International Journal of Cosmetic Science最新文献

Objective: Formulators today know that when traditional surfactants and polymers are replaced new problems occur. What was before a 'thickening problem' becomes a 'miscibility problem': the ingredients do not play well with each other anymore. However, the scientific rules are not different for these systems, which can also be understood and controlled. This study was therefore made, focusing on one of the important challenges, namely the phase separation and miscibility problem of polymers and surfactants in aqueous solution in ratios and concentrations of interest as shampoo chassis. There are three main reasons for these problems: (1) Impurities and variability from raw materials, (2) by-products or excess components and (3) high levels of background salt remaining from processing. In this work, the third factor has been investigated to learn when salts should be reduced or counteracted depending on the polymer type used for enabling thickening in the new formula spaces. Thus, the study is fundamental in nature but aims to facilitate communication with suppliers of both surfactants and polymers as well as with colleague formulators. It aims at an increased holistic approach where all ingredients are acknowledged constituents of the system, and even minor additions of simple salts are noted as relevant variables to control to maximize product performance.

Methods: Visual characterization of phase behaviour and viscosity assessment has been performed where three polymers have been combined with two different sulphate-free surfactants. Emphasis has been put on the effect of background salts.

Results: The levels of background salts affect both viscosity and compatibility of the systems investigated, however, to different extents depending on the nature of the materials. It is therefore important to control the levels of salt (often included in the raw materials), and how this affects the nature of the polymer-surfactant interactions, to reach the desired formulation attributes.

Conclusion: While prior knowledge based on classical aqueous polymer-surfactant systems was seen to be valid also for newer sulphate-free systems (as long as the salt concentration could be controlled), fully compatible mixtures where viscosity and surfactant concentrations truly meet the levels desired for the end formulation proved difficult to find.

Objective: Tactile perception of the skin is a key factor for consumers when evaluating skincare products, yet conventional sensory assessments are subjective, costly and often lack clear physical interpretations. This study aims to bridge this gap by developing a tactile sensor that quantifies physical parameters relevant to skin feel and combines these measurements with sensory evaluation.

Methods: A tactile sensor with a stainless-steel probe replicating a human fingerprint was developed to measure physical parameters-specifically, vibration and friction-during controlled rubbing on the cheek. Simultaneously, blinded sensory evaluations were performed by assessors rating six attributes: smooth-rough, moisturized-dry, soft-hard (surface), soft-hard (base), elastic-not elastic and oily-not oily. Multiple regression analyses were conducted using vibration features and friction coefficients as independent variables and sensory evaluation scores as dependent variables.

Results: Regression analysis revealed that perceived smoothness (smooth-rough) was predicted by amplitudes of high-frequency vibration (R² = 0.708; adjusted R² = 0.676). Moistness (moisturized-dry) was best predicted by a combination of high-frequency vibration amplitude and friction coefficients (R² = 0.584; adjusted R² = 0.538). No significant regression models were obtained for the other sensory attributes.

Conclusion: These findings highlight the potential of objective, instrument-based tactile measurements to elucidate the physical basis of sensory evaluation terms in skincare. This approach may enhance the training of sensory evaluation panels and improve the consistency and reliability of product assessment, ultimately supporting more effective product development.

Background: Hair loss is among the top concerns for Chinese men. Current clinical diagnosis is based on the Hamilton-Norwood classification as a macroscopic tool to recognise different severity levels and the phototrichogram (PTG) to show hair regrowth status within a shaved zone. However, it has limited dynamics and sensitivity to assess consumers with mild hair loss problems or at the early onset of hair loss. Therefore, we aim to develop a zoom-in hair fall atlas based on trichoscopy to better evaluate consumer hair fall problems.

Methods: Four hundred healthy Chinese men with different hair fall severity of Hamilton-Norwood classification are recruited, pictures collected and scalp measurements conducted in a total of 3 days. Later, 5 dermatologists will select representative images to build the atlas and score the rest of the images accordingly.

Results: A hair fall atlas based on scalp micro images was established, with 7 grades to represent the wide variety of consumer hair-fall severities. Each dermatologist scored images that covered all the grades. Good consistency was achieved between the 5 dermatologists (Pearson correlation coefficient >0.8). Our results also showed great repeatability between two scores of the same dermatologist (intraclass correlation coefficient >0.9). In addition, a strong correlation was shown between clinical scores and hair fall attributes of scalp visibility % and hair diameter based on image analysis (|p| > 0.8).

Conclusion: The FISHS hair fall atlas is well-established, validated and ready to be incorporated as a new methodology to guide anti-hair fall evaluation and aid in product development.

Ficus deltoidei, a medicinal plant traditionally used in Southeast Asia, is rich in bioactive flavonoids such as vitexin and isovitexin. Despite its long-standing use in traditional medicine, scientific validation of its dermatological benefits remains limited. This study aimed to evaluate the in vitro safety of F. deltoidea leaf extract and the efficacy of a topical herbal cream containing F. deltoidea leaf extract in promoting skin barrier recovery, including transepidermal water loss (TEWL), hydration, melanin, erythema and elasticity. The safety of F. deltoidea leaf extract was evaluated using three in vitro assays: a reconstructed human epidermis (RHE) model for irritation assessment, a direct peptide reactivity assay (DPRA) for skin sensitization potential and a direct cell contact cytotoxicity test on L-929 mouse fibroblast cells. The extract was categorized as a non-irritant in the RHE test, with tissue viability remaining above 50%. All acceptance criteria were met, showing an average peptide depletion of 10.21% in the DPRA, classifying it as low reactive, and it was found to be non-cytotoxic at a 0.1% concentration. An in vivo tape-stripping model was employed in 20 human volunteers to simulate superficial skin barrier disruption. The test sites were treated with F. deltoidea cream, placebo cream, or untreated skin (control). Treatment with F. deltoidea cream significantly accelerated skin barrier repair, as evidenced by a marked reduction in TEWL and improved hydration compared with the placebo and control groups. The formulation also reduced erythema and melanin levels, indicating anti-inflammatory and anti-melanogenic effects, and enhanced skin elasticity, suggesting anti-aging potential. Pearson's correlation analysis revealed strong interdependence among the parameters, with TEWL being negatively correlated with hydration (r = -0.96) and elasticity (r = -0.84), whereas hydration was positively correlated with elasticity (r = 0.95). The therapeutic effects of F. deltoidea cream are attributed to its flavonoid content and antioxidant properties. This study provides scientific support for the traditional use of F. deltoidea in skin-related treatments. Further investigations into the mechanism of ceramide synthesis in the stratum corneum are warranted.

Objective: Fragrances cause brainwave modulations, consequently affecting skin health; however, the scientific explorations of these fragrance effects are lacking. This study aimed to investigate whether neuromodulatory fragrances, identified through electroencephalography (EEG), enhance sleep quality and consequently improve physiological skin parameters. Furthermore, we explored the potential of fragrance-induced neural modulation as a novel strategy for cosmetic formulations.

Methods: Thirty healthy adults were exposed to four fragrances, and their EEG responses were analysed to assess emotional valence and arousal. The powdery scent (PD53), which produced the strongest alpha wave activity, and the rose scent (RS52), which induced the weakest response, were formulated into creams. An unscented cream served as the control. Participants applied the test creams every night for 4 weeks, and skin parameters were measured before and after the treatment.

Results: Participants in the PD53 group exhibited significantly higher sleep quality scores than those in the unscented control group, along with an increased skin elasticity and decreased transepidermal water loss, roughness, desquamation index, yellowness, sebum production and pore area (p < 0.05). No significant intergroup differences were observed in terms of hydration, wrinkles, brightness or hyperpigmentation.

Conclusion: Alpha wave activation induced by neuromodulatory fragrances positively influences specific skin properties by improving sleep quality. This approach may represent a novel functional strategy for developing cosmetic formulations aimed at enhancing skin health.

Objective: Measuring the influence of cosmetic ingredients on the microbiota-skin-brain axis is a difficult challenge. Here, we try to build a connection between the commensal S. epidermidis, its post-biome, influence on neurotransmitter release in skin and emotional response to the use of an extract from Cichorium intybus.

Methods: Measurement of skin evenness with physical measurements, objective and subjective perception. Measurement of emotional arousal with galvanic skin response, advanced facial and eye tracking system, and electro encephalography. Of note, not only were the subjects investigated but also the person caressing the treated subjects. The influence of the skin's microbiota was determined using a 3D epidermal skin model, a keratinocyte/neuron coculture, and bacterial cultures.

Results: C. intybus extract leads to smooth skin and positive excitement of subjects using the cosmetic formulation. Additionally, it evoked positive emotions in a person caressing the treated skin. Treatment of Staphylococcus epidermidis with the extract induced the secretion of bioactive post-biotics that promote neurotransmitter release, suggesting a potential stimulatory effect on neuronal activity. Given that this bacterial stimulation does not involve proliferation, we define this prebiotic state as 'activated rest.'

Conclusion: C. intybus extract is a candidate to elucidate the complex relationship between skin microbiota, skin perception, and emotional response of subjects using cosmetic products, even influencing social interaction on others.

Sensory analysis is a cornerstone of cosmetic development, yet remains underrepresented in peer-reviewed literature due to its frequent confinement to internal or industrial use, unlike food science, where shared methodologies foster wider academic development. This review explores the multiple dimensions of haptics as tactile sensory analysis in cosmetics, underscoring its central role in product development. The skin, as the primary organ of touch, is examined in detail, along with the eye, which plays a secondary role in the perception of cosmetic products. Particular emphasis is placed on the biological mechanisms underpinning sensory evaluation, especially the role of mechanoreceptors and photoreceptors in stimulus detection, neural transmission and sensory response generation. These responses, evaluated by expert assessors, form the basis of standardized sensory protocols. The review covers key methodologies, from discriminatory and hedonic tests to descriptive sensory analysis, each with its strengths and limitations. Conventional sensory profiling remains robust but time- and resource-intensive, prompting interest in faster alternatives such as free-choice profiling or flash profiling. While more flexible, these methods pose challenges in terms of variability and data interpretation. Instrumental techniques, such as texture analysis, rheology and biometrological approaches, are increasingly integrated as proxies to provide quantitative data that correlate with standardized sensory evaluations. These tools enhance analytical accuracy and enable product testing in contexts where human trials may not be feasible. Finally, the review highlights emerging innovations: virtual and augmented reality, artificial intelligence and electronic sensing devices are reshaping the landscape of sensory evaluation. These technologies support predictive modelling and objective assessment, though their implementation raises new challenges, including the artificial modulation of perception and environmental control. This pedagogical review provides a comprehensive overview of tactile sensory analysis in cosmetics, bridging traditional methods with cutting-edge innovations and offering guidance for future research and application.

Objective: Rhizospheric microorganisms play a crucial role in plant vitality by contributing to nutrient supply and overall plant health. This research focused on a specific yeast isolated from the rhizosphere of Rosa hybrid delflobla and aimed to investigate if a resulting natural active ingredient can have cosmetic benefits, particularly concerning NAD+, a cofactor known to play a vital role in skin longevity.

Methods: The yeast Aureobasidium pullulans, sampled in the rhizosphere of Rosa hybrid delflobla, was processed to generate a natural active ingredient (INCI: Aureobasidium pullulans ferment). The efficacy of this active ingredient was investigated on NAD+ (nicotinamide adenine dinucleotide) synthesis, a crucial molecule playing a fundamental role in energy metabolism and a multitude of key cellular processes, as well as on cutaneous barrier function and related skin benefits.

Results: The results of this study demonstrate that the Aureobasidium pullulans ferment increases the NAD+/NADH ratio. Moreover, the expression and synthesis of epidermal differentiation and cohesion markers are stimulated with this natural active ingredient, resulting in an improved barrier function. Clinical results demonstrate that the Aureobasidium pullulans ferment smooths skin microrelief and enhances complexion radiance.

Conclusion: Altogether, these results reveal that the active ingredient obtained from the Rosa hybrid delflobla rhizosphere (INCI: Aureobasidium pullulans ferment) has highly interesting potential to improve skin resilience and longevity.

Aims: The physicochemical stability of cosmetic emulsions is crucial for successful commercialization and consumer satisfaction. This study presents an innovative protocol that combines rheology, turbidimetry and granulometry to predict emulsion stability more efficiently.

Materials and methods: Industrial emulsions, including some commercial products, were selected to compare stable and unstable samples with minimal formulation differences. Granulometry, turbidimetry and rheology assessments were used to evaluate physical and structural properties. The collected data were subjected to advanced statistical analysis using experimental design methods.

Results: Granulometry, turbidimetry and rheology each effectively distinguished stable from unstable emulsions. Stable emulsions maintained a constant median particle size, while unstable samples exhibited significant increases. Viscosity changes were observed only in unstable emulsions. Turbidimetry showed a Turbiscan Stability Index (TSI) >3 for unstable emulsions and <3 for stable ones. Notably, this combined protocol identified instability as early as 8 days-much faster than standard ISO methods, which require up to 30 days.

Conclusions: Integrating granulometry, turbidimetry and rheology with advanced data analysis enables a rapid, reliable and sensitive prediction of cosmetic emulsion stability. This approach overcomes the limitations of traditional testing by allowing earlier detection of instability, improving formulation development, quality control and time-to-market. Future work will assess the protocol's applicability to a wider range of emulsion types.

Objective: This study investigates the impact of hydrophobic Natural Eutectic Solvents (NES) on the physicochemical and sensory characteristics of cosmetic creams. The aim is to assess their potential as innovative, sustainable ingredients introduced directly into the oily phase of an oil-in-water emulsion prior to emulsification.

Methods: Four NES formulations, composed of natural components such as caprylic acid, lauric acid, menthol and 1,3-propanediol were incorporated at 10% wt. into a COSMOS-compliant cream chassis. The resulting creams were evaluated for physical stability using static multiple light scattering (Turbiscan®), rheological behaviour via shear and oscillatory tests, and sensory attributes through a trained panel.

Results: Among the four NES-containing creams, three formulations demonstrated satisfactory physical stability over 30 days under accelerated ageing conditions. Menthol-based NES induced phase separation, correlating with increased droplet size and higher Turbiscan Stability Index values. All creams exhibited shear-thinning behaviour, with viscosity profiles and yield stress varying depending on NES composition. Sensory analysis revealed that NES significantly influenced key attributes such as odour intensity, spreading, pick-up and firmness.

Conclusion: Hydrophobic NES can be successfully integrated into the internal phase of cosmetic creams, influencing both their structural and sensory properties. These findings highlight their potential as multifunctional and eco-friendly ingredients in cosmetic formulation, supporting the development of more sustainable, more performant skincare products.