Development of a photoprotective and antioxidant nanoemulsion containing chitosan as an agent for improving skin retention

Abstract

Sunscreens are destined to topical application and should protect skin against ultraviolet radiation; furthermore, they are toxic substances and should not reach the bloodstream, so they must be retained in the skin. In the present work, an oil-inwater photoprotective and antioxidant nanoemulsion (NE) containing chitosan was developed. Preliminary studies were performed aiming to choose the surfactant to be used in this NE; stability of the formulas was determined by dynamic light scattering after their preparation and after 7 days. A blend of surfactants, polyoxyethylene sorbitan monooleate, and sorbitan monooleate was selected for the preparation of the NE, as well as the following organic sunscreens: benzophenone-3, diethylamino hydroxybenzoyl hexylbenzoate, octocrylene and octylmethoxycinnamate, and also pomegranate antioxidant extract and chitosan. The antioxidant extract with the highest antioxidant activity was chosen based on a screening of plant extracts by DPPH• (2,2-diphenyl-1-picrylhydrazyl) assay. Photostability of the sunscreens and in vitro efficacy and safety of the formulations were also evaluated. Results showed that the developed photoprotective and antioxidant NE containing chitosan was stable for at least 6 months, photostable when irradiated in a solar simulator, and effective. Additionally, chitosan acted by promoting retention of the formulation in epidermis, thus increasing formulation safety.

Multifunctional photoprotection: corrective makeup for cutaneous dyschromias

“…The sunscreen formulations were deposited and evenly overspread on the plates at 1.2 mg/cm 2 (equivalent to 30 mg). After 15 min protected from light, the samples were read and the in vitro SPF values were obtained (Miksa, Lutz, Guy, 2014;Miksa, Lutz, Guy, 2015;Cerqueira-Coutinho et al, 2015). The analysis was carried out in triplicate.…”

“…Physicochemical characteristics, such as phase separation (centrifugation test), density, and pH were also assessed (Anvisa, 2004;Smaoui et al, 2013). The SPF variation of the formulations was also observed during the stability tests (Miksa, Lutz, Guy, 2015;Cerqueira-Coutinho et al, 2015;Mansur et al, 2016).…”

“…SPF variations were evaluated in triplicate by transmittance spectrophotometry with a Labsphere ® (Miksa, Lutz, Guy, 2015;Cerqueira-Coutinho et al, 2015;Mansur et al, 2016).…”

Current application of phytocompound-based nanocosmeceuticals for beauty and skin therapy

“…However, this method has limitations in cosmeceutical production due to instability of emulsions during storage. [149][150][151][152][153][154][155][156][157][158] Further, the emulsion core compounds direct whether a single or multiple nanoemulsions can be formed based on their number of core compounds in the nanosized emulsions. 159,160 Multiple emulsions have advantages over single emulsions, due to their wider applications in cosmeceuticals, which can further reduce cosmeceutical cost.…”

Desenvolvimento e avaliação de nanoemulsão cosmética à base de óleos naturais de urucum (Bixa orellana, L) e café verde (Coffea arabica, L)

“…O tamanho dos glóbulos das nanoemulsões varia entre 20 e 500 nm, ou entre 50 a 1000 nm, dependendo da classificação utilizada pelo pesquisador, porém muitos consideram 500 nm como o limite máximo para o sistema ser considerado como nanoemulsão. O produto final pode ser transparente (permite a passagem da luz e é possível ver nitidamente através da NE) ou translúcido (permite a passagem da luz, mas não permite visualizar através da NE), apresentando-se estável em relação à sedimentação e cremeação(FORGIARINI et al, 2001;ROCHA-FILHO et al, 2014;YUKUYAMA et al, 2015) Os estudos de aplicações de NEs abrangem diversos campos de conhecimento, como alimentos, farmacêutico e embalagens.NEs são estudadas como veículos para a administração de substâncias hidrofóbicas, melhorando sua biodisponibilidade e para direcionar a administração de medicamentos a tecidos específicos ou melhorar o disgnóstico de doenças, através da utilização de ligantes presos à superfície dos glóbulos e o controle do tamanho de partícula(GANTA et al, 2016).No campo da cosmética, as NEs vem apresentando resultados promissores para o desenvolvimento de novos produtos com afinidade pela pele, evitando absorção pela corrente sanguínea(CERQUEIRA-COUTINHO et al, 2015). Também foram observados efeitos como o aumento de hidratação e da concentração de colágeno na pele, em produtos para combater o envelhecimento da pele(NGAN et al, 2015), bem como melhor ação anti-inflamatória, quando comparada com a emulsão convencional, preparadas com o mesmo extrato vegetal(BRESOLIN et al, 2016).A aplicação das NEs no campo da cosmética apresenta a uma série de vantagens, segundo enumera TADROS et al(2004):…”