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The aim of this study was to evaluate the potential role of burdock and black radish powders in emulsion-type hair conditioners. The studied plant powders were obtained by low-temperature drying. This method allows plants to retain many valuable nutrients, including vitamins or phytosterols, which have a positive effect on the condition of hair and skin. For the selected plant powders, the content of vitamin C and total polyphenolic content, as well as the degree of reduction of DPPH free radicals, were determined. Burdock and black radish powders proved to contain polyphenolic compounds and exhibited antioxidant activity, which is particularly evident in burdock powder. The plant material under study was also proven to contain vitamin C. The following stage of this study involved designing the formulations and preparing seven hair conditioner emulsions containing different plant-based powders at various concentrations. In the next step, the cosmetic prototypes were evaluated for their physicochemical and functional properties. The hair conditioners were found to have satisfactory functional characteristics, including dynamic viscosity, yield stress, and consistency. Colorimetric analysis showed that an increase in the concentration of burdock and black radish powders obtained by low-temperature drying in hair conditioners resulted in a more saturated color compared to the reference sample. The test results indicated that an increase in the concentration of the plant-derived powders contributes to an increase in the intensity of the yellow color of the samples. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the potential role of burdock and black radish powders in emulsion-type hair conditioners. The studied plant powders were obtained by low-temperature drying. This method allows plants to retain many valuable nutrients, including vitamins or phytosterols, which have a positive effect on the condition of hair and skin. For the selected plant powders, the content of vitamin C and total polyphenolic content, as well as the degree of reduction of DPPH free radicals, were determined. Burdock and black radish powders proved to contain polyphenolic compounds and exhibited antioxidant activity, which is particularly evident in burdock powder. The plant material under study was also proven to contain vitamin C. The following stage of this study involved designing the formulations and preparing seven hair conditioner emulsions containing different plant-based powders at various concentrations. In the next step, the cosmetic prototypes were evaluated for their physicochemical and functional properties. The hair conditioners were found to have satisfactory functional characteristics, including dynamic viscosity, yield stress, and consistency. Colorimetric analysis showed that an increase in the concentration of burdock and black radish powders obtained by low-temperature drying in hair conditioners resulted in a more saturated color compared to the reference sample. The test results indicated that an increase in the concentration of the plant-derived powders contributes to an increase in the intensity of the yellow color of the samples.

Technological innovation in the cosmetic field must necessarily consider not only the safety and efficacy requirements but also the growing attention to environmental issues and the need for sensory pleasure during application to satisfy the consumers' expectations. This work aimed to formulate an oil-in-water fluid emulsion stabilized by the combination of organic and inorganic powders, namely Zea mays starch and zinc oxide associated at different ratios in presence of a polysaccharidic rheological modifier. After verifying the physical stability of the prototypes with a mechanical stress test in a centrifuge, the rheological analyses were conducted in continuous and oscillatory flow conditions, and the immersion/de-immersion test, conducted using a texture analyzer, allowed identifying the system with the viscoelastic characteristics and the parameters of textures, such as firmness, consistency, and adhesiveness, more suitable for the formulation of skin-care products with low viscosity and high spreadability. Finally, we studied the compatibility of the powders with sunscreen filters and pigments, to optimize the systems and assess their potential use in finished products. [ABSTRACT FROM AUTHOR]

Objective: Nowadays, the use of silicones in cosmetic formulation is still controversial, given that "natural" or "biodegradable" components are preferred. Often, the exclusion and/or the discrimination of these excipients from cosmetic field are unmotivated because all things cannot be painted with the same brush. Hence, we want to bring to light and underline the advantages of including silicones in cosmetic emulsions, refuting and debunking some myths related to their use. Methods: Silicone‐free and silicone‐based emulsions were obtained within an easy homogenization process. Droplet size distribution was assessed by laser diffraction particle size analyser Mastersizer 2000™, and by optical microscopy. The long‐time stability profiles were investigated thanks to the optical analyser Turbiscan® Lab Expert. Diffusing wave spectroscopy (DWS) by Rheolaser Master™ and frequency sweep measurements by Kinexus® Pro Rotational Rheometer were carried out to assess a full rheological characterization. In vivo studies were carried out by the evaluation of Trans Epidermal Water Loss (TEWL) over time on healthy human volunteers. A skin feeling rating was collected from the same volunteers by questionnaire. Results: From size distribution analysis, a better coherence of data appeared for silicone‐based emulsion, as the size of the droplets was kept unchanged after 1 month, as well as the uniformity parameter. Morphological investigation confirmed a homogenous droplet distribution for both samples. Silicones enhanced the viscosity, compactness and strength of the cream, providing a suitable stability profile both at room temperature and when heated at 40°C. The solid‐like viscoelastic behaviour was assessed in the presence of dynamic oscillatory stresses. The monitoring of TEWL over time demonstrated non‐occlusive properties of emulsions containing silicones, the values of which were comparable to the negative control. Silicone‐based emulsions gained higher scores from the volunteers in silkiness, freshness and softness features, while lower scores were obtained in greasiness compared to silicone‐free emulsions. No cases of irritation were recorded by the candidates. Conclusion: The presence of specific silicones inside a cosmetic product improved its technological characteristics. The rheological identity and the stability feature showed the real suitability of prepared emulsion as a cosmetic product. Moreover, this study demonstrated that silicone‐based emulsions are safe for the skin and did not cause skin occlusion. Improved skin sensations are registered by potential consumers when silicones are included in the formulation. [ABSTRACT FROM AUTHOR]

The paper presents the rheological behavior study of cosmetic emulsions as well as their oxidation stability. The influence of temperature and of the cooling rate was determined, as well as that of the active principles content on the rheological behavior, by setting the dependence between the shear stress τ and the shear rate. The analysis of this dependence demonstrates that these emulsions present non-Newtonian behavior. The oxidation stability was monitored for 210 days by determining the peroxide value and the presence of initial and final oxidation products (by monitoring K232 and K270 values, respectively). [ABSTRACT FROM AUTHOR]

Technological innovation in the cosmetic field must necessarily consider not only the safety and efficacy requirements but also the growing attention to environmental issues and the need for sensory pleasure during application to satisfy the consumers’ expectations. This work aimed to formulate an oil-in-water fluid emulsion stabilized by the combination of organic and inorganic powders, namely Zea mays starch and zinc oxide associated at different ratios in presence of a polysaccharidic rheological modifier. After verifying the physical stability of the prototypes with a mechanical stress test in a centrifuge, the rheological analyses were conducted in continuous and oscillatory flow conditions, and the immersion/de-immersion test, conducted using a texture analyzer, allowed identifying the system with the viscoelastic characteristics and the parameters of textures, such as firmness, consistency, and adhesiveness, more suitable for the formulation of skin-care products with low viscosity and high spreadability. Finally, we studied the compatibility of the powders with sunscreen filters and pigments, to optimize the systems and assess their potential use in finished products.

[Display omitted] • A population balance model was implemented to design cosmetic emulsions. • Relationships between operating conditions, formulation, and properties were found. • PBM parameters were related to product formulation and operating conditions. • Results suggest that the proposed correlations link DSD to cosmetic emulsion design. The present study describes the relationship between operating conditions, product formulation, and product properties at different time and spatial scales applying a multiscale approach to the design of cosmetic emulsions. The study couples the rheological and textural properties of cosmetic emulsions, product formulation, and operating conditions with the drop size distribution (DSD) through the implementation of a Population Balance Model (PBM). The results indicate that the adjustable parameters of the PBM can be related to product formulation and operating conditions, which allows for the incorporation of emulsified product DSD in model-based design strategies. Empirical relationships for the model adjustable parameters of the model were proposed, allowing the application of the PBM over the experimental thickener concentration and agitation rate ranges. These relationships indicate that PBM can be coupled to the integrated emulsified product and process design, enabling the optimization of the production process, and enhancing the final product's quality. [ABSTRACT FROM AUTHOR]

• A model-based multiscale design approach is considered for emulsion design. • The strategy focuses on raw materials and energy efficient use. • The proposed strategy aligns with Goal 12 of the UN's 2030 Agenda. • Consumer preference maximization may not necessarily correlate with higher profits. • Profit maximization properly balances consumer preference and economic performance. There is an increasing demand for sustainable and cost-effective chemical products, such as eco-friendly emulsified products, contributing to a resource-efficient economy and a reduction in our ecological footprint. This new paradigm challenges the chemical industry due to a lack of accurate predictive models and understanding of emulsified systems. This study presents an optimization strategy to design cosmetic emulsions through a multiscale approach, which represents an opportunity to boost and improve the design of these products. The study employs a model-based design approach considering operating conditions, product formulation, economic performance, consumer preference, and the emulsions properties at different scales. At the macroscopic scale, rheological and textural properties are considered and coupled with a Population Balance Model, which estimates the drop size distribution (i.e., microscopic scale). The optimal emulsion formulation is established for consumer preference and product profit maximization scenarios. According to the economic model, a higher level of consumer preference is expected to lead to increased product sales. However, the results also indicate that consumer preference maximization may not necessarily correlate with higher profits. Thus, the profit maximization scenario offers a better balance between consumer preference and economic performance. Also, experimental validation was performed for the product properties and operating conditions. [Display omitted] [ABSTRACT FROM AUTHOR]

The authors report the rheology and shear flow velocity profiles of pseudo-ternary "lamellar gel networks" commonly found in cosmetic emulsions such as creams, lotions, and hair conditioners, consisting of the cationic surfactant behentrimonium methosulfate, a fatty alcohol mixture of cetyl and stearyl alcohol, and water at surfactant/fatty alcohol mole fractions ranging from 0.1 to 0.6 and water mass fractions of 85%–97%. The high shear-thinning viscosity shows hysteresis in up- and down-ramps of the shear rate, with the gel "remembering" its highest shear for around 12 h before it heals and recovers its original viscosity. These materials exhibit rheological signatures characteristic of a soft glassy material (as described by the soft glassy rheology model) such as shear hysteresis, inhomogeneous velocity gradient, a solidlike creep response, power-law stress decay in step strain experiments, and high storage modulus relative to loss modulus over a wide range of frequencies, confirming its nearly elastic response for small deformations. Using particle image velocimetry (PIV) in steady shear experiments, a transition from a linear velocity profile to a pluglike profile was observed at shear rates above around 0.01 s−1. PIV also revealed macroscopic inhomogeneities including the development of fracture planes and shear bands, with rheology becoming gap-dependent and displaying some characteristics of solidlike friction. [ABSTRACT FROM AUTHOR]

Olive oil application in the cosmetic industry may be extended by its ozonation, bringing about new oil properties and increased stability. Olive oil treated with 0.04 mole O3 or 0.10 mole O3 per 100 g oil was subjected to chemical parameters evaluation and composition scrutinizing by gas chromatography–mass spectrometry (GC-MS) and headspace solid-phase microextraction (HS-SPME) GC-MS analysis. The biological activity of refined and ozonated oil included their antimicrobial properties by the agar diffusion method and cytotoxicity by the MTT assay towards two normal (LLC-PK1, HaCaT) and two cancerous (Caco-2, HeLa) cell lines. The oils served as the basis in cosmetic emulsions. The chosen organoleptic features, preservative efficacy in a challenge test, and persistency during six months of these formulations were assessed. However, the ozonation of the olive oil resulted in a decrease in unsaturated acids; several additional compounds were detected in the ozonated oil, which positively affect the physicochemical, sensory, and functional properties of cosmetic emulsions. Emulsions based on the ozonated olive oil retain their properties longer compared to emulsions based on the refined olive oil. Ozonated oil treated with 0.10 mole O3/100 g oil allowed increasing the shelf life of the non-preserved formulation up to six months. A weak inhibitory effect against Candida albicans and Aspergillus brasiliensis was also demonstrated for this emulsion in the challenge test. Moreover, an interesting aroma, slightly enhanced antimicrobial activity against Escherichia coli, Staphylococcus aureus, C. albicans, A. brasiliensis, and a lack of cytotoxicity at concentrations 625 µg mL−1 make the ozonated olive oil a promising raw material for the cosmetics and pharmaceutical industries.

In the present study, a chitosan (CS) derivative with the 2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SDAEM) zwitterionic monomer was prepared through chemical modification. The successful synthesis of CS-SDAEM was confirmed by Fourier-transform Infrared (FTIR) and Nuclear Magnetic Resonance (1H-NMR) spectroscopies. Its crystallinity was studied by X-ray Diffraction (XRD), while in vitro cytotoxicity and cell viability assays established its biocompatibility. Filtered fresh pomegranate juice (PJ) was loaded in nanoparticles of neat CS and its derivative via ionic gelation method. Dynamic Light Scattering (DLS) revealed nanoparticles sizes varying between 426 nm and 4.5 μm, indicating a size-dependence on the polymer concentration used during encapsulation. High-performance liquid chromatography coupled with photodiode array and electrospray ionization mass spectrometry detection (LC-PDA-ESI/MS) revealed that PJ active compounds were successfully and in sufficient amounts encapsulated in the nanoparticles interior, whereas XRD indicated a crystalline structure alteration after nanoencapsulation. The resulted PJ-loaded nanoparticles were further utilized for the preparation of innovative O/W cosmetic emulsions. All produced emulsions exhibited good pH and viscosity stability for up to 90 days, while the sun protection factor (SPF) was enhanced due to the presence of the PJ. Enhanced antioxidant and antimicrobial properties due to the phenolic compounds of PJ were also observed.

Phytic acid is a natural compound widely used as depigmenting agent in cosmetic emulsions. Few studies are available in the literature covering the stability and the antioxidating property of this substance, used alone or into emulsions. Therefore, the purpose of this work was to investigate the thermal behavior and antioxidant properties of phytic acid alone and into cosmetic emulsions. The thermal behavior of this substance was evaluated by thermogravimetry (TG)/derivative thermogravimetry (DTG) and differential scanning calorimetry (DSC) and the free-radical-scavenging activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH). TG/DTG and DSC curves allowed evaluation of the thermal behavior of phytic acid. These results showed that the substance presented four stages of mass loss. Thermal decomposition of the material initiated at 150 °C. Thermal behavior of the cosmetic emulsions detected that the addition of phytic acid decreased the thermal stability of the system. DPPH free-radical-scavenging activity showed that phytic acid incorporated into emulsion had no antioxidant capacity compared to BHT. In summary, we concluded that the thermoanalytical techniques (TG and DSC) were efficient and reliable in the characterization of phytic acid alone and incorporated into cosmetic emulsions.

Sensory properties are fundamental in determining the success of a cosmetic product. In this work, we assessed the influence of different oils and emulsifiers on the physicochemical and sensory properties of anti-ageing cosmetic O/W emulsions containing vitamin E acetate as active ingredient. No clear correlation between physicochemical properties and sensory characteristics was evidenced. Sensorial evaluation of these formulations pointed out that the emulsifier systems affected the perceived oiliness and absorbency during application of the product, thus influencing its acceptance. These results suggest the need for more detailed studies on the physicochemical factors involved in determining the consumers’ acceptance.

Rheological properties are crucial for cosmetic formulations, determining product's properties during production and application. O/W emulsions (pH 6.86-7.10) were prepared with decyl-oleate as internal phase. A-formulations contained K-stearate, while N-formulations contained polyglyceryl-stearate and -behenate as principal emulsifiers. The formulations were prepared by adding the water to the oil phase (NA and AA) or vice versa (NB and AB). Oscillatory measurements were performed on Haake RheoStress using double gap cylinder. In amplitude sweep at low stresses all samples behaved as viscoelastic solids. With increasing stress, phase angles increased to >80o. Crossover of storage and loss moduli for AA happened at nine times higher stress compared to the other formulations, forming lamellar crystalline gel network. Linear viscoelastic region showed that AA was much more stable. Frequency sweep showed NA and AB to be liquid-like. In NB and AA decrease in complex viscosity indicates better spreadability. Stability of phase angles and storage and loss moduli indicate more elastic behavior. New nonionic emulsifier was more independent of processing, unlike anionic emulsifier. However, AA formulation gives much better feel properties, needed in cosmetic formulations. [ABSTRACT FROM AUTHOR]

A set of 31 cosmetic emulsions, as the most frequent cosmetic dispersions, comprising lotions and creams (o/w, w/o), was analyzed by rheological procedures (RheoStress 300, Thermo Fischer Scientific) and by sensory profiling. The power law model was used for pseudoplastic body lotions and the Herschel-Bulkley model for viscoplastic creams to get basic rheological parameters (apparent viscosity, consistency parameter, yield stress value, plastic viscosity and flow behaviour index). The content of TiO2 in sun lotions probably caused better agreement with viscoplastic creams. Rheological analysis proved to be more suitable for the storage stability testing of the emulsion than sensory evaluation. Psychorheology was applied as a suitable complex method. Rheological parameters were compared to sensory texture attributes (removing from a package, ease of spreading, skin feel and thickness). Almost 60% of relationships among rheological and sensory parameters were statistically significant (P = 0.05). Considering relationships only between rheological and sensory characteristics (with each other), 46 % were statistically significant (P = 0.05). In the case of apparent viscosity and removing the lotion from a bottle the relationship was reliable enough (correlation coefficient 0.91) to estimate the sensory attribute by fast rheological measurement. The other statistically significant relationships (correlation coefficients 0.53-0.80) proved that the sensory texture acceptability of a cosmetic emulsion could be partly predicted by rheological analysis.

Abstract: The objectives of the study were to investigate the effect of various polymers on both the rheological and mechanical properties of cosmetic O/W emulsions on one hand, and to investigate the relationships between rheological and textural parameters of the emulsions on the other hand. For this purpose, eight hydrophilic polymers, either natural (e.g. xanthan gum), or natural modified (e.g. hydroxyethyl cellulose) or synthetic (e.g. carbomer), were incorporated in an O/W emulsion at a concentration of 1% w/w. In addition, a formulation without any polymer was also prepared to be used as a control. The rheological assessment was carried out by analyzing continuous shear flow, creep-recovery and dynamic oscillatory tests, while penetration and compression tests were performed using a texture analyzer under various experimental conditions. This work showed that rheology and texture analysis are useful and complementary tools to allow full understanding of the role of a particular ingredient in an emulsion formulation. It notably allowed establishing that distinct shear thinning behavior induce marked differences for the textural parameters. As an example, the xanthan-based emulsion was the system for which the textural parameters obtained during texture analysis were the less affected by increasing probe speed or container’s diameter, due to its extreme shear thinning behavior as evidenced by flow rheometry. [Copyright &y& Elsevier]

Abstract: This study deals with the impact of emollients on the spreading properties of cosmetic products using a combined sensory-instrumental approach. To that purpose, three esters and one silicone were selected and incorporated separately into an oil phase. Different cosmetic o/w emulsions were then prepared with these different oil phases. Both of them were analyzed by instrumental techniques and in vivo sensory analyses. A significant effect of the emollient used was established in emulsions and in oil phases as well. Concerning emulsions, results reveal a clear correlation between in vivo spreading evaluation and friction coefficient parameters measured by texture analyzer, despite a fairly low correlation coefficient (Pearson coefficient=−0.78). Concerning oil phases, characterization of spreading was done by monitoring the contact angle relaxation of a drop of solution after deposition on a flat PMMA surface whereas sensory procedure was based on spontaneous spreading of oil phases onto the skin. Finally, good correlations between in vivo sensory analysis and instrumental measurements of both oils and emulsions were found, thus promising the possible development of predictive tools to evaluate spreadability. [Copyright &y& Elsevier]

Synopsis The effects of different emulsifiers on the in vitro permeation through human skin of two sunscreen agents [octylmethoxycinnamate (OMC) and butylmethoxydibenzoylmethane (BMBM)] were investigated from O/W emulsions. The test formulations were prepared using the same oil and aqueous phase ingredients and the following emulsifier and coemulsifier systems: Emulgade SE® (ceteareth-12 and ceteareth-20 and cetearyl alcohol and cetyl palmitate) and glycerylmonostearate (emulsion 1); Brij 72® (steareth-2), Brij 721® (steareth-21) and cetearyl alcohol (emulsion 2); Phytocream® (potassium palmitoyl-hydrolysed wheat protein and glyceryl stearate and cetearyl alcohol) and glycerylmonostearate (emulsion 3); Montanov 68® (cetearyl glucoside and cetearyl alcohol) (emulsion 4); Xalifin-15® (C15–20 acid PEG-8 ester) and cetearyl alcohol (emulsion 5)... [ABSTRACT FROM AUTHOR]

This paper presents basic research results for production of W/O, O/W and W/O/W cosmetic emulsions under ultrasonic irradiation. A technology for the continuous and batch treatment of fluid mixtures with ultrasound was characterized using cosmetic emulsions as model systems. If cavitation is the dominant mechanism of droplet disruption, these results have to be taken into account for an optimal design of the emulsification apparatus geometry. The theoretical model supports experimental work. The experimental findings prove that final drop size essentially depends on specific power density. Drop size decreases with increasing residence time in the ultrasonic field until a system specific, minimum drop size is obtained. Ultrasonic irradiation leads to turbulent flow conditions on a macroscopic and a microscopic scale. The model based on the theory of turbulent drop bread-up predicts drop size and can be used to design equipment for ultrasonic emulsification. Emulsion used were stabilized using a combination of hydrophilic and hydrophobic surfactants. The ratio of this surfactants is important in achieving stable cosmetic emulsions. It was shown that emulsifier concentration plays great role in controlling the emulsification processes as well as the structured features of the droplets. The rheological behavior and morphological evolution during the ultrasonic emulsification were characterized systematically. The rheological properties were used to asses emulsion stability. [ABSTRACT FROM AUTHOR]

Cosmetic oil-in-water emulsions with a stearyl phosphate emulsifier are examined by means of static and dynamic 31P nuclear magnetic resonance (NMR) techniques to characterize the molecular properties of the emulsifier in situ. The interfacially bound emulsifier can be deteced by high-resolution NMR spectroscopy, whereas the excess emulsifier exists as a solid lipid phase not detectable by this technique. The emulsions and the emulsifier raw material, consisting of monostearyl phosphate as well as distearly phosphate, are examined by solid state cross polarization magic angle spinning NMR spectroscopy to prove the existence of solid emulsifier phases in the emulsions. By applying dynamic 31P NMR methods to the interfacially bound emulsifier, information about the molecular dynamics at the interface is obtained. The results of the T 1 and T 2 relaxation time measurements indicate a restricted motion of the molecules that is dependent on the oil droplet size in the emulsions. This is verified by 31P NMR pulsed gradient spin echo self-diffusion measurements on emulsions with different droplet sizes. Only about 5 wt% of the total emulsifier used is bound at the interface; the excess forms solid lipid phases. The coverage of the interface seems to be independent of the emulsifier concentration. Only the monoester of the emulsifier raw material shows interfacial activity. Its mobility indicates the two-dimensional environment of the molecules on the surface of the oil droplets. [ABSTRACT FROM AUTHOR]

Olive oil application in the cosmetic industry may be extended by its ozonation, bringing about new oil properties and increased stability. Olive oil treated with 0.04 mole O3 or 0.10 mole O3 per 100 g oil was subjected to chemical parameters evaluation and composition scrutinizing by gas chromatography–mass spectrometry (GC-MS) and headspace solid-phase microextraction (HS-SPME) GC-MS analysis. The biological activity of refined and ozonated oil included their antimicrobial properties by the agar diffusion method and cytotoxicity by the MTT assay towards two normal (LLC-PK1, HaCaT) and two cancerous (Caco-2, HeLa) cell lines. The oils served as the basis in cosmetic emulsions. The chosen organoleptic features, preservative efficacy in a challenge test, and persistency during six months of these formulations were assessed. However, the ozonation of the olive oil resulted in a decrease in unsaturated acids; several additional compounds were detected in the ozonated oil, which positively affect the physicochemical, sensory, and functional properties of cosmetic emulsions. Emulsions based on the ozonated olive oil retain their properties longer compared to emulsions based on the refined olive oil. Ozonated oil treated with 0.10 mole O3/100 g oil allowed increasing the shelf life of the non-preserved formulation up to six months. A weak inhibitory effect against Candida albicans and Aspergillus brasiliensis was also demonstrated for this emulsion in the challenge test. Moreover, an interesting aroma, slightly enhanced antimicrobial activity against Escherichia coli, Staphylococcus aureus, C. albicans, A. brasiliensis, and a lack of cytotoxicity at concentrations 625 µg mL−1 make the ozonated olive oil a promising raw material for the cosmetics and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

Lecithin in cosmetic emulsions produces a unique “skin feel,” which can be related to its rheological properties. In this study, water-in-oil (w/o) and oil-in-water (o/w) emulsions were made from a cosmetic-grade caprylic/capric triglyceride with deoiled lecithin and hydroxylated lecithin. Synthetic surfactants commonly used in commercial cosmetic products were used as controls. Optical light microscope investigation showed significant differences in the structures of the w/o and o/w emulsions made with the lecithins. Freeze/thaw tests were conducted to evaluate emulsion stability. The o/w emulsion (oil/water = 20:80) was stable with 3% hydroxylated lecithin at room temperature. However, 4% hydroxylated lecithin was needed for stabilizing the emulsion with an oil-to-water ratio of 20:80 or 30:70 through the freeze/thaw treatments. With 4% deoiled lecithin, the w/o emulsion showed a water-holding capacity up to 80%, which was also stable through two freeze/thaw cycles. All emulsions in this study exhibited pseudoplastic flow, in which a minimum shearing stress, a yield value, was required before flow became linear. In general, the emulsion viscosity increased as lecithin content increased. Changing the oil-to-water ratio also affected the emulsion viscosity. The deoiled lecithin-based w/o emulsions had higher yield values than hydroxylated lecithin-based o/w emulsions. Therefore, more force was needed to spread the w/o emulsions. In addition, because w/o emulsions had more viscous continuous phases and a greater volume of internal phases, the w/o emulsions were more viscous than the o/w emulsions. [ABSTRACT FROM AUTHOR]

In the present study, a chitosan (CS) derivative with the 2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SDAEM) zwitterionic monomer was prepared through chemical modification. The successful synthesis of CS-SDAEM was confirmed by Fourier-transform Infrared (FTIR) and Nuclear Magnetic Resonance (1H-NMR) spectroscopies. Its crystallinity was studied by X-ray Diffraction (XRD), while in vitro cytotoxicity and cell viability assays established its biocompatibility. Filtered fresh pomegranate juice (PJ) was loaded in nanoparticles of neat CS and its derivative via ionic gelation method. Dynamic Light Scattering (DLS) revealed nanoparticles sizes varying between 426 nm and 4.5 μm, indicating a size-dependence on the polymer concentration used during encapsulation. High-performance liquid chromatography coupled with photodiode array and electrospray ionization mass spectrometry detection (LC-PDA-ESI/MS) revealed that PJ active compounds were successfully and in sufficient amounts encapsulated in the nanoparticles interior, whereas XRD indicated a crystalline structure alteration after nanoencapsulation. The resulted PJ-loaded nanoparticles were further utilized for the preparation of innovative O/W cosmetic emulsions. All produced emulsions exhibited good pH and viscosity stability for up to 90 days, while the sun protection factor (SPF) was enhanced due to the presence of the PJ. Enhanced antioxidant and antimicrobial properties due to the phenolic compounds of PJ were also observed. [ABSTRACT FROM AUTHOR]