HYDROGENATED LECITHIN

Functional cosmetic materials with anti-aging properties, such as wrinkle reduction, often struggle to penetrate the skin's stratum corneum (skin barrier). Therefore, to exert anti-aging effects, these materials must pass through the skin barrier and reach fibroblasts in the dermal layer. In this study, deformable liposomes were developed for efficient transdermal delivery of retinol, a well-known anti-wrinkle agent. Five formulations (ML-1 to ML-5) were prepared using hydrogenated lecithin (HL) and mannosylerythritol lipid (MEL) as an edge activator with HL:MEL mass ratios of 10:0, 7:3, 5:5, 3:7, and 0:10. Their physicochemical properties, including particle size, zeta potential, polydispersity, encapsulation efficiency and deformability index were analyzed. For the optimal formulation, the liposome morphology was observed using cryo-TEM, and the retinol skin penetration ability of each liposome formulation was evaluated using a Franz diffusion cell. Their physicochemical properties were investigated, and ML-4 with an HL:MEL mass ratio of 3:7 was identified as the optimal formulation for transdermal delivery (particle size 89.3±6.8 nm, zeta potential -25.2±1.1 mV, polydispersity index 0.263±0.012, encapsulation efficiency 86.3±2.3%, and deformability index 5.76±1.9). Cryo-TEM analysis confirmed the liposomal morphology of ML-4. The retinol skin penetration ability of each formulation was evaluated using the Franz diffusion cell, with the conventional liposome (ML-1) without MEL as the control. The ML-4 formulation achieved a total retinol penetration of 29.0%, a 10.6% increase compared to ML-1 (18.4%). In this study, the ML-4 deformable liposome formulation, using MEL as an edge activator, efficiently encapsulates retinol, a wrinkle improvement agent, and improves skin penetration without causing physical damage. These findings suggest that ML-4 can serve as an efficient transdermal delivery system for functional cosmetic materials.

Innovation is considered a determining factor in the highly competitive environment of the cosmetic industry to introduce products while creating new needs. The goal of the study consisted of developing a highly natural and minimalist emulsion with sensorially pleasant skin application highlighted by an innovative ingredient based on a Ca 2+ double cone vector system. The desired product characteristics include a creamy, white texture that is not too greasy or excessively whitening, with rapid skin penetration to facilitate its use for skin treatment. To determine the ideal composition of the emulsion, a design of experiment (DoE) based strategy was applied in two steps: a screening step followed by optimisation. The screening step aimed to identify the key potential ingredients and process parameters that have a significant impact on the rheological and textural properties of the emulsion. The optimisation step provided the final emulsion formula with the desired physicochemical parameters and sensory characteristics. After rheological and sensory analysis, the screening of different ingredients revealed that the combination of 0.8% xanthan gum as the thickening agent (TA), glyceryl stearate citrate and polyglyceryl-3 stearate and hydrogenated lecithin as surfactant S1, and 1% of a mixture of C15-19 alkane (plant-based and renewable) - coco-caprylate/caprate as the sensory agent (SA1) provided the best sensorial qualities for the emulsion. The study demonstrated that the deflocculating rod met one of optimisation's target criteria through its process effect. Based on DoE, the final formulation resulted in a visually white formulation that was neither too greasy nor excessively whitening and highly penetrative of the skin, offering a comfortable face or body cream application for adults and children. L'innovation est considérée comme un facteur déterminant dans l'environnement hautement concurrentiel de l'industrie cosmétique, permettant d'introduire de nouveaux produits tout en créant de nouveaux besoins. L'objectif de cette étude est de développer une émulsion très naturelle et minimaliste, offrant une application sensorielle agréable sur la peau, mise en valeur par un ingrédient innovant basé sur un système vecteur en double cône de Ca 2+ . Les caractéristiques recherchées pour le produit incluent une texture crémeuse et blanche, pas trop grasse, ni excessivement blanchissante, avec une pénétration cutanée rapide facilitant son utilisation dans les soins de la peau. MÉTHODES: Pour déterminer la composition idéale de l'émulsion, une stratégie basée sur la méthodologie du plan d'expériences (Design of Experiment, DoE) a été appliquée en deux étapes: une étape de criblage suivie d'une optimisation. L'étape de criblage visait à identifier les principaux ingrédients potentiels et les paramètres du procédé ayant un impact significatif sur les propriétés rhéologiques et texturales de l'émulsion. L'étape d'optimisation a permis d'obtenir la formule finale de l'émulsion avec les paramètres physico‐chimiques et les caractéristiques sensorielles souhaités. RÉSULTATS: Après les analyses rhéologiques et sensorielles, le criblage des différents ingrédients a révélé que la combinaison de 0,8 % de gomme xanthane comme agent épaississant (TA) (glycéryl stéarate citrate (et) polyglycéryl‐3 stéarate (et) lécithine hydrogénée) comme tensioactif S1, et 1 % d'un mélange d'alcane C15‐19 (d'origine végétale et renouvelable) ‐ coco‐caprylate/caprate comme agent sensoriel (SA1) apportait les meilleures qualités sensorielles à l'émulsion. L'&#

Lecithin is a generic term that is often used to indicate a product mainly constituted of phospholipids. Lecithins can be used in pharmaceutical and cosmetic field as wetting agents, emulsifiers and building blocks for the production of liposomes and micelles. One of its main sources are plants. From their extraction a final product mainly constituted of phosphatidylcholines and phosphatidylethanolamines can be obtained. Common issue connected to freshly extracted lecithins is the presence of a product rich in double bonds subject to photo and air oxidation. By adding in the purification process a further catalytic step, it is possible to form stable hydrogenated lecithin products. Despite their widespread use, little is known about the physicochemical properties of such hydrogenated lecithins, detailed studies mainly based on X-ray scattering methods on mono- and multi-layers have been performed. Additionally, the emulsifying properties of these lecithins such as Hydrophilic-Lipophilic Deviation (HLD parameter) and solubility have also been studied. General findings are that mixtures with higher amounts of phosphatidylcholines (90-100 %) formed a well-defined lamellar phase showing in monolayers complete absence of charge, while lecithins with lower phosphatidylcholine contents (75-80 %) formed charged monolayers and positionally uncorrelated bilayers due to the presence of charged species. The hydrogenated phospholipids (PLs) studied were highly soluble in several co-solvents which are suitable for the incorporation of these phospholipids into relevant dermal formulations. The studied PLs are able to stabilize innovative dermal colloidal formulations such as cerosomes and to improve the incorporation of them into Stratum corneum models. In conclusion, the following studies will allow a more rational selection of hydrogenated lecithins for the formulation of cosmetic and pharmaceutical products.

I have been studying the improvement of drug solubility using solid dispersion and skin-applied formulations. When preparing solid dispersions using phosphatidylcoline (PC) as a carrier, drug with hydrogen-donating groups interacts with PC to produce amorphous solid dispersions with high drug content; this overcomes improves drug absorption. The drug was solubilized and supersaturated in the oil-based gel formed with hyadrogenated lecithin; this facilitates drug permeation through the skin. The promoting effect differs with the nature of the oil used because of the skin penetration of the oil itself and the accompanying increase in drug solubility and diffusion coefficient in the skin. At actual application volumes of 10 µL/cm 2 or less, the skin penetration of poorly-absorbable drugs depends on the molecular weight and surface tension of the oil. The penetration of the oil vehicle into the upper stratum corneum influences the reach of the drug into the stratum corneum; a high drug concentration near the 7th layer of the stratum corneum promotes migration through the skin by increasing the linear concentration gradient in deeper layers. In addition, we performed a risk assessment, in collaboration with toxicologists, for dermal safety that included the toxicity potential of substances and the parts related to skin transfer.

Liposomes are self-assembled spherical systems composed of amphiphilic phospholipids. They can be used as carriers of both hydrophobic and hydrophilic substances, such as the anti-aging and wound-healing copper-binding peptide, GHK-Cu (glycyl-L-histidyl-L-lysine). Anionic (AL) and cationic (CL) hydrogenated lecithin-based liposomes were obtained as GHK-Cu skin delivery systems using the thin-film hydration method combined with freeze-thaw cycles and the extrusion process. The influence of total lipid content, lipid composition and GHK-Cu concentration on the physicochemical properties of liposomes was studied. The lipid bilayer fluidity and the peptide encapsulation efficiency ( EE ) were also determined. Moreover, in vitro assays of tyrosinase and elastase inhibition were performed. Stable GHK-Cu-loaded liposome systems of small sizes (approx. 100 nm) were obtained. The bilayer fluidity was higher in the case of cationic liposomes. As the best carriers, 25 mg/cm 3 CL and AL hydrated with 0.5 mg/cm 3 GHK-Cu were selected with EE of 31.7 ± 0.9% and 20.0 ± 2.8%, respectively. The obtained results confirmed that the liposomes can be used as carriers for biomimetic peptides such as copper-binding peptide and that the GHK-Cu did not significantly affect the tyrosinase activity but led to 48.90 ± 2.50% elastase inhibition, thus reducing the rate of elastin degeneration and supporting the structural integrity of the skin.

This study was performed to investigate the application of pluronic lecithin organogel (PLO gel) in cosmetics as a topical drug delivery system. PLO gel was known as transdermal drug delivery systems. It has a very interesting system, owing to their biocompatibility; their amphiphilic nature, facilitating dissolution of various drug classes; and their permeation enhancement properties. We realized that PLO gel has a critical shortcoming of flowability at low temperatures to be used as a cosmetic ingredient. To improve this drawback, this study aimed to find an appropriate quantity of three main compositions of PLO gel, including aqueous phase (poloxamer 407 and water), polyol phase (PEG-400), and oil phase (lecithin and oil), and applied an experimental design using the response surface methodology (RSM). We assessed the elapsed time change by temperature in each PLO gel formulation, observed the morphology of PLO gel using field emission scanning electron microscope (FE-SEM), and determined the gelation point by using differential scanning calorimetry (DSC). Rheology measurements to assess viscoelastic properties were determined by using a rheometer, and skin permeation efficiency was assessed by diffusion system. It was confirmed that three main factors (hydrogenated lecithin, PEG-400, and poloxamer 407) of PLO gel should be balanced without flowability even in cold temperature. Through the RSM, it was assumed that the most effective ingredient was PEG-400 at PLO gel formulation and physical properties. The PLO gel formulation (hydrogenated lecithin 5.0%, PEG-400 20.0%, and poloxamer 407 15.0%) was evaluated as the most suitable formulation for use in cosmetics due to its viscosity and elasticity results. The shape was observed through FE-SEM, and it was confirmed that the PLO gel forms a polymeric bicontinuous microemulsion structure. Regarding the applicability of PLO gel in cosmetics, we verified that PLO gel can be used in a delivery system for active substances. The study findings suggest that PLO gel can be used as one of the ingredients in cosmetic formulations.

In this study, we evaluated different strategies to optimize the percutaneous absorption of niacinamide (NA) and soy phytosterols (FITO) by making use of solid lipid nanoparticles (SLN) and penetration enhancers, such as the hydrogenated lecithin. The evaluation of the skin permeation of NA and FITO has been effected in vitro using excised human skin (i.e., stratum corneum-epidermis or SCE). Furthermore, we evaluated the in vivo effect that NA and FITO has on skin barrier recovery after the topical application; using the extent of methyl nicotinate (MN)-induced erythema in damaged skin as a parameter to determine the rate of stratum corneum recovery. Results pointed out the importance of these strategies as valid tools for NA and FITO topical delivery. In fact, soy lecithin based formulations were able to increase the percutaneous absorption of the two active ingredients, while SLN guaranteed an interesting delayed and sustained release of FITO. In vivo evaluation showed clearly that the formulation containing both the actives (NA and FITO) is able to recover about 95% of skin barrier integrity eight days after tape stripping. This effect is probably due to the "synergistic effect" of NA and FITO.

Liquid crystalline nanoparticles (LCNs) were prepared using glyceryl monooleyl ether (GME) by the modified film rehydration method. Hydrogenated lecithin (HL), 1,3-butylene glycol (1,3-BG), and Poloxamer 407 were used as additives. The prepared LCN formulations were evaluated based on particle size, small-angle X-ray diffraction (SAXS) analysis, (1)H- and (19)F-NMR spectra, and in vitro skin permeation across Yucatan micropig skin. The composition (weight percent) of the LCN formulations were GME-HL-1,3-BG (4 : 1 : 15), 4% GME-based LCN and GME-HL-1,3-BG (8 : 1 : 15), 8% GME-based LCN and their mean particle sizes were 130-175 nm. Flurbiprofen 5 and 10 mg was loaded into 4% GME-based LCN and 8% GME-based LCN systems, respectively. The results of SAXS and NMR suggested that both flurbiprofen-loaded formulations consist of particles with reverse type hexagonal phase (formation of hexosome) and flurbiprofen molecules were localized in the lipid domain through interaction of flurbiprofen with the lipid components. Flurbiprofen transport from the LCN systems across the Yucatan micropig skin was increased compared to flurbiprofen in citric buffer (pH=3.0). The 8% GME-based LCN systems was superior to the 4% GME-based LCN for flurbiprofen transport. Since the internal hexagonal phase in the 8% GME-based LCN systems had a higher degree of order compared to the 4% GME-based LCN in SAXS patterns, the 8% GME-based LCN system had a larger surface area, which might influence flurbiprofen permeation. These results indicated that the GME-based LCN system is effective in improving the skin permeation of flurbiprofen across the skin.

The aim of this study was to assess the ability of some vehicles (emulsion and emulgel), containing hydrogenated lecithin as penetration enhancer, in increasing the percutaneous absorption of the two model compounds dipotassium glycyrrhizinate (DG) and stearyl glycyrrhetinate (SG). Furthermore SG-loaded solid lipid nanoparticles (SLNs) were prepared and the effect of this vehicle on SG permeation profile was evaluated as well. Percutaneous absorption has been studied in vitro, using excised human skin membranes (i.e., stratum corneum epidermis or [SCE]), and in vivo, determining their anti-inflammatory activity. From the results obtained, the use of both penetration enhancers and SLNs resulted in being valid tools to optimize the topical delivery of DG and SG. Soy lecithin guaranteed an increase in the percutaneous absorption of the two activities and a rapid anti-inflammatory effect in in vivo experiments, whereas SLNs produced an interesting delayed and sustained release of SG.

This study investigated the development and characterization of trans-resveratrol-loaded transfersomes, with and without cholesterol, for potential non-irritating dermal applications. Transfersomes were prepared using thin-film hydration combined with probe sonication, incorporating hydrogenated lecithin, cholesterol, and Tween ® 60 in six different ratios. The formulations were characterized for their physicochemical properties, including particle size, polydispersity index, zeta potential, entrapment efficiency, morphology, in vitro release profiles, dermal permeation potential, and safety profile. All formulations exhibited particle sizes below 150 nm and zeta potentials below -30 mV, indicating favorable characteristics for dermal delivery. Cholesterol incorporation significantly increased particle size and enhanced zeta potential (p<0.05). Formulations containing 3-3.5% w/v hydrogenated lecithin achieved superior entrapment efficiency (>90%) compared to those with lower lecithin content (p<0.05), regardless of cholesterol incorporation. Transfersomes containing cholesterol displayed morphology with well-defined edges compared to cholesterol-free formulations. In vitro release studies revealed distinct release profiles, with cholesterol-free formulations releasing 70-83% of trans-resveratrol over 24 hours, compared to only 0-30% for cholesterol-containing formulations. Strat-M ® membrane-based permeation studies confirmed enhanced trans-resveratrol delivery across all transfersomal systems compared to the saturated solution (p<0.05), though cholesterol showed no significant impact on permeation efficiency. These findings indicate that cholesterol influences release profile but has limited effect on permeation efficiency. Safety assessment using the Hen's Egg Test-Chorioallantoic Membrane (HET-CAM) assay classified the developed transfersomes as weak irritants, indicating their dermal safety. Notably, formulation F3, with a hydrogenated lecithin to cholesterol to Tween 60 ratio of 6:0:4, emerged as the optimal candidate, achieving the highest release rate (80.24% over 24 hours) while maintaining favorable permeation compared to control. These findings feature the potential of transfersomal systems, particularly cholesterol-free variants, as promising carriers for the effective and safe dermal delivery of trans-resveratrol.

Liquid crystal emulsion is a new type of emulsion, in which the emulsifier molecules are located at the oil/water (O/W) interface and form a long-range ordered and short-range disordered lamellar liquid crystal. The lamellar liquid crystal formed by the emulsifier is similar to the skin stratum corneum lipid structure, which enables it to have a broad application prospect in the fields of cosmetics, pharmaceuticals, etc. In this work, a liquid crystal nanoemulsion was obtained by passing a liquid crystal emulsion stabilized by hydrogenated lecithin and phytosterol combination through a microfluidizer. The microstructure of the prepared liquid crystal nanoemulsion was investigated experimentally by dynamic light scattering, transmission electron microscopy, and small-angle X-ray scattering. The results have shown that the nanoemulsion inherited the liquid crystal emulsion property, namely, the long-range ordered and short-range disordered lamellar structure still existed at the oil/water interface even though they underwent extrusion, friction, and acceleration. At the same time, the underlying mechanisms of the existence of lamellar liquid crystal between the oil phase and the water phase for the nanoemulsion were explored theoretically by molecular dynamics simulations. The simulation results elucidated that the hydrogenated lecithin and phytosterol combination improved the flexibility of the bilayer structure composed of emulsifiers. The bilayers were the basic structure units of lamellar liquid crystals, and thus, the improved flexibility of bilayers provided insurance for the existence of lamellar liquid crystals with larger curvature around the oil droplets. In addition, the applicable properties of liquid crystal nanoemulsion were studied, and the results have shown that the liquid crystal nanoemulsion presented better slow-release and moisturizing properties than traditional nanoemulsions due to the existence of multilayers between oil and water phases. This work not only provides necessary information for the development and effective application of liquid crystal emulsions but also is helpful for in-depth understanding the inner properties of lamellar liquid crystal at molecular level.

Liquid crystals (LCs) are widely used for drug delivery due to their controlled and sustained drug release properties. In this paper, drug crystallization encapsulated liquid crystal emulsion, a novel drug delivery system, was proposed. The lamellar liquid crystals formed by hydrogenated lecithin, which are similar to the skin stratum corneum lipid structure, are adopted as the drug carrier to encapsulate non-steroidal anti-inflammatory drugs (NSAIDs). As the model drug, ketoprofen exists in the hydrophobic core of emulsion as a drug crystal when squalane is used as the oil phase. The microstructure, sustained drug release behaviors, physicochemical property and biocompatibility of the system were examined by polarized light microscopy, rheological measurements, differential scanning calorimetry, X-ray diffraction, small-angle X-ray scattering, in vitro release study, and in vitro cellular cytotoxicity assay. The results have shown that the novel system lowers the drug crystal melting point and improves the thermal stability of liquid crystal structure. Besides, the excellent biocompatibility and sustained release property through the additional dissolution step of drug crystal show its application potentials in the topical cosmeceuticals. The results will also be helpful for in-depth understanding of the physical state of encapsulated drug in the liquid crystal carrier systems.