Determination of optimal cream formulation from long-term stability investigation using a surface response modelling

Comparison of sensory and rheological properties of green cosmetic creams prepared on different natural, ECOCERT and BDIH certificated self-emulsifying bases

The objective of this paper was to evaluate and compare the rheological and sensory properties of six natural cosmetic creams that use ECOCERT certificated emulsifying bases: Beautyderm, Dub Base Expert, Simulgreen™ 18-2, Olivem 1000, Montanov L and Emulgin Succro against two synthetics: Granthix APP and Lanette W.

The use of emulsifying bases in formulas helps to stabilize the product and improve its rheological and sensory attributes. In this study, the physical and chemical properties of several prepared cosmetic creams were determined. Apparent viscosity and thixotropy were evaluated by viscosimeter, while spreadability was ascertained by extensometer. Moreover, a group of 10 trained members evaluated the sensory properties of the formulas. The obtained formulas based upon natural emulsifiers are characterized by very good physical and chemical properties, high stabilization and good usage quality. The results were confirmed by sensory analysis. The cosmetic creams made with synthetic emulsifying bases were rated the worst by the study participants, which correlated with the physical tests.

Stress response and characterization of oil-in-water emulsions stabilized with Kluyveromyces marxianus mannoprotein

This study was intended to investigate physico-chemical, rheological, and emulsifying properties of oil-in-water emulsions prepared from the Kluyveromyces marxianus mannoprotein (KMM). Also, the stress-response function of the KMM emulsions was compared with that of the whey protein concentrate (WPC) emulsions in terms of zeta potential, size, and rheology. The stress experiments were conducted at different pH (3 to 9), ionic composition (0 to 500 mM NaCl), and temperatures (30 to 90 °C). The extracted KMM with a molecular weight of 107.2 kDa had 28.8% proteins and 68.22% carbohydrates. With increasing the KMM concentration to 1.5% (w/w), the zeta potential, droplet size, and apparent viscosity of the emulsions reached -35 mV, ∼1 μ, and ∼9 mPa·s, respectively. After applying pH, ionic composition, and temperature, the KMM emulsions were more stable than the WPC emulsions. In conclusion, KMM can be used as a bioemulsifier and be more effective in stabilizing emulsions than WPC. PRACTICAL APPLICATION: Yeasts are a rich source of natural materials. In this study, we extracted mannoproteins from the yeast cell wall and evaluated their functional properties to be used as an emulsifier in oil-in-water emulsions. The results of this study confirm that the yeast-derived mannoproteins are good at stabilizing these emulsions either in the presence or absence of different environmental conditions.

An approach to enhanced stability: Formulation and characterization of Solanum lycopersicum derived lycopene based topical emulgel

Focus of the study was to design a novel and cost effective extraction technique for the lycopene from Lycopersicum esculentum L. fruit and to develop and characterize a stable emulgel formulation containing lycopene as an active ingredient as well as to design an analytical method to determine lycopene concentration in emulgel. Emulgel formulation was prepared and evaluated for its stability at different storage conditions, 8 °C, 25 °C, 40 °C, 40 °C + 75% relative humidity (RH) and 50 °C, for 6 months. Results were statistically analyzed using two way ANOVA, Post-Hoc test and paired sample t-test at 5% significance level. Designed extraction technique presented comparable yield, 154.83 mg/Kg of tomato fruit, with all recoveries in the range of 145-156 mg/Kg of tomato. "P-values" calculated for different levels of stability parameters were <0.05, except at 50 °C and time points of 60th day and later. Analytical method designed was having linear range of lycopene 1-10 µg/mL with limit of detection 0.11 µg/mL and limit of quantification 0.34 µg/mL. All inter-day and intra-day recoveries were in the range of 94-105% while in all measurements RSD % was ≤5.36. It can be concluded that the extraction technique was cost effective with comparable results and analytical method was simple, robust, specific and sensitive enough to be used for lycopene concentration determination in emulgel formulation. Furthermore, designed formulation was stable even at high temperature of 40 °C and RH 75%.

Validation of HPLC-UV Assay of Caffeic Acid in Emulsions

An accurate, sensitive, precise and rapid reversed-phase high-performance liquid chromatographic method was successfully developed and validated for the determination of caffeic acid (CA) in emulsions. The best separation was achieved on a 250 × 4.6 mm, 5.0 µm particle size RP18 XDB Waters column using ethanol and purified water (40:60 v/v) adjusted to pH 2.5 with acetic acid as the mobile phase at a flow rate of 0.7 mL/min. Ultraviolet detection was performed at 325 nm at ambient column temperature (25°C). The method was linear over the concentration range of 10-60 µg/mL (r(2) = 0.9999) with limits of detection and quantification of 1.44 and 4.38 µg/mL, respectively. CA was subjected to oxidation, acid, base and neutral degradation, as well as photolysis and heat as stress conditions. There were no interfering peaks at or near the retention time of CA. The method was applied to the determination of CA in standard and pharmaceutical products with excellent recoveries. The method is applicable in the quality control of CA.

Production and characterization of cosmetic nanoemulsions containing Opuntia ficus-indica (L.) mill extract as moisturizing agent

This study aimed to produce and characterize an oil in water (O/W) nanoemulsion containing Opuntia ficus-indica (L.) Mill hydroglycolic extract, as well as evaluate its preliminary and accelerated thermal stability and moisturizing efficacy. The formulations containing 0.5% of xanthan gum (FX) and 0.5% of xanthan gum and 1% of Opuntia ficus-indica MILL extract (FXE) were white, homogeneus and fluid in aspect. Both formulations were stable during preliminary and accelerated stability tests. FX and FXE presented a pH compatible to skin pH (4.5–6.0); droplet size varying from 92.2 to 233.6 nm; a polydispersion index (PDI) around 0.200 and a zeta potential from −26.71 to −47.01 mV. FXE was able to increase the water content of the stratum corneum for 5 h after application on the forearm. The O/W nanoemulsions containing 1% of Opuntia ficus-indica (L.) Mill extract presented suitable stability for at least for 60 days. Besides, this formulation was able to increase the water content of stratum corneum, showing its moisturizing efficacy.