International Journal of Cosmetic Science最新文献

{"title":"A novel approach to target skin photodamage: Topical application of salt inducible kinase inhibitors.","authors":"Inbal Rachmin, Béatrice Le Varlet, Claire Regazzetti, Thierry Passeron, Jinhua Wang, David E Fisher, Philippe Schaison, Braham Shroot","doi":"10.1111/ics.70003","DOIUrl":"https://doi.org/10.1111/ics.70003","url":null,"abstract":"<p><strong>Background: </strong>Ultraviolet (UV) radiation accelerates skin damage and photoageing, leading to visible signs such as wrinkles, loss of elasticity and uneven pigmentation. UV radiation causes direct DNA damage, primarily through the formation of cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts (6-4PPs), which can lead to mutations and cellular dysfunction if not repaired. While natural defence mechanisms like melanin production and DNA repair pathways mitigate this damage, prolonged or excessive UV exposure can overwhelm these defences, resulting in cumulative skin damage. The melanocortin 1 receptor (MC1R) plays a key role in melanogenesis and also appears to play a role in DNA repair. Salt-inducible kinases (SIKs), critical enzymes in the MC1R pathway, are known to influence melanin production, but their role in DNA repair and photodamage remains unclear.</p><p><strong>Objective: </strong>This study investigated the role of SIK in DNA repair and photodamage, focusing on two novel cosmetic ingredients, SIK inhibitors, coded SLT-008 and SLT-001.</p><p><strong>Methods: </strong>The inhibitory effects of the ingredients on SIK activity were measured using biochemical and cellular assays. Their safety profiles were evaluated through in vitro studies and clinical trials. To analyse their impact on UV-B-induced DNA damage and repair, both inhibitors were topically applied to skin extracts in an ex vivo model. Finally, clinical studies were conducted in healthy volunteers irradiated with UV-R. Efficacy was determined by measuring CPD levels, matrix metalloproteinase-1 (MMP-1), expression and erythema formation following UV exposure.</p><p><strong>Results: </strong>Both ingredients effectively inhibited SIK activity and demonstrated good safety profiles. Ex vivo experiments revealed that immediate post-UV-B application of both ingredients significantly reduced UV-B-induced DNA damage, as shown by decreased CPDs, and promoted tissue repair. Additionally, both inhibitors suppressed MMP-1 expression, an enzyme that plays a key role in the breakdown of collagen, thereby accelerating photoageing. These findings were confirmed in the clinical study, which demonstrated that topically applied SLT-001 enhanced DNA repair, reduced MMP-1 expression and decreased erythema formation.</p><p><strong>Conclusion: </strong>Here we described the comprehensive role of SIK inhibition in DNA and dermal repair. This highlights its crucial role in protecting skin against UV-induced photodamage and offering broad protection against actinic ageing.</p>","PeriodicalId":13936,"journal":{"name":"International Journal of Cosmetic Science","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144707420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of single hair fibre tensile measurements to create an industry-standard heat damage scale for hair.","authors":"Neil Shaw, Michela Buscemi, Dajana Gubala, Juliet Scott-Pritchard, Charles Stanton-Stock, Peter Bailey","doi":"10.1111/ics.13084","DOIUrl":"https://doi.org/10.1111/ics.13084","url":null,"abstract":"<p><p>The use of heat styling appliances is a rapidly growing segment within the hair care market. However, despite significant levels of academic investigation into the impact of high temperature on the structure and mechanical properties of the hair fibre, the industry does not yet have a standardized method of heat damage measurement to enable consumers and independent evaluation laboratories to objectively compare the performance of different heat styling tools. We discuss the available experimental methods to support such a standardized method and conclude that the well-established approach of measuring single-fibre tensile strength provides the best option. We then explore the sensitivity to heat damage of the various wet and dry single-fibre tensile parameters in order to identify the optimal combination for inclusion in our hair damage metric. Using the selected combination of 8 different wet single-fibre tensile strength parameters, we now propose a robust, reproducible and consumer-relevant 6-point heat damage scale. We demonstrate the relevance of the new damage scale to a range of on-market heated hair straighteners and explore the human perception of hair treated with heated straighteners delivering different damage levels according to the new scale. Based on this, we show a good correlation between the technical damage scale and the human perception of damage on hair tresses.</p>","PeriodicalId":13936,"journal":{"name":"International Journal of Cosmetic Science","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144707421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Galactomyces ferment filtrate upregulates anchoring junctions and stabilizes actin to maintain the Young's modulus of skin cells in vitro.","authors":"Steph Crabtree, Bradley B Jarrold, Olivia Kent, Matthew C Ehrman, Timothy J Hawkins, Viktor Korolchuk, Camila Pereira Braga, John M Snowball, Makio Tamura, Tomohiro Hakozaki, Akira Matsubara, John E Oblong, Max Brown","doi":"10.1111/ics.70009","DOIUrl":"https://doi.org/10.1111/ics.70009","url":null,"abstract":"<p><strong>Objective: </strong>Skin is exposed to multiple external factors such as solar radiation and environmental oxidative stressors. Ageing and the accumulation of stress damage lead to reduced skin health and loss of skin firmness, which contribute to wrinkling and sagging. We investigated if Galactomyces ferment filtrate (GFF) could modulate skin cell mechanical properties through changes to the actin cytoskeleton and anchoring junctions.</p><p><strong>Methods: </strong>Proteomic analysis was performed to identify age-associated changes in cellular components in skin biopsies and GFF-mediated changes in full thickness 3D skin equivalent models. Nanoindentation was used to measure the Young's modulus (resistance to elastic deformation) of keratinocyte cells under Latrunculin B (LatB)-induced destabilization of the actin cytoskeleton. Immunofluorescence and confocal microscopy were performed on skin equivalents to validate the GFF-induced changes observed in proteomic analysis and identify expression profiles of key structural proteins within the skin.</p><p><strong>Results: </strong>Aged skin had decreased expression of internal cellular components 'actin cytoskeleton' and 'focal adhesion'. Destabilization of actin cytoskeleton by LatB significantly reduced the Young's modulus of keratinocyte cells. Pre-treatment of keratinocytes with GFF was able to prevent LatB-induced decline of skin cell mechanical properties. Proteomic analysis of full thickness 3D skin equivalent models revealed that GFF increased the expression of 'actin cytoskeleton' and 'anchoring junctions', especially the actin-binding focal adhesion proteins. Immunofluorescence staining confirmed that GFF upregulated expression of the actin stabilizer, calponin 2 and integrin α2 in basal keratinocytes. GFF increased integrin localisation to the dermal-epidermal junction (DEJ) and colocalised with collagen IV in vitro, suggesting increased linkage between the epidermis and dermis.</p><p><strong>Conclusion: </strong>Our data establish the actin cytoskeleton and anchoring junctions which bind it as important cellular structures which decline with age. We also identified that the cellular structures are required for the maintenance of keratinocyte Young's modulus, which could be an important property impacting skin firmness. Furthermore, we have identified that GFF promotes actin stability and builds a rigid holding structure of the anchoring junctions to increase cell-cell and epidermis-dermis anchoring in skin equivalent models. Therefore, GFF has the potential to help maintain and restore skin firmness in young and old skin, respectively.</p>","PeriodicalId":13936,"journal":{"name":"International Journal of Cosmetic Science","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144707422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photostability and phototoxicity studies of a promising UVA filter for sunscreens: 1-(2-hydroxyphenyl)-3-(4-methoxyphenyl)-1,3-propanedione.","authors":"Yanina Susana Minaberry, Gabriel Sagrera, Mora Reneé García, María Laura Gutiérrez, Federico Eugenio Svarc","doi":"10.1111/ics.70012","DOIUrl":"https://doi.org/10.1111/ics.70012","url":null,"abstract":"<p><p>A few years ago, the 2-hydroxy-4´-methoxy dibenzoylmethane (DBM11) molecule was synthesized and studied as a replacement for avobenzone (AVB, butyl methoxydibenzoylmethane) because of the latter's instability under UVA radiation. These studies, conducted in absolute ethanol with an estimated UV irradiance of 8,56 mW/cm², demonstrated almost zero decomposition of DBM11. Thus, it is a promising candidate for use as a UVA chemical filter. However, further studies must be conducted to verify its photostability once formulated into an emulsion and to establish its toxicological profile. The first aim of this work was to scale up the synthesis of DBM11 to allow its formulation into an emulsion, which is required for the evaluation of its photostability under standardized UV irradiation conditions (close to ISO 24443), as required for sunscreen testing in the cosmetic industry. Additionally, in vitro phototoxicity assessments were conducted, with slight modifications to improve reproducibility, in accordance with OECD guidelines. These results demonstrate that DBM11 exhibits promising photostability and a favourable toxicological profile, making it a potential candidate for use as a UVA filter.</p>","PeriodicalId":13936,"journal":{"name":"International Journal of Cosmetic Science","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144707423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A colloidal oat-containing baby wash is gentle and effective for atopic-prone skin.","authors":"M Catherine Mack, Gabriella John, Diana Friscia, Christine Perna, Denise Bion, Melody Ailsworth, Kappa Peddy, Neena K Tierney","doi":"10.1111/ics.70010","DOIUrl":"https://doi.org/10.1111/ics.70010","url":null,"abstract":"<p><strong>Objective: </strong>Despite accumulating data supporting the effectiveness of colloidal oatmeal-based moisturizers in improving mild-to-moderate atopic dermatitis (AD), evidence in paediatric populations is limited. This study evaluated the tolerability and effectiveness of a colloidal oatmeal-containing baby wash formulation in babies prone to AD, based on clinical and parental assessments.</p><p><strong>Methods: </strong>In this 4-week, single-centre, nonrandomized study of babies (3-36 months) prone to AD (per an AD-prone skin recruiting questionnaire developed in-house), parents/legal guardians used the baby wash on their babies ≥3 times per week (no more than once daily), each bath lasting ≤20 min. The overall skin condition (scored from 0/excellent to 3/poor) and cutaneous tolerance scoring of dryness, redness/erythema, rash/irritation and tactile roughness on the baby's face, arms, legs and torso (each scored from 0/none to 3/severe) were assessed clinically at baseline, Week 1 and Week 4. Cutaneous tolerance scoring of burning/stinging and itching on those body sites was evaluated by the parent per the latter scale at all visits. At study end, the parental questionnaire evaluated the level of agreement/disagreement with statements regarding the baby wash. Safety measures included adverse events and changes in health (per the parents or clinicians).</p><p><strong>Results: </strong>Of 29 infant-parent pairs enrolled, 24 (82.8%) completed the study. All 24 babies were White/Caucasian; 13 (54.2%) were male. The overall skin condition mean score showed no statistically significant change from baseline (0.54) at Weeks 1 (0.33) and 4 (0.29). Per the investigator-rated cutaneous tolerance scores, >87% of body sites exhibited no dryness, redness/erythema, rash/irritation or tactile roughness at Week 4. For each parameter, significant improvements from baseline were observed at Week 4 for the combined skin sites (p < 0.05). Per the parent-rated cutaneous tolerance scores, nearly all sites had no burning/stinging or itching at Week 4. Itching for the combined sites demonstrated significant improvements from baseline at Week 4 (p < 0.05). The parental questionnaire revealed statistically significantly more favourable experiences with the baby wash than unfavourable experiences. Four babies experienced five mild, treatment-unrelated adverse events.</p><p><strong>Conclusion: </strong>The study findings indicate that the colloidal oatmeal-containing baby wash was well tolerated and effective when used in babies with AD-prone skin.</p>","PeriodicalId":13936,"journal":{"name":"International Journal of Cosmetic Science","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144707419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PEG-23 glyceryl distearate, a multifunctional skin-supporting material, upregulates the expression of factors associated with epidermal barrier and hydration.","authors":"Tatsuro Miyoshi, Brian C Keller, Sui Nakagawa, Takashi Ashino, Satoshi Numazawa","doi":"10.1111/ics.70005","DOIUrl":"https://doi.org/10.1111/ics.70005","url":null,"abstract":"<p><strong>Objective: </strong>As the outermost organ of the human body, the skin plays a critical role in protecting against external agents and oxidative stress, as well as in preventing excessive water loss. Among its layers, the stratum corneum of the epidermis is central to both barrier function and moisture retention, with its structural integrity significantly influencing skin health and appearance. Polyethylene glycol-23 glyceryl distearate (GDS-23) can form niosomes, liposome-like structures with multiple layers and serve as a carrier in drug delivery systems (DDS). We previously reported that GDS-23 exerts multiple biological effects, suppressing inflammation and enhancing the endogenous antioxidant system via Nrf2 activation through phosphorylation of the autophagy adaptor protein p62. In this study, we investigated the effects of GDS-23 on epidermal barrier function and moisture retention using normal human epidermal keratinocytes (NHEKs) and a three-dimensional (3D) epidermal model, mimicking human skin structure.</p><p><strong>Methods: </strong>NHEKs and the 3D epidermal model were treated with GDS-23. Gene expression in NHEKs was analysed using real-time polymerase chain reaction, while the levels of epidermal barrier- and moisture retention-related factors in the 3D model were evaluated using immunofluorescence staining.</p><p><strong>Results: </strong>Treatment with GDS-23 upregulated the mRNA expression of genes involved in stratum cornea formation (filaggrin and loricrin), moisture retention (aquaporin 3 and hyaluronan synthase 3) and intercellular lipid synthesis (ceramide synthase, sulfotransferase 2B1 and peroxisome proliferator-activated receptor α) in NHEKs. Additionally, treatment with K67, which inhibits p62 phosphorylation and thereby suppresses Nrf2 activation via a non-canonical mechanism, suppressed the GDS-23-induced expression of filaggrin, loricrin, ceramide synthase, sulfotransferase 2B1 and aquaporin 3. In the 3D epidermal model, GDS-23 treatment upregulated the expression of Nrf2, downstream antioxidant factors and proteins involved in stratum corneum formation and moisture regulation. Mechanistically, GDS-23 enhanced endogenous antioxidant function and modulated the expression of molecular markers associated with epidermal barrier and moisture retention, thereby potentially contributing to skin homeostasis.</p><p><strong>Conclusion: </strong>As GDS-23 contributes to the maintenance of skin homeostasis, it is expected to have future applications in the cosmetic field and in the treatment of skin disorders. Overall, GDS-23 holds promise as a \"multifunctional DDS material\" that promotes skin health.</p>","PeriodicalId":13936,"journal":{"name":"International Journal of Cosmetic Science","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144600332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bioactivity and physicochemical characterization of Centella asiatica and Marigold extract serums: Antioxidant, anti-inflammatory, anti-tyrosinase and skin barrier function insights.","authors":"Rizos Evangelos Bikiaris, Magdalena Paczkowska-Walendowska, Ioanna Koumentakou, Argyri Niti, Judyta Cielecka-Piontek, George Z Kyzas","doi":"10.1111/ics.70006","DOIUrl":"https://doi.org/10.1111/ics.70006","url":null,"abstract":"<p><p>Centella asiatica extract (CAE) and Marigold extract (ME) have been renowned for centuries in traditional medicine, particularly in Asia, for their wound-healing, anti-inflammatory and skin-regenerative properties. This study presents the formulation and comprehensive evaluation of serums enhanced with these extracts, aiming to harness their bioactive properties for skin health. Serums were selected over creams due to their lightweight, water-based nature, which ensures faster absorption and enhanced skin penetration of active ingredients. The serums, developed in varying concentrations (0.2%, 0.5% and 1.0%), were assessed for physicochemical properties, stability, bioactivity and skin barrier enhancement. Stability tests confirmed the serums' robustness, maintaining consistent pH (5.0-6.5), viscosity and organoleptic properties over 60 days. The MTT assay revealed that both extracts were non-cytotoxic, maintaining cell viability above 100%, with formulations containing CAE, demonstrating a concentration-dependent proliferative effect, reaching nearly 120%. Antibacterial evaluation using the agar well diffusion assay showed that both extracts exhibited considerable activity, with CAE achieving greater inhibition zones, particularly against S. aureus. Antioxidant, anti-inflammatory and anti-tyrosinase activities confirmed the strong bioactive potential of both extracts in combating oxidative stress, reducing inflammation, and regulating pigmentation. Skin barrier and permeability studies demonstrated the serums' ability to improve barrier integrity and facilitate active compound delivery. These findings demonstrate the potential of Centella asiatica and Marigold extracts for multifunctional skincare formulations, combining regeneration, hydration, antioxidant and antibacterial benefits.</p>","PeriodicalId":13936,"journal":{"name":"International Journal of Cosmetic Science","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144600331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photoprotective efficacy of dibenzalacetone in sunscreen formulations: Physicochemical properties, synthesis, characterization, potential applications in sunscreen and biological activities.","authors":"Khaled E Abuelella, Saadalla Nady Gaid, Mahmoud Alaaeldin Khattab, Kareem O Rashwan, Nermin M Sheta","doi":"10.1111/ics.70002","DOIUrl":"https://doi.org/10.1111/ics.70002","url":null,"abstract":"<p><p>Sunscreens reduce the harmful effects of ultraviolet radiation (UVR) by reflecting, absorbing or scattering photons. UVR comprises ultraviolet-B (UVB), which plays a major role in sunburn and the development of skin cancers, and ultraviolet-A (UVA), which contributes to photoaging and skin damage. The application of sunscreen is among the most effective approaches to mitigating UV-induced damage. As a topical photoprotective agent, it can be classified as either inorganic (physical blockers) or organic (chemical absorbers). Physical sunscreens are particularly beneficial for people who are hypersensitive to UVA and visible light, such as those who have photosensitising diseases. Chemical sunscreens that selectively absorb UVB and/or UVA, include cinnamates, benzophenones, benzimidazoles and dibenzalacetone (DBA). DBA is a synthetic compound with potent UV-absorbing properties, making it an important component in sunscreen formulations for effective skin protection. This review provides a comprehensive analysis of DBA, focusing on its physicochemical properties, conventional synthesis methods and structural characterization using UV-Visible absorption spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, Gas Chromatography-Mass Spectrometry (GC-MS) and Nuclear Magnetic Resonance (NMR) spectroscopy. Furthermore, its potential applications in sunscreen formulations and other biological activities are critically investigated.</p>","PeriodicalId":13936,"journal":{"name":"International Journal of Cosmetic Science","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144600333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The variability of in vivo sunscreen sun protection factor values","authors":"Curtis Cole,&nbsp;Bertrand Colson,&nbsp;Steffen Uhlig","doi":"10.1111/ics.70000","DOIUrl":"10.1111/ics.70000","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>Determination of the sunburn protection provided by a sunscreen product is required globally for sales of these products. Over the past 80 years, many aspects of determining the protection ‘factor’ have evolved and been modified, with varying levels of impact on the sunburn protection factor (SPF) value. In order to compare new non-invasive and in vitro methods against traditional SPF test protocols, a large, multi-center clinical trial was conducted to establish the level of equivalence of these new methods with the current codified testing standard ISO24444 ([1]: Cosmetics – sun protection methods – in vivo determination of the sun protection factor (SPF), 2019). This report reports the variability found in the in vivo determination of SPF values.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Thirty-two products of varying levels of sunburn and UVA protection, in a variety of formulation vehicles and ultraviolet (UV) filter combinations and concentrations, were coded and sent to pre-qualified in vivo SPF testing laboratories. The products were divided into eight product groups (four products per product group). For each product group, samples were sent to four laboratories (across product groups, a total of 12 laboratories participated). Precision and trueness estimates were calculated separately for each product group. ‘Expected’ SPF values were not provided to the test laboratories. However, laboratories were informed as to whether the ‘true’ SPF was less than or greater than 25.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Interlaboratory variability for samples was proportional to the SPF of the products, with high SPF products having higher variability. Intra-laboratory variability (repeatability) was much lower than the interlaboratory variability.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study highlights the fact that the interlaboratory variability of SPF results is considerable and is likely greater than expected by the public and regulatory bodies.</p>\u0000 </section>\u0000 </div>","PeriodicalId":13936,"journal":{"name":"International Journal of Cosmetic Science","volume":"47 S1","pages":"25-36"},"PeriodicalIF":2.5,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ics.70000","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144600334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scattering as part of the protection afforded by nanoparticulate filters - An example with tris-biphenyl triazine.","authors":"Myriam Sohn, Axelle Staudt, Katja Quass, Bernd Herzog","doi":"10.1111/ics.70001","DOIUrl":"https://doi.org/10.1111/ics.70001","url":null,"abstract":"<p><strong>Objective: </strong>Tris-biphenyl triazine (TBPT) is an organic nanoparticulate UV filter for use in sunscreens. Thanks to its chemical structure and particulate properties, the effectiveness of TBPT is associated with both absorption and scattering processes. In our study, we evaluated how much of the UV protection of TBPT is linked to scattering, including forward and backward scattering.</p><p><strong>Methods: </strong>We employed a two steps approach. At first, we reproduced an earlier experimental design based on transmittance measurements of an aqueous dispersion of TBPT in cuvettes using a UV/vis-spectrometer with and without integrating sphere. Since the dispersion of TBPT is intended to be used in a finished sunscreen product, in a second phase, the supplied TBPT dispersion was added to a formulation, which was applied on a substrate plate to mimic the real use scenario. In this experimental setup, the scattering contribution was evaluated using transmittance measurements with an integrating sphere, both with closed and with open backward window.</p><p><strong>Results: </strong>The two approaches produced the same results for the experiments conducted in cuvettes and on plates. The percentage of scattering contribution is dependent on the wavelength, which is connected to the absorbance profile of TBPT. In the UVB range the efficacy of TBPT is primarily provided by absorption with little scattering. In the UVAI range (340-400 nm), where TBPT is not absorbing the protection is completely attributed to scattering. Also, the use concentration of TBPT was shown to impact the percentage of scattering. A decrease of the scattering effect is observed when the concentration of TBPT exceeds 3% (w). This can be attributed to the fact that in concentrated systems absorption becomes the main effect as the likelihood of scattered light hitting and being absorbed by another TBPT molecule increases due to the closer proximity of the molecules.</p><p><strong>Conclusion: </strong>This method can be used in the future to assess the scattering contribution of other particulate organic or inorganic UV filters or cosmetics particulate ingredients added in cosmetic formulations.</p>","PeriodicalId":13936,"journal":{"name":"International Journal of Cosmetic Science","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144608292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}