Search Results (178)

Antibiotic residues in poultry pose health and resistance risks, necessitating breed-specific WDTs. In this study, the residue elimination patterns of seven antibiotics in Taihang chicken tissues under free-range conditions were studied and the appropriate WDT was formulated. A total of 240 healthy Taihang chickens aged 100 days were randomly divided into 8 groups, each comprising 30 chickens. Chickens in groups 1 to 7 were administered oxytetracycline, chlortetracycline, erythromycin, tylosin, tylvalosin, lincomycin, and tiamulin, respectively. Regarding the administration method, we adopted the highest dose and maximum course of treatment recommended by the Veterinary Pharmacopoeia of the People’s Republic of China. Group 8 served as the control group. Muscle, sebum, liver, and kidney samples were collected at 4 h, 1 d, 2 d, 3 d, 5 d, 7 d, 10 d, 13 d, and 16 d after drug withdrawal. Our results demonstrated that the drug residues after drug withdrawal gradually decreased with the increase in drug withdrawal days, and the elimination rate in the early stage of drug withdrawal was significantly faster than that in the later stage. At 4 h after drug withdrawal, the drug residues in various tissues reached their highest values. In most cases, the drug concentrations in the kidney and liver were higher than those in the muscles and sebum; however, some drugs also exhibited concentration peaks in the sebum. On the first day of drug withdrawal, the amount of residues in various tissues decreased rapidly. In general, the elimination rate of various drugs in the muscles, liver, and kidneys is faster but slower in the sebum. Based on the WDT calculation software WT1.4, the recommended WDTs for oxytetracycline, chlortetracycline, erythromycin, tylosin, tylvalosin, lincomycin, and tiamulin chickens are 4 d, 5 d, 11 d, 8 d, 13 d, 13 d, and 7 d, respectively. These findings support food safety and industry development. Full article

Background: Melasma is an acquired hyperpigmentation disorder with multifactorial etiologies and limited response to conventional therapies. Recent evidence suggests that Botulinum Toxin A (BoNT-A) may modulate ultraviolet (UV)-induced pigmentation and offer therapeutic benefits. Objective: We sought to evaluate the efficacy and safety of two intradermal dilutions of Letibotulinum toxin A (LetiBoNT-A) in Thai patients with melasma. Methods: In this randomized, double-blind, split-face study, 30 participants aged 32–62 years received a single intradermal injection of LetiBoNT-A, with 20 units administered per cheek. A 1:5 dilution was injected on one side of the face, and a 1:10 dilution was injected on the contralateral side. Outcomes were evaluated over a 6-month period using the Hemi-modified Melasma Area and Severity Index (Hemi-mMASI), VISIA^® brown spot analysis, and quantitative assessments of skin texture. Results: Both dilutions significantly improved Hemi-mMASI scores (1:5, p = 0.043; 1:10, p = 0.002) and brown spots (1:5, p = 0.002; 1:10, p < 0.001). The 1:10 dilution showed earlier and more sustained improvements. Subgroup analysis revealed greater reductions in Hemi-mMASI scores among patients with telangiectatic melasma, particularly with the 1:10 dilution, though they were not statistically significant. Additionally, the 1:10 dilution significantly reduced pore volume, pore area, and sebum levels. One case of transient facial asymmetry was reported with the 1:5 dilution. Conclusions: LetiBoNT-A is a safe and effective adjunct in melasma treatment. The 1:10 dilution offered superior clinical outcomes. Full article

Squalane (SQ, a saturated, sebum-mimetic hydrocarbon), oleic acid (OA, a monounsaturated fatty acid), and linoleic acid (LA, a polyunsaturated essential fatty acid) belong to the category of “lipids and fats” in cosmetic materials, and are widely employed as skin-conditioning emollients. However, they present differences in UV stress. In this study, we compared their effects on UV-induced oxidative damage, inflammation, and lipid metabolism using a mouse model and human sebaceous gland cells (SZ95). Results showed that 10% SQ did not worsen oxidative damage or inflammation after 6 weeks of UV exposure. In contrast, the 5% and 10% OA/LA groups showed increased skin wrinkling (p < 0.01), epidermal thickening (p < 0.05), and sebaceous gland atrophy. Transcriptome analysis indicated OA/LA upregulated arachidonic acid-related cytokine pathways (PTGS2/IL-1β; p < 0.001). In SZ95 cells, 0.006% OA/LA significantly increased lipid droplet formation (p < 0.001), free fatty acid (FFA) levels (p < 0.001), and pro-inflammatory gene expression (p < 0.001). Conversely, SQ neither promoted lipid droplet/FFA secretion nor induced oxidative stress. These findings suggest that high concentrations of unsaturated fatty acids in skincare may worsen lipid dysregulation and inflammation, while formulations based on saturated hydrocarbons like SQ could provide superior photoaging management by stabilizing skin barrier function. Full article

Background/Objectives: Treatment options for androgenic alopecia are still very limited and lack long-term efficacy. Dutasteride (DUT) has gained interest as a potent inhibitor of 5α-reductase, allowing for spaced applications, but DUT oral intake can cause serious adverse effects. Herein, we developed, characterized, and assessed the potential of DUT-loaded ethosomes with increasing ethanolic concentrations for hair follicle (HF) targeting to treat androgenic alopecia, hypothesizing that ethanol’s interaction with HFs’ sebum might increase DUT targeting to the HFs. Methods: Ethosomes were obtained using the water-dropping method. After a hydrodynamic size screening, a 30% ethanol concentration was fixed. Ethosomes with 30% ethanol were also prepared and had their ethanolic content removed by rotary evaporation for the evaluation of ethanol in targeting DUT to the HFs. The targeting factor (Tf) was calculated as the ratio between the DUT amount in HFs and the total DUT amount recovered from all skin layers after in vitro porcine skin penetration tests for 12 and 24 h. Results: The ethanolic concentration affected the vesicles’ size and the targeting potential. While the dried ethosomes could not increase DUT accumulation in the HFs at both time points (Tf: 0.27 in 12 h and Tf: 0.28 in 24 h), the presence of 30% ethanol in the vesicles increased the Tf from 0.28 (12 h) to 0.34 (24 h), significantly superior (p < 0.05) than the dried ethosome and control (Tf: 0.24) in 24 h. Conclusion: Ethosomes with a 30% ethanolic concentration were slightly more efficient in targeting HFs for dutasteride delivery. Full article

Biomimetic peptides represent a growing class of active ingredients in modern cosmeceuticals, designed to mimic the function of the naturally occurring peptides involved in skin homeostasis, repair, and regeneration. Among them, acetyl hexapeptide-8 (AH-8), often referred to as a “botox-like” peptide, has received considerable attention for its potential to dynamically reduce wrinkles through the modulation of neuromuscular activity. AH-8 is widely used in topical formulations intended for anti-aging effects, scar treatment, and skin rejuvenation. This review provides a comprehensive overview of the structure and proposed mechanisms of action of AH-8, with particular focus on its efficacy and skin penetration properties. Due to its hydrophilic nature and relatively large molecular size, AH-8 faces limited permeability through the lipophilic stratum corneum, making effective dermal delivery challenging. Formulation strategies such as oil-in-water (O/W) and multiple water-in-oil-in-water (W/O/W) emulsions have been explored to enhance its delivery, but the ability of AH-8 to reach neuromuscular junctions remains uncertain. Preclinical and clinical studies indicate that AH-8 may reduce wrinkle depth, improve skin elasticity, and enhance hydration. However, the precise biological mechanisms underlying these effects—particularly the peptide’s ability to inhibit muscle contraction when applied topically—remain incompletely understood. In some studies, AH-8 has also shown beneficial effects in scar remodeling and sebum regulation. Despite promising cosmetic outcomes, AH-8’s low skin penetration limits its bioavailability and therapeutic potential. This review emphasizes the need for further research on formulation science and delivery systems, which are essential for optimizing the effectiveness of peptide-based cosmeceuticals and validating their use as non-invasive alternatives to injectable treatments. Full article

Background/Objectives: Acne vulgaris is a chronic skin infection characterized by high sebum secretion, keratosis around hair follicles, inflammation, and imbalance in androgen levels. Acne vulgaris causes permanent scars or skin pigmentation in cases of improper treatment. Oral or topical isotretinoin, contraceptives, and antibiotics are used to treat acne. Minocycline is one of the widely used tetracyclines for this purpose; it inhibits the synthesis of proteins in bacterial ribosomes. Commonly, minocycline is prescribed daily for several months for acne vulgaris. Systemic minocycline is highly distributed into body fluids, and it is associated with several side effects and antibiotic resistance. Additionally, minocycline is highly metabolized in the liver, leading to reduced bioavailability upon systemic delivery. This study aims to develop and characterize minocycline nanocrystals for targeted skin delivery and evaluate their antimicrobial efficacy in treating acne vulgaris. Methods: Minocycline nanocrystals were synthesized using milling or solvent evaporation techniques. Nanocrystals were characterized in terms of particle size, particle distribution index (PDI), zeta potential, and morphology. The antibacterial efficacy against Propionibacterium acne, Staphylococcus aureus, and Staphylococcus epidermidis was evaluated using a minimum inhibitory concentration assay (MIC) and agar well diffusion test in comparison to coarse minocycline. Results: Minocycline nanocrystals had a particle size of 147.4 ± 7.8 nm and 0.27 ± 0.017 of PDI. The nanocrystals exhibited a loading efficiency of 86.19 ± 16.7%. Antimicrobial testing showed no significant difference in activity between minocycline and its nanoparticle formulation. In terms of skin deposition, the nanocrystals were able to deliver minocycline topically to rat skin significantly more than free minocycline. The nanocrystal solution deposited 554.56 ± 24.13 μg of minocycline into rat skin, whereas free minocycline solution deposited 373.99 ± 23.32 μg. Conclusions: Minocycline nanocrystals represent a promising strategy for targeted skin delivery in the treatment of acne vulgaris, potentially reducing systemic side effects and antibiotic resistance and improving patient outcomes. Full article

Acne vulgaris is one of the most common dermatological diseases and has a complex etiology. Despite the wide range of available therapeutic options, modern and effective solutions are still being sought, particularly in the area of topical therapy. The aim of this study was to develop hydrogel formulations that provide stability for the antibiotics they contain—tetracycline or chlortetracycline enriched with azeloglycine—the latter an ingredient supporting acne-prone skin care. The physicochemical parameters, stability, and antimicrobial activity of the obtained formulations were analyzed. HPLC analysis showed that tetracycline exhibited greater stability than chlortetracycline, especially in mildly acidic and neutral environments. The addition of azeloglycine improved the rheological properties of the hydrogels, reduced tetracycline degradation under alkaline conditions, and enhanced the penetration of active ingredients into the model sebum. All tested formulations demonstrated antimicrobial activity against Staphylococcus aureus. In the artificial sebum biofilm model, hydrogels containing azeloglycine more effectively reduced staphylococcal biofilm mass. No formulations showed toxicity towards Galleria mellonella larvae. The results indicate the potential usefulness of the developed hydrogels as modern multifunctional formulations for topical acne treatment. Hydrogel formulations containing tetracycline and azeloglycine may represent a promising future anti-acne preparation exhibiting synergistic antibacterial, anti-inflammatory, and sebum-cleansing effects. Full article

Cumulative exposure to UV radiation can lead to harmful effects such as skin burns, photoaging, and skin cancer, thus highlighting the importance of using photoprotective formulations. Many sunscreens are vegan and have antioxidant substances to ensure additional photochemoprotective action. We evaluated biophysical, rheological, and sensorial parameters of Face Care Facial Moisturizing Cream^® (P1) and a vegan formulation (P2) by in vitro and in vivo tests. Sun Protection Factor (SPF) was evaluated by Mansur method. Biophysical parameters were analyzed: sebum content, hydration level, transepidermal water loss, erythema and melanin level, skin color, and skin pH. The acceptance profile of the formulations was determined using a 9-point hedonic scale and a 5-point purchase intention test. The SPF values of P1 and P2 obtained by in vitro tests were 25.21 and 12.10, respectively. They also exhibited pseudoplastic and thixotropic behavior, which could contribute to better spreadability and form a protective film. Biometric tests showed an increase in hydration and skin sebum, decreased erythema, and maintenance of skin pH after application of both formulations. The comparison of a commercialized product and a vegan test version showed similar rheological and great acceptance profiles. Therefore, the vegan formulation is a good alternative to reach a different market. Full article

Background: Dissolvable Microneedle Patches (DMP) have emerged as a promising approach for improved topical delivery of skincare agents with dermatological values (dermo-cosmetics), effectively addressing the various skin concerns. These patches enable minimally invasive penetration of the skin’s outer layer, facilitating efficient transdermal delivery of actives by overcoming skin barrier for successful outcomes. Objectives: The aim of this work was to assess the efficacy and safety of hyaluronic acid-based microneedle patches (HA-MNP) with agents for the managements of an inflammatory disorder of acne. A particular focus was on helping individuals with moderate inflammatory acne. Methods: A single-center clinical trial was conducted over a period of four weeks on acne patients. Measurable skin properties, including sebum content, redness, and severity of inflammation, were evaluated to gauge the overall usefulness of the MN patches. Results: The application of the patches resulted in a significant decrease in sebum content, with reductions of −4.9% and −36.8% observed after two and four weeks of use, respectively. The redness of localized acne lesions also showed a marked decline, with reductions of −47.2% and −65.5% observed after two and four weeks of use, respectively. Additionally, the severity of inflammatory signs in acne lesions showed significant improvements, with reductions of −68.8% and −83.3% observed for the application periods. The patches utilized in this investigation exhibited highly encouraging results, displaying a notable synergistic effect in the context of combating acne without adverse effects. Conclusions: The patches have the potential to be broadly applied as a modular and adaptable approach for therapeutic delivery of actives for various skin diseases and concerns. Full article

The sebaceous gland (SG) is an integral part of the pilosebaceous unit and is a very active and dynamic organ that contributes significantly to the maintenance of skin homeostasis. In addition to its primary role in sebum production, the SG is involved in the maintenance of skin barrier function, local endocrine/neuroendocrine function, the innate immune response, and the regulation of skin bacterial colonization. Structural and functional alterations of SGs leading to the dysregulation of sebum production/composition and immune response may contribute to the pathogenesis of inflammatory dermatoses. This review summarises the current knowledge on the contribution of SGs to the pathogenesis of common inflammatory skin diseases. These findings are crucial for the development of more effective therapeutic strategies for the treatment of inflammatory dermatoses. Full article

Background: Scald burns pose significant morbidity, and effective topical treatments remain a clinical priority. Burn injuries pose a significant clinical challenge due to the prolonged inflammation and high infection risk. Traditional treatments focus on moisture retention and infection prevention, but biocompatible formulations such as hydrogels and oleogels offer advantages. Hydrogels hydrate, cool, and promote epidermal regeneration, while oleogels form a lipid barrier that enhances the absorption of lipophilic bioactive compounds. There is an increasing demand for novel topical alternatives that can effectively improve wound healing by modulating the inflammatory cascade, accelerating epithelial and dermal regeneration, and restoring barrier function. Objective: This study aimed to determine the most effective plant-based topical formulations for enhancing second-degree scald burn wound healing. Methods: Utilizing a standardized rat model, we compared 21 distinct topical formulations, consisting of oleogel and hydrogel bases enriched with extracts from Boswellia serrata (frankincense), Ocimum basilicum (basil), Sambucus nigra flower (elderflower), and Galium verum (lady’s bedstraw). Second-degree burns were uniformly induced in 24 Wistar rats using boiling water (100 °C for 8 s) using the RAPID-3D device, a validated 3D-printed tool that ensures reproducible burns through controlled exposure to boiling water. Post-burn, rats were divided into three equal subgroups, and topical formulations were applied daily. Wound healing efficacy was evaluated through wound surface area measurements, transepidermal water loss (TEWL), skin hydration, sebum production, pigmentation, inflammation (erythema), skin perfusion, and histological parameters at multiple timepoints (days 1, 4, 9, 14, and 21 post-burn induction). Results: Statistical analyses indicated significant advantages of oleogel-based formulations over hydrogel-based formulations. Specifically, formulations containing Boswellia serrata and Ocimum basilicum extracts significantly reduced wound size and inflammation, improved skin hydration, and decreased melanin production by days 9 and 21 (p < 0.05). Conclusions: These findings underscore the potential clinical value of oleogel-based topical preparations containing specific plant extracts for improving scald burn wound healing outcomes, warranting further clinical evaluation. 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

A systematic study on the mechanisms of cleansing artificial skin by solutions of widely used in personal care surfactants disodium laureth sulfosuccinate (DSLSS), sodium laureth sulfate (SLES), sodium dodecyl sulfate (SDS), dodecyl trimethyl ammonium bromide (DTAB), and coco glucoside (CG), is presented. The systematic characterization of soil removal from artificial skin revealed two primary cleansing mechanisms: emulsification and roll-up. Emulsification occurs in systems with very low interfacial tension, such as sebum in SLES solutions, while dimethicone soil was only removed by roll-up. The roll-up effectiveness depends on the surfactant’s interfacial activity and its adsorption on the soiled surface. Thus, the strong adsorption of DTAB on the skin leads to dimethicone roll-up at a relatively high interfacial tension of 11 mN/m. The anionic and nonionic surfactants adsorbed less at the artificial skin surface, and the oil/water interfacial tension value lowering below 5 mN/m is necessary for the roll-up to occur. Nonionic CG removed dimethicone at a lower concentration than ionic surfactants. Combining CG with ionic surfactants improved cleaning at lower total concentrations. Surfactant mixtures are used to formulate simple cleansing formulations, whose performance is also investigated by the developed in vitro approach. The results obtained allow for a good rating of the formulations, which correlates well with the performance of the surfactant mixtures and their interfacial activity. Full article

Acne vulgaris is a dermatological condition characterized by the hyperkeratinization of sebaceous follicles, which can further lead to post-inflammatory hyperpigmentation. Considering the intricate pathophysiology of acne, it is essential to develop novel topical therapies that are capable of targeting multiple underlying mechanisms of acne. The objective of this study was to study the effect of products containing retinol, niacinamide, ceramides, and dipotassium glycyrriszinate on acne-related markers. A total of 43 women with acne skin (including sensitive skin) were enrolled. To evaluate the effect of test products on acne-related indicators following 4 weeks of use, this study combined clinical assessments of skin condition (acne lesion counts), instrumental assessments (skin gloss), and photo tracking using VISIA-CR and Primos CR systems, which encompass metrics such as a*, ITA°, skin area (%) covered by sebum spots, and the presence of sebum spots. Adverse reactions were also assessed. After 4 weeks of treatment, significant reductions were observed in both the inflammatory acne lesion count and non-inflammatory acne lesion count, while there was also a significant decrease in skin redness a* and skin area (%) covered by sebum spots and a significant increase in skin brightness ITA° and gloss. No adverse events occurred during the entire testing process. In summary, the daily application of products containing retinol, niacinamide, and ceramides not only improves acne-related symptoms but also alleviates post-inflammatory hyperpigmentation caused by acne, which suggests that such products have the potential to meet the dual needs of brightening and acne care. Full article

This study aimed to evaluate the daily use safety and instrumental efficacy for sebum control of a cosmetic elastomer-type formulation containing the vegetable seed oils of Plukenetia huayllabambana, Physalis peruviana L., and Bertholletia excelsa. Assessments were conducted using a skin irritation index and the Sebumeter^® SM 815 from Courage + Khazaka Electronics GmbH, Cologne, Germany. Sebum control efficacy was determined in three groups of volunteers seated in a room at a temperature of 26 ± 1 °C. The forehead area was divided into two sections: one received the cosmetic elastomer while the other area received no product. The elastomer significantly reduced sebum levels in all three groups at 2, 4, and 5 h (p < 0.05) compared to the untreated area, and the third group exhibited higher sebum reductions, with 43.48%, 52.43%, and 43.95%, respectively. In conclusion, the dermatologically tested and safe cosmetic product contains a balanced combination of active ingredients that effectively control sebum levels, resulting in visibly oil-free skin. Full article