Daily Cosmetic Research Analysis

BACKGROUND: Conventional sunscreens can penetrate the skin, potentially causing irritation and raising safety concerns. This study introduces a novel sunscreen technology designed to prevent skin penetration while maintaining high efficacy. AIMS: To evaluate the safety, efficacy, and skin penetration profile of an innovative sunscreen that microencapsulated UV filters (octocrylene and avobenzone) within a silk peptide modified polysilicone-14, and to compare it to a conventional, nonencapsulated formulation. METHODS: The innovative formulation was assessed using a Human Repeated Insult Patch Test (HRIPT) to determine irritation and allergenic potential. Sun protection efficacy was measured in vivo (SPF, PFA). Skin penetration was evaluated using in vitro Franz cell assays with a Strat-M membrane and in vivo via Raman spectroscopy, which measured penetration into the stratum corneum and epidermis over time. Sensory assessment and tolerability were also conducted on volunteers with sensitive skin. RESULTS: The HRIPT confirmed the innovative sunscreen was nonirritating and nonallergenic. It demonstrated equivalent sun protection efficacy to the conventional sunscreen, with an SPF of ~30 and PFA of ~10. Crucially, the Franz cell assay showed zero (0.00%) penetration of UV filters for 6 h. Raman spectroscopy confirmed no penetration into the stratum corneum for 4 h and no penetration into the epidermis for 8 h. The formulation was well-tolerated by sensitive skin volunteers. In contrast, the conventional sunscreen showed significant skin penetration and caused irritation. CONCLUSIONS: The innovative microencapsulation technology successfully creates a safe, non-skin-penetrating sunscreen with high UVA/UVB protection. This technology offers a superior safety profile, making it particularly suitable for populations with sensitive skin.

INTRODUCTION: It has been reported that pregnant women used more cosmetics daily than non-pregnant women. Phenoxyacetic acid is the main metabolite of phenoxyethanol, the most frequent preservative in cosmetics used in Europe, previously associated with reproductive effects (longer time to conception, endocrine disruptors in newborns and poorer verbal comprehension in children). In France, specialised platforms (PREVention ENvIronment Reproduction (PREVENIR)) in university hospital maternity wards are dedicated to evaluating environmental and occupational exposures in patients with pregnancy-related pathologies and supporting targeted prevention efforts. These platforms are composed of occupational health physicians, obstetrician-gynaecologists, midwives, occupational health nurses, and occupational health and environmental engineers. To assess the efficacy of these platforms, we developed a randomised clinical trial, the protocol for which is presented in this paper. The primary objective of the PREVENIR-G Study is to compare the change in urinary phenoxyacetic acid concentrations from baseline to 3 months postintervention between an intervention group and a control group. To date, the intervention has been integrated into routine care in certain facilities; however, its efficacy remains unproven. It is therefore essential to assess the relevance of this intervention, considering both its potential benefits and any adverse effects, such as increased stress or anxiety. METHODS AND ANALYSIS: This study is an unblinded, randomised clinical superiority trial with two parallel groups (intervention vs no intervention) in four university maternity hospitals in France. We will include 300 pregnant women (aged 18 years or older) who are under 24 weeks of gestation (150 per group) referred to the participating PREVENIR platforms for management. The intervention will consist of clinical prevention management through the PREVENIR platforms, involving a consultation with an environmental health expert for an assessment of environmental and occupational exposures. During the consultation, targeted prevention messages will be provided based on identified exposures. The no intervention comparator will be a waiting-list control group. At the inclusion visit, patients will receive urine collection vials for samples to be collected at baseline and again at 3 months. Urine samples will be collected twice in a single day, on three separate days, during the collection week at home. In the week following the urine collection period, only participants in the intervention group will engage with the PREVENIR platforms. The primary outcome will be the difference in the urinary phenoxyacetic acid concentration between baseline and 3 months postintervention, compared between the intervention and control groups. ETHICS AND DISSEMINATION: The study has been approved by the hospital ethics committee (CCP Ouest 2, no. 2023-A00941-44). All participants will provide written informed consent. Results will be shared through presentations and publications. TRIAL REGISTRATION NUMBER: NCT06642818.

BACKGROUND: Botulinum toxin type A (BoNT-A) is commonly used in neuromuscular disorders and cosmetic fields, but the detailed histological and subcellular changes in masticatory muscles, mainly in masseter, remain underexplored. METHODS: The literature review was conducted using the PubMed and Cochrane databases between January 2000 and September 2024. Studies of BoNT-A injection in masseters with available full- text and extractable data were included and were grouped depending on injected species. The sample size, dose of injection, follow-up duration, and detailed muscle changes were concluded. RESULTS: Fourteen articles were eligible for reviewing, among which 2 were conducted on humans, and 12 were conducted on animals including rats (n=5), mice (n=2), rabbits (n=3) and pigs (n=2). Morphological analysis showed muscle atrophy with variable recovery. Histological findings included decreased fiber diameter, disrupted arrangements, and shifts in myosin-heavy-chain fiber types. Immunohistochemistry indicated increased cell proliferation and nuclear centralization. Electrophysiological assessments demonstrated reduced EMG amplitudes and shorter signal durations, correlating with muscle size and bite force. Ion analysis revealed increased sodium, chloride and sulfur, and decreased potassium and phosphorus. CONCLUSION: BoNT-A injection causes dose-dependent denervation and dysfunction in masticatory muscles, with incomplete recovery over time. However, due to very limited human data, these findings should be interpreted cautiously, and strong clinical extrapolations are not justified. These findings provide valuable insights into the long-term effects of BoNT-A on muscle structure and function, highlighting the need for further research into the mechanisms underlying these changes and their clinical implications for both therapeutic and aesthetic applications. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .