Desenvolvimento e estudo da estabilidade de emulsões com propriedades repelentes naturais

Abstract

Brazil is a country with rich biodiversity, where their essential oils are widely used in cosmetic and pharmaceutical industry. The main goal of this work was to develop and evaluate the emulsion stability, and the incorporation of essential oils.The emul-sions were given a choice to develop a more acceptable pharmaceutical form to a repellent with natural properties with crabwood and citronella. During the study sev-eral formulations were made until come up with the final result with the most appro-priate components. The stability of two emulsions, cream and gel-cream, were measured in the following physic-chemical parameters: centrifugation, cycles of freezing and thawing, density, spreadability determination and pH, besides sensory characteristics. The pH and spreadability tests were statistically evaluated by ANOVA - Post test: Tukey. During the study, the cream characteristics were not constant, forming a stiff upper layer at high temperatures. The density had no significant changes and the pH has changed, however were as recommended for the skin. The spreadability tended to increase from the beginning to the end of tests both cream and gel-cream, however cream had a greater spreadability. In the cycles of freezing and thawing only the cream had a hint of instability, not confirmed by the sample cen-trifugation. For the gel-cream the pH remained stable, but not the ideal for the skin. In both centrifugation as cycles of freezing and thawing test the sample remained sta-ble. The density has changed, but nothing significant. With this study we could notice that the incorporation of Crabwood and Citronella essential oils for both creams as gel-cream systems is possible and the gel-cream formulation were more stable, but additional tests and a longer study is needed for commercialization. The cream has the need for the same requirements in addition to a reformulation to solve the prob-lems identified.