Physical chemistry evaluation of stability, spreadability, in vitro antioxidant, and photo-protective capacities of topical formulations containing Calendula officinalis L. leaf extract

Abstract

Calendula is used widely in cosmetic formulations that present phenolic compounds in their chemical constitution. The objective of our research was to develop and evaluate the stability of topical formulations containing 5% hydro-ethanolic extract of calendula leaves, including spreadability, and in vitro photo-protective, and antioxidant capacity. To evaluate the stability, we used organoleptic characteristics, pH, and viscosity parameters. Antioxidant capacity was measured by the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, and the photo-protective capacity by SPF spectrophotometric measure. All formulations were stable. The calendula extract formulations in gel and cream showed no significant variations in pH, and the cream formulations presented lower viscosity variations than gel formulations. The spreadability of the gel formulations was superior to those in cream. The formulations also presented good antioxidant capacities and an FPS of around 1.75. In accordance with the results, the formulations can be used as antioxidants, but considering the low SPF obtained, calendula cannot be considered as a stand-alone sunscreen, yet may well be tested in future studies towards verifying enhancement of synthetic sunscreens.

Fragaria vesca L. Extract: A Promising Cosmetic Ingredient with Antioxidant Properties

“…The changes in viscosity results are in accordance with previous results. The values varied from 12,000 to 31,000 mPa s. These variations were expected since, normally, viscosity is directly influenced by temperature variations [32]. Sample S1, stored at room temperature in the light, showed an evident degradation of the compounds, as revealed by organoleptic analysis, as well as a decrease in viscosity.…”

“…These results, as well as the ones obtained in the organoleptic analysis, where the appearance and color of the formulation changed, strongly suggest that in this sample the properties of the extract were altered. Elevated temperatures can accelerate chemical reactions, altering the activity of the components, viscosity, appearance, color, formulation odor and flavor, and leading to the degradation of phenolic compounds, since these are sensitive to hydrolysis [32].…”

Desenvolvimento E Estudo De Estabilidade Físico-Química De Formulações Cosméticas Antienvelhecimento

“…Da mesma forma, notou-se que as formulações armazenadas em alta temperatura foram as que mais sofreram alterações em suas viscosidades. Piana et al (2013), Coelho et al (2016), Fialho et al (2017), Deuschle et al (2015) e Deuschle et al (2018) também observaram maiores variações de viscosidade em suas formulações mantidas em temperaturas elevadas.…”

Multifunctional photoprotection: corrective makeup for cutaneous dyschromias

“…Spreadability can be defined as the expansion of a formulation on a surface after a certain period of time, and it is closely linked to applying these formulations at the site of action. Therefore, sunscreens should allow easy spreading on the skin to ensure nominal SPF (Nesseem, 2011;Deuschle et al, 2015). The results are presented in Table XVI, where MD is the mean diameter.…”