Publicação
Determination of the stability of cosmetic formulations with incorporation of natural products
| Resumo: | Nowadays, natural products are gaining increased popularity as cosmetic ingredients due to their active properties and the different roles they can play in a single cosmetic formula, acting as moisturizers, fragrances, surfactants and preservatives. The aim of this study is to formulate and subsequently evaluate the stability of an anti-aging gel based on natural products namely, bee pollen and essential oils from two species of thymus, Portuguese species Thymus zygis subsp zygis and Tunisian species Thymus capitatus applied as natural preservatives. The stability of the cosmetic formulations was evaluated through a series of physicochemical assays, such as pH, density and viscosity determinations, thermic stress tests, evaluation of the organoleptic characteristics (odor, color and general aspect), UV spectrophotometric analysis, centrifuge test, test of vibration, and also through light test. The formulation also evaluated for its resistance and activity against a variety of microorganisms such as: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. The microbiological stability of the formulations was evaluated through agar diffusion assays using cultures of Escherichia coli, Staphylococcus aureus, Candida albicans, and Pseudomonas aeruginosa. The safety of the formulations were evaluated through the determination of the acute toxicity of the compounds incorporated in the base formulation using brine shrimp (Artemia salina) mobility assay and also through the evaluation of their ocular irritancy using Hen's egg-test on the chorioallantoic membrane test (HET-CAM test). The cosmetic formulations prepared presented a pH value that seems adequate for topic application, and presented a non-Newtonian flow behaviour (shear thinning), which is frequently observed in cosmetic products, besides evidencing no phase separation after centrifuge except the formulation containing methylparaben and bee pollen. No phase separation in all the formulations tested during the vibration test. Organoleptic stability of the formulations was achieved during 2 weeks. The results presented in this study showed good stability throughout the experimental period. All the formulations tested showed a good physical and chemical stability. In addition, the findings suggested that the gel formulations with higher concentration of thyme oils and/or methylparaben have apromising antibacterial Abstract xiii effect against the proliferation of various microorganisms namely S. aureus, P. aeruginosa, E. coli and C. albicans evidencing bacteriostatic effect. S. aureus was the most sensitive bacteria with an inhibition zone ranging from 10 to 25 mm. Moreover, it was observed that the formulations in which bee pollen and thyme oils were incorporated did not caused any irritant reaction on the chorioallantoic membrane of chicken embryo. Also, the previous cited products did not show a toxic effect through Artemia assay with LC50 higher than 1mg/mL (1.88 g/mL, 1.94 g/mL, and 17.78 g/mL for Thymus zygis zygis essential oil, Thymus capitatus essential oil, and for bee pollen, respectively). Therefore, the tests performed suggested that the various cosmetic formulations prepared through the incorporation of bee pollen, Thymus zygis zygis and Thymus capitatus essential oils present characteristics suitable for topic use. Also, the incorporation of the natural products did not seem to influence negatively the stability of the cosmetic formulations. During the present work, it was consistently observed a fungal contamination of the cosmetic formulations based on bee pollen. Different methodologies, such as aseptic practices, freeze-drying and heat treatment were used to overcome it. However only by increasing the preservatives concentration, a decrease in fungi growth was registered. |
|---|---|
| Autores principais: | Bouranen, Amira |
| Ano: | 2017 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Instituto Politécnico de Bragança |
| Idioma: | espanhol |
| Origem: | Biblioteca Digital do IPB |
| Resumo: | Nowadays, natural products are gaining increased popularity as cosmetic ingredients due to their active properties and the different roles they can play in a single cosmetic formula, acting as moisturizers, fragrances, surfactants and preservatives. The aim of this study is to formulate and subsequently evaluate the stability of an anti-aging gel based on natural products namely, bee pollen and essential oils from two species of thymus, Portuguese species Thymus zygis subsp zygis and Tunisian species Thymus capitatus applied as natural preservatives. The stability of the cosmetic formulations was evaluated through a series of physicochemical assays, such as pH, density and viscosity determinations, thermic stress tests, evaluation of the organoleptic characteristics (odor, color and general aspect), UV spectrophotometric analysis, centrifuge test, test of vibration, and also through light test. The formulation also evaluated for its resistance and activity against a variety of microorganisms such as: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. The microbiological stability of the formulations was evaluated through agar diffusion assays using cultures of Escherichia coli, Staphylococcus aureus, Candida albicans, and Pseudomonas aeruginosa. The safety of the formulations were evaluated through the determination of the acute toxicity of the compounds incorporated in the base formulation using brine shrimp (Artemia salina) mobility assay and also through the evaluation of their ocular irritancy using Hen's egg-test on the chorioallantoic membrane test (HET-CAM test). The cosmetic formulations prepared presented a pH value that seems adequate for topic application, and presented a non-Newtonian flow behaviour (shear thinning), which is frequently observed in cosmetic products, besides evidencing no phase separation after centrifuge except the formulation containing methylparaben and bee pollen. No phase separation in all the formulations tested during the vibration test. Organoleptic stability of the formulations was achieved during 2 weeks. The results presented in this study showed good stability throughout the experimental period. All the formulations tested showed a good physical and chemical stability. In addition, the findings suggested that the gel formulations with higher concentration of thyme oils and/or methylparaben have apromising antibacterial Abstract xiii effect against the proliferation of various microorganisms namely S. aureus, P. aeruginosa, E. coli and C. albicans evidencing bacteriostatic effect. S. aureus was the most sensitive bacteria with an inhibition zone ranging from 10 to 25 mm. Moreover, it was observed that the formulations in which bee pollen and thyme oils were incorporated did not caused any irritant reaction on the chorioallantoic membrane of chicken embryo. Also, the previous cited products did not show a toxic effect through Artemia assay with LC50 higher than 1mg/mL (1.88 g/mL, 1.94 g/mL, and 17.78 g/mL for Thymus zygis zygis essential oil, Thymus capitatus essential oil, and for bee pollen, respectively). Therefore, the tests performed suggested that the various cosmetic formulations prepared through the incorporation of bee pollen, Thymus zygis zygis and Thymus capitatus essential oils present characteristics suitable for topic use. Also, the incorporation of the natural products did not seem to influence negatively the stability of the cosmetic formulations. During the present work, it was consistently observed a fungal contamination of the cosmetic formulations based on bee pollen. Different methodologies, such as aseptic practices, freeze-drying and heat treatment were used to overcome it. However only by increasing the preservatives concentration, a decrease in fungi growth was registered. |
|---|