BIOMETRIA CUTÂNEA COM FORMULAÇÕES SEMISSÓLIDAS CONTENDO NANOCÁPSULAS DE PALMITATO DE ASCORBILA

• Autor(a) principal: Silva, Ana Paula Tasquetto da
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional Universidade Franciscana
• Texto Completo: http://tede.universidadefranciscana.edu.br:8080/handle/UFN-BDTD/201; http://www.tede.universidadefranciscana.edu.br:8080/handle/UFN-BDTD/315
• topic: palmitato de ascorbila; nanocápsulas; biometria cutânea; ascorbyl palmitate; nanocapsules; non-invasive method; CNPQ::ENGENHARIAS

Aging is a natural occurring process in our body, resulting in a series of structural changes in our skin, such as transepidermal water loss, senile xerosis (dry skin) and hyperpigmentation disorders. Vitamin C is a powerful antioxidant and have ability to inhibit melanogenesis, and skin bleaching agent. However, his low stability is a serious limitation. Thus, ascorbyl palmitate (AP), lipid-soluble derivative, appears as a promising agent for incorporation in topical formulations. Thus, this study aim to develop, characterize and determine the physical-chemical stability of topical semisolid formulations containing nanocapsules of the ascorbyl palmitate, with the oily nucleus of the Rosehip oil. Associated to this, the safety of the active in vivo by non-invasive biophysical analysis was verified. Suspensions containing the PA associated to the nanocapsules (NCPA) and suspensions without the active (NCBC) were developed and characterized, and stability was evaluated for 90 days (25 °C ± 2 °C and 3 °C ± 2 °C). Inicially, the NCPA suspensions presented content equal to 82,95 %, pH 4,21, average particle diameter of 269,7 nm, polydispersity index of around 0,2 and zeta potential of -47,03 mV. After, the active in the free form (GPA) and associated to the nanocapsules (GNCPA) were incorporated in semi-solid basis of Carbopol® gel and stored, for 90 days, for stability studies, by determination of the pH, active content quantification, organoleptic characteristics determination, viscosity determination and spreadability. All formulations presented slightly acidic pH and a homogeneous aspect. We obtained a higher concentration of active GNCPA, suggesting that nanocapsules may exert a greater protection of the PA. However, in both formulations in different temperatures, after 90 days analysis a decrease was observed and the GNCPA remain with a higher concentration of PA. Regarding to the rheological behavior, independently of drug dispersion, all formulations showed a non-Newtonian character and pseudoplastic behavior together with an adequate spreadability during the analysis period. For the bioengineering skin measurements, twenty healthy volunteers were selected, and during 90 days, every week, were performed biometric skin tests including stratum corneum water content (hydration), pH, transepidermal water loss, color and erythema. According to the results observed in relation to the determination of skin hydration, there was pronounced reduction (24 %) of the values of the stratum corneum water content in the areas treated with GPA, while GNCPA obtained an increased in hydration (21 %). The skin pH values not change significant during the experiment for both formulations, and this values are into the satisfactory limits for the use in topical products. We observed an increase in transepidermal water loss for both gels, however, to the GPA, this increased was slightly larger (39 %). Thus, it was evident that the nanocapsules have a tendency to avoid the transepidermal water loss, favoring the skin hydration degree and maintain the integrity of the stratum corneum. In the results obtained for melanin content, there was a decrease in this parameter during the experiment for both formulations, being more pronounced in GNCPA (23 %). The GNCPA and GPA did not cause erythema, configuring security in the use of these formulations.