a blend of enriched flavonoids extracts from natural sources i.e. from Dirmophandra mollis Benth, Ginkgo biloba L., Ruta graveolens L. and Vitis vinífera L.. Individual alcoholic extracts (obtained from each species) and a mixed extract (1:1:1:1) were analyzed by validated HPLC-DAD for the identification of flavonoids and quantification of rutin and quercetin. In vitro cell viability, sun protection factor and antioxidant efficacy studies were carried out. One oil-in-water emulsion was development, mixed extracts (1:1:1:1) was incorporated to formulation (200 µg/ml), named SPF and sun protection factor, antioxidant activity, physicochemical stability, photostability, rheology, texture assay, cutaneous permeation and retention of flavonoids were evaluated. Vegetable extracts were also loaded in nanoparticles, by ionic gelation and its physicochemical properties were evaluated such as morphology, mean particle size, zeta potential and encapsulation efficiency for flavonoids-enriched vegetable extracts. Another oil-in-water emulsion was obtained by dispersing nanoparticles in emulsion (reference to 200 µg/ml of mixed), named SPF-nano. Results showed that the HPLC method used for the identification and quantification of flavonoids in extracts exhibited linearity, precision, accuracy and robustness. All extracts did not affect cell viability at the evaluated concentration range (maximum concentration of 250 ?g/ml) and exhibited sun protection effect and antioxidant activity. Among evaluated extracts, Ginkgo biloba L. and mixed extracts depicted the most expressive results. Mixed extract exhibited sunscreen protection against UVA/UVB and UVAPF value of 6.92 ± 0.1. SPF formulation was stable when stored at low temperatures (5ºC), spreadability, low rupture strength and adhesiveness, higher brittleness, pseudo-plastic and viscoelastic behaviors been that parameters were in accordance for a topical product. SPF formulation presented 17.96 ± 0.03% of inhibition percentage against DPPH solution, 2.4 ± 0.5 value referent to UVA protection, critical wavelength equal 387.0 nm and UVA/UVB rate equal 0.78, determining that the formulation can be used as sun filter with UVA/UVB protection. Photostability was evaluated and UVAPF value decreased 13.04%, being considered a photostable product. Rutin permeated skin barrier and was also found in stratum corneum (3.27 ± 1.92 µg/ml) by tape stripping and retention test (114.68 ± 8.70 µg/ml). Nanoparticles were prepared and presented yellowish color, spherical shape and uniform in their appearance. Extract-loaded nanoparticles showed a mean particle size of 557.11 ± 3.1 nm, polydispersity index (PDI) of 0.39 ± 0.27, zeta potential of -11.54 ± 2.1 mV and encapsulation efficiency of 71.43% in rutin. SPF-nano showed physicochemical stability, photostability and texture parameters appropriate for skin application. Rutin was also permeated skin barrier and was found in stratum corneum (1.26 ± 0.20 µg/ml) and retention test (91.52 ± 3.94 µg/ml), such as occurred to SPF formulation. The recorded UVAPF value was of 2.3 ± 0.4, with a critical wavelength of 387.0 nm, and UVA/UVB rate of 0.69. Then, mixed extract may be a potential alternative over chemical sun filter and phytocosmetics containing free extracts or nanoparticulated reported herein provide with sun protection and promising physical characteristics for a potential sunscreen formulation (AU)

• FAPESP's process: 15/25533-7 - DEVELOPMENT AND EVALUATION OF A FLAVONOID ENRICHED EMULSION WITH SUN PROTECTION FACTOR
• Grantee: Leticia Caramori Cefali
• Support Opportunities: Scholarships in Brazil - Doctorate