Search Results (147)

The lips, due to their unique anatomical characteristics of a thin stratum corneum, the absence of sebaceous glands, and limited melanin content are particularly vulnerable to ultraviolet (UV) radiation, necessitating specialized photoprotective care. While facial sunscreens are widely available, the development of lip-specific sun protection products remains underexplored. This study aims to analyze technological trends and innovations in lip photoprotection by reviewing patents published between 2014 and 2024. A comprehensive patent search using the IPC code A61Q19 and the keywords “lip” and “sunscreen” identified 17 relevant patents across China, the United States, and Japan. The patents were examined for active ingredients, formulation strategies, and use of botanical or sustainable excipients. The findings revealed that patented formulations predominantly rely on well-established UV filters such as zinc oxide, titanium dioxide, octyl methoxycinnamate, and avobenzone, often combined with antioxidants like ferulic acid and rutin for enhanced efficacy. Lipid-based excipients were widely used to improve texture, hydration, and product stability. Although many formulations exhibit a conservative ingredient profile, the strategic combination of UV filters with natural antioxidants and moisturizing lipids demonstrates a multifunctional approach aimed at enhancing both protection and user experience. Full article

Transdermal drug delivery (TDD) is an increasingly important non-invasive method for administering active pharmaceutical ingredients (APIs) through the skin barrier, offering advantages such as improved therapeutic efficacy and reduced systemic side effects. As demand increases for patient-friendly and minimally invasive treatment options, TDD has attracted substantial attention in research and clinical practice. This review summarizes recent advances enhancing skin permeability through chemical enhancers (e.g., ethanol, fatty acids, terpenes), physical (e.g., iontophoresis, microneedles, sonophoresis), and nanotechnological methods (e.g., liposomes, ethosomes, solid lipid nanoparticles, and transferosomes). A comprehensive literature analysis, including scientific publications, regulatory guidelines, and patents, was conducted to identify innovative methods and materials used to overcome the barrier properties of the stratum corneum. Special emphasis was placed on in vitro, ex vivo, and in vivo evaluation techniques for such as Franz diffusion cells for assessing drug permeation and skin interactions. The findings highlight the importance of active physical methods, passive nanostructured systems, and chemical penetration enhancers. In conclusion, integrating multiple analytical techniques is essential for the rational design and optimization of effective transdermal drug delivery systems. Full article

The aim of this study was to develop double emulsions-filled chitosan hydrogel beads for topical application and to elucidate their skin penetration behavior. Double emulsions were prepared by a two-step emulsification method, and double emulsions-filled chitosan hydrogel beads were prepared by the extrusion method. The structure, stability, and skin penetration behavior were investigated. The results of yield efficiency (above 80%) and microstructure observation confirmed the feasibility of the preparation method. After loading the hydrophilic active ingredients (vitamin C) into this system, the retention ratio after storage for 6 weeks increased by 77.6%. Furthermore, hydrogel beads could promote the permeation of hydrophilic active ingredients loaded in double emulsions. When the concentration of chitosan was 3% (w/v), the permeation coefficient of vitamin C from hydrogel beads exhibited an increase (1.7-fold) compared with double emulsions. This system could affect the orderliness of lipid structures in the stratum corneum. In addition, the results indicated that this system could be used for the topical delivery of hydrophobic active ingredients (quercetin) as well. This is the first report of chitosan bead stabilization of W/O/W emulsions, yielding a 2.6-fold increase in skin uptake of hydrophilic actives. Full article

Vulvar hygiene is an important part of general hygiene: the goals are to clear the vulvar area of microbial and cellular debris and vaginal and fecal secretions, ensure local comfort, provide natural levels of hydration, and protect the vulvar microbiota. There are few national and international guidelines on vulvar hygiene. We searched the PubMed database up until 30 November 2024, using logical combinations of the following terms: hygiene, washing, vulva, vulvar, microbiota, hydration, syndet, soap, detergent, water, and customs. The abstracts were reviewed, and potentially relevant full-text articles were retrieved and examined. The subregions of the vulva vary with regard to the presence of sweat and sebaceous glands, the keratin content, the water content, the pH, and the microbiota (notably Lactobacillus, Corynebacterium, Staphylococcus, and Prevotella). An alteration in the vulvar microbiota can cause an imbalance in the vaginal microbiota, and vice versa. Vaginal douching may have negative effects on vulvar microbiota. Hair removal might increase the risk of long-term dermatological complications. Repeated washing with water alone exposes the stratum corneum to damage, and washing with soap alters the stratum corneum proteins and lipids, increases skin water loss, and accentuates the risk of irritation. Syndet-based products have a mild detergent effect, promotion of hydration, a suitable pH for the vulvar area, and protection of the vulvar microbiota. Syndet-based products (containing a blend of surfactants, emollients, antioxidants, and buffering agents) appear to be the most appropriate for vulvar care. Full article

Transdermal drug delivery systems (TDDSs) provide a non-invasive alternative to oral and parenteral routes, delivering drugs into the bloodstream while avoiding gastrointestinal degradation and first-pass metabolism. Despite benefits like enhanced bioavailability and patient compliance, the stratum corneum limits drug permeation. Ethosomes overcome the stratum corneum barrier with superior flexibility and permeability compared to liposomes. Ethanol disrupts the skin’s lipid bilayer, enabling deep penetration and efficient drug delivery. Ethosomes offer high entrapment efficiency and stability, delivering both hydrophilic and lipophilic drugs. However, challenges like stability optimization and clinical translation persist. This review examines the structural components, preparation methods, and therapeutic applications of ethosomes in metabolic and chronic diseases, including diabetes, cardiovascular diseases, neurodegenerative disorders, arthritis, and cancers. Moreover, it highlights the potential of ethosomes to revolutionize TDDSs for managing chronic and metabolic diseases, providing a foundation for further research and clinical development. Full article

Background: Sensitive skin exhibits impaired skin barrier function. The lipid composition of the skin, a pivotal element within the stratum corneum’s “brick-and-mortar” structure, plays a dual role: it is integral to cell differentiation processes and serves as a vital nutrient reservoir for cutaneous microbiota, thereby influencing the skin’s microecological balance. There is a notable research gap concerning the comparative analysis of physiological parameters and lipid profiles among individuals with sensitive dry skin (SDS), sensitive oily skin (SOS), and healthy skin (HS). Methods: A total of 95 females (18–25 years) were grouped: SDS (n = 32), SOS (n = 31), and HS (n = 32). Stratum corneum water content, oil content, and TEWL were measured. Lipids from sebaceous glands and stratum corneum (tape-stripping) underwent UPLC-QTOF-MS analysis. Differential lipids were identified via OPLS-DA, volcano plots, and LMSD. Results: In terms of physiological indicators, notable disparities emerged in oil content and stratum corneum water content between the SOS and both the HS and the SDS. Sensitive skin, whether dry or oily, displayed a higher transepidermal water loss (TEWL) value than healthy skin, reflecting a declined state of skin barrier function. Regarding the sebum samples, the relative percentages of sphingolipids (SP) and glycerophospholipids (GP) were significantly higher in SDS. Regarding the stratum corneum samples, the percentages of SP in SDS were significantly higher. Conclusions: This study, for the first time, conducted a comprehensive analysis of the skin’s physiological properties, lipidomics of sebum, and stratum corneum lipids among groups with SDS, SOS, and HS. These observations indicate a profound association between skin barrier dysfunction in SDS individuals and, in particular, sphingolipids (SP). Full article

External environmental stressors and internal physiological changes frequently compromise the skin barrier, resulting in conditions such as dermatitis and dehydration. A key underlying factor is the depletion of ceramides, essential lipids in the stratum corneum that maintain skin integrity. Although topical ceramide supplementation is effective for barrier repair, its clinical application is limited by poor solubility and low skin permeability. To overcome these challenges, this study developed an oil-in-water nanoemulsion (O/W-NE) using ultrasonic emulsification for the efficient transdermal delivery of ceramide C2. Octyldodecanol was selected as the oil phase to enhance ceramide solubility, while glycerin was incorporated to increase aqueous phase viscosity, reduce particle size, and function as a biocompatible penetration enhancer. The optimized nanoemulsion achieved a particle size of 112.5 nm and an encapsulation efficiency of 85%. Its performance was evaluated via in vitro release, ex vivo skin permeation, and in vivo biocompatibility studies. Mechanistic investigations revealed that both particle size and glycerin concentration significantly influenced ceramide penetration into the epidermis and dermis. Additionally, the nanoemulsion exhibited moisturizing and barrier-repair effects in a damaged skin model. Overall, this O/W-NE offers a stable, non-invasive strategy for enhancing ceramide delivery and restoring skin barrier function. Full article

Background/Objectives: The topical delivery of antibiotics through transethosomes shows promise for enhancing its dermal delivery for the treatment of skin infections. This study aimed to develop and characterize azithromycin-loaded transethosomes to enhance topical drug delivery and improve the antibacterial activity of azithromycin. Methods: The prepared azithromycin formulations underwent assessment for various characteristics, including their vesicle dimensions, size distribution, zeta potential, encapsulation efficiency, and morphological features (via TEM analysis). Additionally, their thermal properties were examined through DSC analysis, and their stability was monitored over six months under refrigerated storage conditions. The sequential tape-stripping technique was employed to conduct ex vivo penetration studies on human skin. Interactions between transethosomes and stratum corneum lipids were examined using attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). Additionally, the formulations were tested for their in vitro antibacterial efficacy against Staphylococcus aureus. Results: The findings revealed that AZ 1 and AZ 2 had vesicle sizes of 108.44 ± 5.72 nm and 70.42 ± 6.02 nm, zeta potential measurements of −11.897 ± 1.820 mV and −34.575 ± 4.535 mV, and high entrapment efficiencies of 99.259 ± 0.086% and 99.560 ± 0.014%, respectively. Transmission electron microscopy (TEM) analysis confirmed the spherical nature of the vesicles, whereas differential scanning calorimetry (DSC) confirmed the successful encapsulation of azithromycin in transethosomes. The formulations exhibited acceptable physical stability at 4 °C for six months. Ex vivo studies revealed a significantly higher deposition of azithromycin in the skin by both transethosome formulations than by the drug solution (p < 0.05), with low systemic absorption. Among the formulations, AZ 2 resulted in much deeper skin penetration, with deeper dermal and epidermal layer deposition (1.388 ± 0.242 µg/cm²) compared to AZ 1 (four-fold higher, p < 0.05) and to the control drug solution (12 times more, p < 0.05). Analysis using ATR-FTIR suggested that azithromycin-loaded transethosomes improve the drug penetration by increasing the lipid fluidity and extracting lipids from the stratum corneum. Moreover, the transethosomes loaded with azithromycin demonstrated enhanced antibacterial efficacy against Staphylococcus aureus, with minimum inhibitory concentration (MIC) values that were lower than those of the free drug solution. Conclusion: The results highlight the promising potential of transethosomes as a novel topical drug delivery system for azithromycin that offers improved therapeutic effects against skin infections Full article

The use of topical and transdermal drug delivery systems for nonsteroidal anti-inflammatory drugs (NSAIDs) has transformed pain management, inflammation, and skin conditions. This analysis highlights the topical and transdermal applications of ibuprofen, ketoprofen, and flurbiprofen, highlighting their excellent skin permeability and localized pain relief, as well as an evaluation of their safety in such applications. Their compatibility with diverse formulations, minimal systemic side effects, and widespread use in commercial products makes them ideal candidates for skin research and targeted therapy. Advances in transdermal delivery processes, such as the use of chemical enhancers, Solid Lipid Nanoparticles, vesicular systems, and hydrogels, have enhanced NSAID penetration and bioavailability. Physical techniques like iontophoresis and sonophoresis further enhance the transport of drugs across the stratum corneum of the skin. These approaches and processes enable more efficient and localized treatment of inflammatory conditions. The review emphasizes the need for continued innovation, interdisciplinary processes, and collaboration to overcome existing challenges. Future developments in nanotechnology and advanced drug delivery systems have the capability to enhance the effectiveness and safety of NSAIDs, paving the way for novel therapeutic solutions in managing pain and inflammation. Full article

Nano-drug delivery systems provide targeted solutions for addressing various drug delivery challenges, leveraging nanotechnology to enhance drug solubility and permeability. Liposomes, explored for several decades, face hurdles, especially in oral delivery. Bile-acid stabilized vesicles (bilosomes) are flexible lipid vesicles, composed of phospholipids or other surfactants, along with amphiphilic bile salts, and they show superior stability and pharmacokinetic behavior in comparison to conventional vesicular systems (liposomes and niosomes). Bilosomes enhance skin penetration, fluidize the stratum corneum, and improve drug stability. In oral applications, bilosomes overcome drawbacks, offering improved bioavailability, controlled release, and reduced side effects. Vaccines using bilosomes demonstrate efficacy, and bilosomes for intranasal, inhalation, ocular, and buccal applications enhance drug delivery, offering targeted, efficient, and controlled activities. Formulations vary based on active substances and optimization techniques, showcasing the versatility and potential of bilosomes across diverse drug delivery routes. Therefore, the aim of this comprehensive review was to critically explore the state-of-the-art of bilosomes in drug delivery and potential therapeutic applications. Full article

Exposure to ultraviolet (UV) radiation is a major contributor to skin injury, including sunburn, photoaging, and augmented risk of skin cancer, primarily through the generation of reactive oxygen species (ROS) that induce oxidative stress. Rosmarinic acid (RA), a natural phenolic compound with antioxidant and several other biological properties, has shown promise in mitigating such damage when incorporated into sunscreens. We evaluated RA’s possible interactions and potential to enhance the efficacy of three worldwide known UVB filters—ethylhexyl methoxycinnamate (EHMC), octocrylene (OCT), and ethylhexyl salicylate (EHS). The performance of sunscreens with and without RA (0.1% w/w) was analyzed through in vitro and in vivo photoprotective assessments. The HPLC-TBARS-EVSC (high-performance liquid chromatography—thiobarbituric acid reactive substances—ex vivo stratum corneum) protocol, which quantified oxidative stress reduction in the human stratum corneum, was also used. The in vitro photoprotective assays showed that RA had distinct levels of interactions with the UVB filters. When associated with EHMC, RA exclusively acted in the UVB range (SPF-enhancing effect). Remarkably, for EHS, RA contributed to a higher efficacy profile in the total UV spectrum. OCT-RA was the sample that reached the highest critical wavelength value parallelly to OCT, boosting the in vivo SPF by more than 157% in comparison to OCT. However, its in vitro SPF performance was not affected by the RA addition, being comparable to OCT, EHS, and EHS-RA. Furthermore, the HPLC-TBARS-EVSC protocol highlighted RA’s ability to reduce lipid peroxidation, with OCT-RA exhibiting the most notable protective effect. These findings underscore RA’s potential as a multifunctional additive in sunscreen systems, enhancing both photoprotection and oxidative stress mitigation. Full article

Objectives: This study aimed to identify and develop a novel, safe, and effective transdermal penetration enhancer derived from the leaves of Perilla frutescens (L.) Britt, and to explore the underlying mechanisms of its penetration enhancement effects. Methods: To evaluate the safety profile of the penetration enhancer, both skin irritation tests and histopathological analyses were conducted. The transdermal enhancement capabilities of the penetration enhancer were assessed in vitro using five model drugs. Furthermore, to gain insights into the penetration enhancement mechanism of this novel penetration enhancer, a range of analytical methods were used, including a spectroscopic technique, differential scanning calorimetry, micro-optical techniques, and molecular docking simulations. Results: Perilla essential oil contained 93.70% perilla ketone (PEK), which exhibited a safety profile superior to that of azone. PEK significantly increased the cumulative skin permeation of all the model drugs (p < 0.05). PEK exhibited the most obvious impact on puerarin penetration, with quantitative enhancement ratios of 2.96 ± 0.07 and 3.39 ± 0.21 at concentrations of 3% and 5% (w/v), respectively. A strong correlation between the enhancement effect of PEK and the physicochemical properties of the drugs was observed. Mechanistic studies revealed that PEK facilitates drug distribution from the solution phase to the stratum corneum (SC). Conclusions: PEK, seldom discussed in former studies, was observed to show extensive penetration enhancement effects by inducing conformational changes in SC lipids and disrupting the tightly ordered bilayer arrangement of lipids. These findings highlight the potential of PEK as a promising and safe natural transdermal penetration enhancer. Full article

Niacinamide, a derivative of vitamin B3, has been shown to reduce skin pigmentation (i.e., acting as a brightening agent) and inflammatory responses such as dermatitis and acne vulgaris. However, niacinamide is a hydrophilic compound and poor partitioning to the lipid matrix in the uppermost layer of the skin (the stratum corneum or SC) limits its delivery to the skin. This necessitates the use of penetration enhancers to increase its bio-availability. In this study, we used computer simulations to investigate the skin penetration of niacinamide alone and in combination with other brightening agents that are also shown to be skin penetration enhancers, namely undecylenoyl phenylalanine (Sepiwhite^®), bisabolol, or sucrose dilaurate. Molecular dynamics simulations were performed to reveal molecular interactions of these brightening agents with a lipid bilayer model that mimics the SC lipid matrix. We observed minimal penetration of niacinamide into the SC lipid bilayer when applied alone or in combination with any one of the three compounds. However, when all three compounds were combined, a notable increase in penetration was observed. We showed a 32% increase in the niacinamide diffusivity in the presence of three other brightening agents, which also work as penetration enhancers for niacinamide. These findings suggest that formulations containing multiple brightening agents, which work as penetration enhancers, may improve skin penetration of niacinamide and enhance the effectiveness of the treatment. Full article

The inherent acidic nature of the stratum corneum (SC), the so-called “acid mantle”, has a multitude of effects on skin barrier integrity owing to its (patho)physiological role in skin homeostasis, antimicrobial defense, and inflammation. Several salient SC acidifying mechanisms, including the breakdown of FLG (filaggrin) protein, lipid processing, and the activity of the sodium proton pump SLC9A1/NHE1, are indispensable for the structural and functional integrity and cohesion of the SC as they contribute immensely to the origin, generation, maintenance, and overall SC acidification of the skin surface pH (pHss). As many endogenous and exogenous factors can affect the pHss, the pHss can inevitably deviate from its optimum. The elevation of the pHss is often accompanied by abnormalities in SC lipid metabolism and organization, SC cohesion, and SC integrity and is commonly observed in eczema, which is associated with symptoms of dry skin, inflammation, pruritus, and infection. In psoriasis, it seems that the pHss is altered as well; however, in this case, it is likely to be lower than the physiological pHss. Due to the negative effects of an altered pHss in both eczema and psoriasis, it has been suggested to maintain the pHss at physiological levels by utilizing pH-balanced topical cleansers and moisturizers that can improve the skin’s structural and functional integrity by benefiting skin moisturization and the regeneration and organization of the SC barrier. The principal aim of this review is to gather an understanding of the existing research and to stimulate critical thinking and inspire innovative ideas about ‘known unknowns’, considering the origin, intricate nature, and prime role of the pHss in human skin health, as well as the pathogenesis of eczema and psoriasis. Full article

Information on skin barrier in horses is limited. A study on the epidermal ultrastructure of normal and allergic horses documented disorganized amorphous intercellular lipids in the stratum corneum of allergic samples. These findings are similar to atopic canine and human skin. Currently, there is no published study comparing skin barrier function parameters between normal and allergic horses; thus, the functional implications of the ultrastructural changes are unknown. In normal horses, body location, gender, breed, and ambient conditions affect skin barrier parameters, such as Transepidermal Water Loss. Skin microbiome studies on normal horses have highlighted the importance of season and environmental conditions, since horses housed together share similar microbiomes. Skin dysbiosis and predominance of staphylococcus have been described in horses with pastern dermatitis. Transcriptomic studies of the epidermis of normal and allergic horses have found that lesional allergic skin has substantial transcriptomic differences when compared with healthy skin, namely downregulation of genes of tight junctions, keratins, and upregulation of serine proteases and IL-13. Keratinocytes harvested from horses with insect bite hypersensitivity show upregulation of IL-31 gene expression under stimulation. While more research is clearly needed, preliminary results seem to support skin barrier differences between normal and allergic horses. Full article