Red Raspberry Seed Oil Low Energy Nanoemulsions: Influence of Surfactants, Antioxidants, and Temperature on Oxidative Stability.

The aim of this study was to assess and improve the oxidative stability of red raspberry seed oil−RO, a potential topical ingredient derived from food industry by-products, on its own and when incorporated in low energy nanoemulsion (NE). The RO's oxidative stability was assessed at 5, 25, and 40 °C during one month of storage and expressed in: peroxide value, p-anisidine, and thiobarbituric reactive substances­TBARS value, while for NEs, lipid hydroperoxides and TBARS values were monitored. Both synthetic (butylated hydroxytoluene­BHT and ethylenediaminetetraacetic acid­EDTA), and natural (oregano essential oil­ORE and oak fruit extract­OAK) antioxidants were used. Pure RO and RO with BHT or ORE were stable at 5 °C and 25 °C, but at 40 °C BHT showed only moderate protection, while ORE was prooxidant. NEs prepared with new biodegradable polyglycerol esters-based surfactants, with droplet sizes of < 50 nm and narrow size distribution, showed improved physicochemical stability at room temperature, and especially at 40 °C, compared to NEs with polysorbate 80, which required the addition of antioxidants to preserve their stability. Natural antioxidants ORE and OAK were compatible with all NEs; therefore, their use is proposed as an effective alternative to synthetic antioxidants.

Artificial Intelligence in hair research: A proof-of-concept study on evaluating hair assembly features.

OBJECTIVE: The first objective of this study was to apply computer vision and machine learning techniques to quantify the effects of haircare treatments on hair assembly and to identify correctly whether unknown tresses were treated or not. The second objective was to explore and compare the performance of human assessment with that obtained from artificial intelligence (AI) algorithms. METHODS: Machine learning was applied to a data set of hair tress images (virgin and bleached), both untreated and treated with a shampoo and conditioner set, aimed at increasing hair volume whilst improving alignment and reducing the flyway of the hair. The automatic quantification of the following hair image features was conducted: local and global hair volumes and hair alignment. These features were assessed at three time points: t0 (no treatment), t1 (two treatments) and t2 (three treatments). Classifier tests were applied to test the accuracy of the machine learning. A sensory test (paired comparison of t0 vs t2 ) and an online front image-based survey (paired comparison of t0 vs t1 , t1 vs t2 , t0 vs t2 ) were conducted to compare human assessment with that of the algorithms. RESULTS: The automatic image analysis identified changes to hair volume and alignment which enabled the successful application of the classification tests, especially when the hair images were grouped into untreated and treated groups. The human assessment of hair presented in pairs confirmed the automatic image analysis. The image assessment for both virgin hair and bleached only partially agreed with the analysis of the subset of images used in the online survey. One hypothesis is that treatments changed somewhat the shape of the hair tress, with the effect being more pronounced in bleached hair. This made human assessment of flat images more challenging than when viewed directly in 3D. Overall, the bleached hair exhibited effects of higher magnitude than the virgin hair. CONCLUSIONS: This study illustrated the capacity of artificial intelligence for hair image detection and classification, and for image analysis of hair assembly features following treatments. The human assessment partially confirmed the image analysis and highlighted the challenges imposed by the presentation mode.

OBJECTIF: Le premier objectif de cette étude était d'appliquer des techniques de vision par ordinateur et d'apprentissage automatique pour quantifier les effets des traitements capillaires sur l'organisation des cheveux et pour identifier précisément si des cheveux d'origine inconnue ont été traités ou non. Le deuxième objectif était d'explorer et de comparer les performances obtenues par évaluation humaine avec celles obtenues à partir d'algorithmes d'intelligence artificielle (IA). MÉTHODES: L'apprentissage automatique a été appliqué à un ensemble de données d'images de cheveux (vierges et décolorés), à la fois non traités et traités avec une association de shampooing et après shampooing visant à augmenter le volume des cheveux tout en améliorant l'alignement des fibres capillaires et en réduisant les frisottis. La quantification automatique des caractéristiques suivantes de l'image capillaire a été réalisée : volumes capillaires locaux et globaux et alignement des cheveux. Ces caractéristiques ont été évaluées à trois moments : t0 (pas de traitement), t1 (deux traitements), t2 (trois traitements). Des tests de classification ont été appliqués pour tester la précision de l'apprentissage automatique. Un test sensoriel (comparaison par paire de t0 vs t2) et une enquête en ligne basée sur l'image frontale (comparaison par paire de t0 vs t1, t1 vs t2, t0 vs t2) ont été menés pour comparer l'évaluation humaine avec celle des algorithmes. RÉSULTATS: L'analyse automatique des images a identifié des changements dans le volume et l'alignement des cheveux qui ont permis la validation des tests de classification, en particulier lorsque les images de cheveux ont été rassemblés en groupes non traités et traités. L'évaluation humaine des cheveux présentés par paires a confirmé l'analyse automatique des images. L'évaluation des images pour les cheveux vierges et décolorés n'était que partiellement en accord avec l'analyse du sous-ensemble d'images utilisées dans l'enquête en ligne. Une hypothèse est que les traitements ont quelque peu changé la forme de la chevelure, l'effet étant plus prononcé avec les cheveux décolorés. Cela a rendu l'évaluation humaine des images plates plus difficile que lorsqu'elles sont visualisées directement en 3D. Dans l'ensemble, les cheveux décolorés ont présenté des effets de plus grande ampleur que les cheveux vierges. CONCLUSION: Cette étude a illustré la capacité de l'intelligence artificielle pour la détection et la classification d'images capillaires, et pour l'analyse d'images des caractéristiques d'organisation des cheveux après traitements. Le bilan humain a partiellement confirmé l'analyse d'image et mis en évidence les enjeux posés par le mode de présentation.

Polyglycerol Ester-Based Low Energy Nanoemulsions with Red Raspberry Seed Oil and Fruit Extracts: Formulation Development toward Effective In Vitro/In Vivo Bioperformance.

This study focuses on the development of biocompatible oil-in-water (O/W) nanoemulsions based on polyglycerol esters, as promising carriers for natural actives: red raspberry seed oil-RO and hydro-glycolic fruit extracts from red raspberry-RE and French oak-FE. Nanoemulsions were obtained via phase inversion composition (PIC) method at room temperature by dilution of microemulsion phase, confirmed by visual appearance, percentage of transmittance, microscopic, rheological and Differential Scanning Calorimetry (DSC) investigations. The results have shown that the basic RO-loaded formulation could be further enriched with hydro-glycolic fruit extracts from red raspberry or French oak, while keeping a semi-transparent appearance due to the fine droplet size (Z-ave: 50 to 70 nm, PDI value ≤ 0.1). The highest antioxidant activity (~92% inhibition of the DPPH radical) was achieved in the formulation containing both lipophilic (RO) and hydrophilic antioxidants (FE), due to their synergistic effect. The nanoemulsion carrier significantly increased the selective cytotoxic effect of RO towards malignant melanoma (Fem-X) cells, compared to normal human keratinocytes (HaCaT). In vivo study on human volunteers showed satisfactory safety profiles and significant improvement in skin hydration during 2 h after application for all nanoemulsions. Therefore, polyglycerol ester-based nanoemulsions can be promoted as effective carriers for red raspberry seed oil and/or hydro-glycolic fruit extracts in topical formulations intended for skin protection and hydration.

Figaro-tresses: A dataset for evaluating hair assembly features before and after cosmetic treatment.

The published database is composed of 1,080 images taken from 120 hair tresses made of medium blond, fine Caucasian hair with the aim to facilitate quantitative and qualitative studies about shampoo and conditioner efficacies. Two types of hair tresses were used: Caucasian hair which had not been subjected to oxidation with bleaching agents - virgin (60 tresses); and Caucasian hair, previously subjected to light oxidative bleaching - lightly bleached (remaining 60 tresses). Since cosmetic products such as shampoos and conditioners are often designed to subtly augment hair assembly features via the carefully balanced cumulative effects of deposited actives, each tress was subjected to consecutive washing+conditioning+drying cycles referred to as cosmetic treatment. The shampoo and conditioner used for this project were specifically selected for their suitability for fine hair. Each tress was photographed at three different time-points: before the cosmetic treatment; after two cosmetic treatments, and after an additional third cosmetic treatment. At each time-point, each tress was photographed from three different angles (-45, 0, and +45°), resulting in a total number of nine images for each tress. For each image in the database, we also provide a corresponding hair segmentation mask, which identifies the hair location area in the original image.

Low-energy nanoemulsions as carriers for red raspberry seed oil: Formulation approach based on Raman spectroscopy and textural analysis, physicochemical properties, stability and in vitro antioxidant/ biological activity.

Considering a growing demand for medicinal/cosmetic products with natural actives, this study focuses on the low-energy nanoemulsions (LE-NEs) prepared via the Phase inversion composition (PIC) method at room temperature as potential carriers for natural oil. Four different red raspberry seed oils (ROs) were tested, as follows: cold-pressed vs. CO2-extracted, organic vs. non-organic, refined vs. unrefined. The oil phase was optimized with Tocopheryl acetate and Isostearyl isostearate, while water phase was adjusted with either glycerol or an antioxidant hydro-glycolic extract. This study has used a combined approach to formulation development, employing both conventional methods (pseudo-ternary phase diagram - PTPD, electrical conductivity, particle size measurements, microscopical analysis, and rheological measurements) and the methods novel to this area, such as textural analysis and Raman spectroscopy. Raman spectroscopy has detected fine differences in chemical composition among ROs, and it detected the interactions within nanoemulsions. It was shown that the cold-pressed, unrefined, organic grade oil (RO2) with 6.62% saturated fatty acids and 92.25% unsaturated fatty acids, was optimal for the LE-NEs. Textural analysis confirmed the existence of cubic gel-like phase as a crucial step in the formation of stable RO2-loaded LE-NEs, with droplets in the narrow nano-range (125 to 135 nm; PDI ≤ 0.1). The DPPH test in methanol and ABTS in aqueous medium have revealed a synergistic free radical scavenging effect between lipophilic and hydrophilic antioxidants in LE-NEs. The nanoemulsion carrier has improved the biological effect of raw materials on HeLa cervical adenocarcinoma cells, while exhibiting good safety profile, as confirmed on MRC-5 normal human lung fibroblasts. Overall, this study has shown that low-energy nanoemulsions present very promising carriers for topical delivery of natural bioactives. Raman spectroscopy and textural analysis have proven to be a useful addition to the arsenal of methods used in the formulation and characterization of nanoemulsion systems.

An alkyl polyglucoside-mixed emulsifier as stabilizer of emulsion systems: the influence of colloidal structure on emulsions skin hydration potential.

To be considered as a suitable vehicle for drugs/cosmetic actives, an emulsion system should have a number of desirable properties mainly dependent on surfactant used for its stabilization. In the current study, C(12-14) alkyl polyglucoside (APG)-mixed emulsifier of natural origin has been investigated in a series of binary (emulsifier concentration 10-25% (w/w)) and ternary systems with fixed emulsifier content (15% (w/w)) with or without glycerol. To elucidate the systems' colloidal structure the following physicochemical techniques were employed: polarization and transmission electron microscopy, X-ray diffraction (WAXD and SAXD), thermal analysis (DSC and TGA), complex rheological, pH, and conductivity measurements. Additionally, the emulsion vehicles' skin hydration potential was tested in vivo, on human skin under occlusion. In a series of binary systems with fixed emulsifier/water ratios ranging from 10/90 to 25/75 the predominance of a lamellar mesophase was found, changing its character from a liquid crystalline to a gel crystalline type. The same was observed in gel emulsions containing equal amounts of emulsifier and oil (15% (w/w)), but varying in glycerol content (0-25%). Different emulsion samples exhibited different water distribution modes in the structure, reflecting their rheological behavior and also their skin hydration capacity.

The role of vehicle-nanoparticle interactions in topical drug delivery.

Loading 'difficult to deliver' therapeutic agents into lipid nanoparticles (LN) is an attractive means to administer them to the skin. However, employing colloidal carriers to administer therapeutic agents from semi-solid preparations adds an extra dimension to the already complex process of topical drug delivery. The aim of this work was to understand how the mobility of nanoparticles influenced the delivery of a model drug when the carriers were suspended in a hyaluronic acid (HA) vehicle. Tocopheryl acetate (TA) was loaded into lipid nanoparticles (TA(LN)) that were <100 nm in size and physically stable for more than 28 days. The TA(LN) interacted with the HA polymeric chains to increase formulation macroviscosity. Nanoparticle tracking analysis confirmed that the gel hindered the TA(LN) mobility. However, deliberate manipulation of the particle mobility in the gel by varying the concentration of HA had little effect on TA delivery. Only ca. 10 µg/cm(2) of administered TA was delivered into porcine skin regardless of the vehicle characteristics and this suggested that drug release from the LN was the rate limiting step in the delivery process and not the nanoparticle-vehicle-skin interactions.

Tocopheryl acetate disposition in porcine and human skin when administered using lipid nanocarriers.

OBJECTIVES: Assessing the delivery of a drug into the skin when it has been formulated within a nanocarrier is a complex process that does not conform to the conventions of traditional semi-solid formulations. The aim of this study was to gain a fundamental understanding of drug disposition in both human and porcine skin when applied using a lipidic nanocarrier. METHODS: A model system was generated by loading tocopheryl acetate into a well-characterised solid lipid nanoparticle and formulating this system as a traditional aqueous hyaluronic acid gel. Franz diffusion cells fitted with a silicone or nylon membrane were used to assess drug and particle transport independently whilst human and pig skin were employed to determine skin delivery. KEY FINDINGS: The tocopheryl acetate, when loaded into the solid lipid nanoparticles, did not release from the particle. However, 1.65 +/- 0.90% of an infinite dose of tocopheryl acetate penetrated into the stratum corneum of pig skin when delivered using a nanoparticle-containing gel. CONCLUSIONS: These results suggest that hydration of the stratum corneum in pig skin could lead to the opening of hydrophilic pores big enough for 50 nm-sized particles to pass into the superficial layers of the skin, a phenomenon that was not repeated in human skin.

Lactobionic acid in a natural alkylpolyglucoside-based vehicle: assessing safety and efficacy aspects in comparison to glycolic acid.

BACKGROUND/AIMS: Lactobionic acid (LA) is a newer cosmeceutical active belonging to the class of alpha-hydroxyacids (AHAs), showing advantages over them. The aim of part I of this study was to compare efficacy and irritation potential of LA vs. glycolic acid (GA) from two types of vehicles - gel and emulsion. In part II, effects of LA-containing emulsions based on a new, natural emulsifier of alkylpolyglucoside (APG) type were evaluated. METHODS: Skin bioengineering was used on 77 healthy volunteers to assess: color as erythema and melanin (MI) index, transepidermal water loss, electrical capacitance and pH of the skin. In part I of the study, the parameters were measured after occlusion and periodically during 2 weeks of test samples application; in part II parameters were measured periodically during 4 weeks. RESULTS/CONCLUSION: LA-containing samples has produced better skin performance when compared with corresponding GA-containing ones, particularly the lack of both skin irritation and skin barrier impairment. When used in vehicles based on a new APG-emulsifier, LA and GA have shown better efficacy, emphasizing the importance of vehicle on the effects of topical actives. LA (6%) in the emulsion based on APGs could be proposed as an alternative to low-molecular AHAs in cosmeceuticals.

From conventional towards new - natural surfactants in drug delivery systems design: current status and perspectives.

IMPORTANCE OF THE FIELD: Surfactants play an important role in the development of both conventional and advanced (colloidal) drug delivery systems. There are several commercial surfactants, but a proportionally small group of them is approved as pharmaceutical excipients, recognized in various pharmacopoeias and therefore widely accepted by the pharmaceutical industry. AREAS COVERED IN THIS REVIEW: The review covers some of the main categories of natural, sugar-based surfactants (alkyl polyglucosides and sugar esters) as prospective pharmaceutical excipients. It provides analysis of the physicochemical characteristics of sugar-based surfactants and their possible roles in the design of conventional or advanced drug delivery systems for different routes of administration. WHAT THE READER WILL GAIN: Summary and analysis of recent data on functionality, applied concentrations and formulation improvements produced by alkyl polyglucosides and sugar esters in different conventional and advanced delivery systems could be of interest to researchers dealing with drug formulation. TAKE HOME MESSAGE: Recent FDA certification of an alkyl polyglucoside surfactant for topical formulation presents a significant step in the process of recognition of this relatively new group of surfactants. This could trigger further research into the potential benefits of naturally derived materials in both conventional and new drug delivery systems.

Eating chocolate can significantly protect the skin from UV light.

BACKGROUND: Cocoa beans fresh from the tree are exceptionally rich in flavanols. Unfortunately, during conventional chocolate making, this high antioxidant capacity is greatly reduced due to manufacturing processes. AIM: To evaluate the photoprotective potential of chocolate consumption, comparing a conventional dark chocolate to a specially produced chocolate with preserved high flavanol (HF) levels. METHODS: A double-blind in vivo study in 30 healthy subjects was conducted. Fifteen subjects each were randomly assigned to either a HF or low flavanol (LF) chocolate group and consumed a 20 g portion of their allocated chocolate daily. The minimal erythema dose (MED) was assessed at baseline and after 12 weeks under standardized conditions. RESULTS: In the HF chocolate group the mean MED more than doubled after 12 weeks of chocolate consumption, while in the LF chocolate group, the MED remained without significant change. CONCLUSIONS: Our study demonstrated that regular consumption of a chocolate rich in flavanols confers significant photoprotection and can thus be effective at protecting human skin from harmful UV effects. Conventional chocolate has no such effect.

Changes in skin physiology and clinical appearance after microdroplet placement of hyaluronic acid in aging hands.

BACKGROUND: Up to now rejuvenating treatment of the hands has been challenging and results often disappointing. AIMS: To determine whether hyaluronic acid (HA) microdroplet placement into the dorsal hands has an impact on skin physiology and clinical appearance and whether there is any difference between stabilized HA (S-HA) and nonstabilized HA (NS-HA). PATIENTS/METHODS: The intra-individual comparison in 15 volunteers involved injection sessions at week 0, 4, and 8 with random assignment of left and right hand to either S-HA or NS-HA. Skin physiology parameters cutaneous elasticity, surface roughness, hydration, and transepidermal water loss (TEWL) were measured in vivo at weeks 0 (before treatment), 4 (before subsequent treatment), 12, and 24. Clinical hand assessment was carried out at weeks 0 and 12 by a blinded dermatologist. RESULTS: Intradermal injection of S-HA generated significant improvement in skin elasticity and surface roughness at week 12 compared to baseline. On the hands treated with NS-HA, there was a trend for improvement (not significant). While there was no significant difference in hydration and TEWL between both hands before treatment, at week 12 hands treated with S-HA displayed a significantly higher hydration level and lower TEWL compared to NS-HA treatment. Clinically S-HA proved to be significantly superior to NS-HA. At week 24 the observed effects started to return back toward baseline, with S-HA treatment still offering better results compared to the NS-HA. CONCLUSIONS: Skin revitalization with injectable HA can improve clinical appearance and skin physiology parameters on the back of the hands. It has been shown that S-HA has better effects when compared with NS-HA.

Effects of lipid nanocarriers on the performance of topical vehicles in vivo.

BACKGROUND/AIMS: Nanocarrier systems have been extensively studied for their suitability in personal care formulations. Theoretically, they could enhance skin delivery of active compounds, thereby improving in vivo efficacy of the products. As such the aim of this study was to evaluate the effect of a lipid nanocarrier (LNC) system loaded with tocopheryl acetate (TA) on the hydration, biomechanical properties, and antioxidant capacity of human skin, when used in two different vehicles, and compare it with a non-LNC formulation. METHODS: TA-loaded lipid nanocarriers (TA-LNCs) were produced by the phase inversion method, using physiological lipids and purified by ultra-centrifugation. They were incorporated into a hydrophilic gel and foam, and their performance compared with a saturated TA solution in silicon oil. Skin hydration and biomechanical properties were measured by means of a corneometer and a cutometer, respectively, while a high-resolution spectrophotometer was used to assess skin redness after stimulation by methyl nicotinate in a micro-inflammatory test. Both short-term (3 h) and long-term trials (4 weeks) were performed. RESULTS: The results confirmed that the LNCs enhanced skin hydration in both studies, while skin viscoelastic parameters remained practically unchanged during the 4-week study. The antioxidant assessment failed to show significant difference between the test sites. CONCLUSIONS: TA-loaded LNCs exhibited the ability to enhance skin hydration, while their effect on skin biomechanical properties and on antioxidant efficacy could not be statistically proved.

Topical vehicles based on natural surfactant/fatty alcohols mixed emulsifier: The influence of two polyols on the colloidal structure and in vitro/in vivo skin performance.

There is a growing need for in-depth research into new skin- and environment-friendly surfactants, such as alkylpolyglucosides. The aim of this study was to assess whether, to which extent and by what mechanism the two commonly used hydrophilic excipients, propylene glycol (PG) and glycerol (GL), affect the colloidal structure of emulsions formed by a natural mixed emulsifier, cetearyl glucoside and cetearyl alcohol. Furthermore, the study was concerned with the effect of these changes on in vitro permeation profiles of two model drugs (diclofenac sodium and caffeine) and in vivo skin performance of the test samples. The results have shown that the emulsion vehicles consisted of a complex colloidal structure of lamellar liquid crystalline and lamellar gel crystalline type. PG addition produced a stronger hydrophilic lamellar gel phase than GL, which was independent on the model drug used. PG-containing vehicles have revealed a considerable amount of interlamellar PG/water mixture, with incorporated drug. In vitro permeation data obtained using artificial skin constructs (ASC) confirmed the relationship between rheological profiles of vehicles and the extent of skin delivery. Higher permeation profiles of both drugs from PG-containing formulations coincided with a higher increase in transepidermal water loss observed in in vivo study on human volunteers, which confirms the penetration/permeation enhancer effect of PG. It also indicates the existence of the vehicle/ASC interactions analogous to those between the vehicle and the skin, thus affirming the use of ASC as a reliable tool for permeation studies. Contrary to the effect of PG, the results obtained with GL suggest that it may have a permeation-retarding rather than a permeation-enhancing effect in topical vehicles of this type.