Development of methodologies for dimethylaminoethanol glycolate assay in association with sunscreens in dermocosmetic formulation

Potential of the Ethyl Acetate Fraction of Padina boergesenii as a Natural UV Filter in Sunscreen Cream Formulation

Brown seaweeds, due to their wide range of bioactive compounds, have a high ability to inhibit free radicals and protect against ultraviolet rays. In the present study, the ethyl acetate fraction (EF) was isolated from the Padina boergesenii brown seaweed. Antioxidant activity (by the DPPH scavenging activity method) and cytotoxicity against UVB-induced cytotoxicity in HaCaT human keratinocytes were evaluated. Then, this fraction was used as a bio-filter in the formulation of sunscreen, and the physical properties and stability were investigated. The results showed that the EF could inhibit DPPH radical scavenging (54 ± 1%) and cell viability of HaCaT keratinocytes exposed to UVB irradiation (81.2 ± 0.1%). The results of the stability study of the cream formulated with EF showed that at temperatures 4 °C and 25 °C it has high stability; and at 40 °C on the 28th day, a slight decrease in its stability was observed. The pH and Sun Protection Factor of the cream formulated with EF were reported at 5.8 and 20.55, respectively. Also, the DPPH scavenging activity of the cream was not altered for 28 days of storage at temperatures of 4-40 °C. According to our results, it was proved that the sunscreen formulated with EF of P. boergesenii brown seaweed has promising properties and characteristics that can create a new opportunity for the development of cosmetics and skin care products.

Unplanned absorption of sunscreen ingredients: Impact of formulation and evaluation methods

Permeation of sunscreens agents reduces its effectiveness and safety, leading to systemic circulation and causing unknown adverse effects. In order to maintain the sunscreen efficacy and safety, the filters must stay on the skin surface, with minimum penetration through dermis. Even facing the possibility of filters permeation, the use of sunscreen is important to avoid skin damage as erythema, free-radicals formation, skin ageing and skin cancer, caused by ultraviolet radiation. Aiming potential side effects caused by topical absorption of sunscreens, studies are carried to improve formulation characteristics and stability, reduce skin permeation and evaluate sun protections factor (SPF). Current assays to detect the permeation of sunscreens involve in vivo or in vitro studies, to simulate physiological conditions of use. The aim of this review is to revisit sunscreen skin permeation data over the last decade and the factors that can enhance skin permeation or improve the sunscreen efficacy.

Fabrication, physicochemical characterization and preliminary efficacy evaluation of a W/O/W multiple emulsion loaded with 5% green tea extract

Complex multiple emulsions have an excellent ability to fill large volumes of functional cosmetic agents. This study was aimed to encapsulate large volume of green tea in classical multiple emulsion and to compare its stability with a multiple emulsion without green tea extract. Multiple emulsions were developed using Cetyl dimethicone copolyol as lipophilic emulsifier and classic polysorbate-80 as hydrophilic emulsifier. Multiple emulsions were evaluated for various physicochemical aspects like conductivity, pH, microscopic analysis, rheology and these characteristics were followed for a period of 30 days in different storage conditions. In vitro and in vivo skin protection tests were also performed for both kinds of multiple emulsions i.e. with active (MeA) and without active (MeB). Both formulations showed comparable characteristics regarding various physicochemical characteristics in different storage conditions. Rheological analysis showed that formulations showed pseudo plastic behavior upon continuous shear stress. Results of in vitro and in vivo skin protection data have revealed that the active formulation has comparable skin protection effects to that of control formulation. It was presumed that stable multiple emulsions could be a promising choice for topical application of green tea but multiple emulsions presented in this study need improvement in the formula, concluded on the basis of pH, conductivity and apparent viscosity data.