Avaliação da estabilidade preliminar e atividade antioxidante de Ginkgo biloba L. em matéria - prima e produto acabado.

Abstract

The use of Ginkgo biloba L. (Gb) extracts have been proposed in topical fonnulations for prevention and treatment of the damages caused by free radicais, due this extract has high flavonoid content, adding benefit to the compounding product. Such advantages justify tbeir use by the cosmetic industry, however, there is a need for scientific studies to ensure that these extracts bave actívíty and tberapeutic efficacy after incorporation into creams. Studies involving the stability of Ginkgo biloba L. extract in raw material and incorporated in cosmetic emulsions are rare in literature, being a large part of the studies referring to oral administration phytotherapy, which limits tbe amount of reference data for comparison. Given the above, the aim of this research was determining in vitro the antioxidaot activity of Ginkgo blloba L. in glycolic and dry extract using the free radical scavenging activity on DPPH (2,2- diphenyl-1-picrylhydrazyl), verify if it has activity when incorporated into the pharmaceutical fonn cream and with this conduct the study ofpreliminary stability tbrough physical-chemical tests (pH, spreadability, viscosity, centrifugation and microscopic analysis) to detennine their

bebavior against environmental conditions. The formulations were stable against the physical- cbenúcaJ stability tests. However, after incorporation in the creams, the extracts of Gb

presented instability against antioxidant efficacy, being observed a greater loss in those containing Gb glycolic extract. The results point tbe feasibility of using Gb dry extract in cosmetics of topical use since all the formulations added to this extract, even after thermal stress, presented antioxidant activity within the pharmacopeia parameters. Thus, the microencapsulation ofthe extracts is suggested in order to ensure greater bioavailabWty ofthe active aft.er incorporation in cosmetic producrs, as well as during storage.