Daily Cosmetic Research Analysis

Grouping of chemicals has been proposed as a strategy to speed up the screening and identification of potential substances of concern among the broad chemical universe under REACH. Such grouping is usually based on shared structural features and should only be used for the prioritization objectives. However, additional considerations (as well as structural similarity) are needed, e.g., mode of action, metabolic pathways, chemical reaction products and physicochemical properties, when regulatory management measures are considered (such as restriction, harmonized classification and labeling). Guidance documents from the European Chemicals Agency (ECHA) recommend considering toxicokinetic information to enhance the robustness of the grouping; however, examples of this approach are lacking. Therefore, this paper shares findings on chemical grouping based on ADME data generated for multiple esters of salicylic acid. These differ with respect to chain length and branching of the alcohol moiety of salicylic acid ester, resulting in a wide range of lipophilicity (LogP 0.21-10.88). Since LogP impacts skin absorption, as well as hydrolysis by carboxylesterases, the bioavailability and thus internal exposure to topically applied salicylate esters can vary considerably. Therefore, we collected skin absorption and metabolism data for 41 salicylates using in vitro testing and in silico models and combined the information to group them according to their potential systemic exposure to the major metabolite, salicylic acid. The results show that, despite a similar general chemical structure, their toxicokinetics vary considerably, indicating the need for better understanding of ADME properties to assess the internal exposure for sound risk assessment.

Traditional wound care preparations frequently face challenges such as complex care protocols, poor patient compliance, limited skin permeability, lack of aesthetics, and inconvenience, in addition to the risk of bacterial infection. We developed a spray film preparation containing nanocellulose and L-serine modified nanosilver, capable of rapidly forming a transparent film on the skin within minutes of application. The incorporation of nanocellulose imparted protective, moisturizing, and breathable properties to the film, allowing for easy removal after use. Moreover, our innovative application of L-serine as a precursor for synthesizing silver nanoparticles not only overcomed the limitations of current silver nanoparticle synthesis methods but also enhanced antibacterial efficacy by leveraging the inherent antimicrobial properties and bacterial targeting capability of L-serine. Specifically, the addition of nanocellulose to the spray film forming system enhanced air permeability and drug carrying capacity by creating a lightweight porous structure, while also ensuring the antimicrobial and anti-inflammatory efficacy of serine modified silver nanoparticles. Mice treated with spray film formulations containing nanocellulose and silver nanoparticles demonstrated superior wound healing, normalization of keratin thickness, increased hair follicle count, and reduced inflammatory markers. In conclusion, our study developed a spray film that integrated excellent antimicrobial properties with user convenience. This research presented innovative strategies for clinical wound care, antibacterial infection management, and post laser cosmetic treatment, with the potential to substantially enhance wound care in practical application.

Chlorogenic acid, a well-known antioxidant, has potential applications in health care, food, and cosmetic sectors. However, its low solubility hinders its application at the industrial scale. The primary goal of the present study was to increase the lipophilic property of chlorogenic acid through esterification using an ultrasonication approach and Novozym® 435 as the catalyst. The esterification was executed in two ways. In the first method, chlorogenic acid was converted to chlorogenic acid ester using octanol in a solvent-free reaction. Catalytic factors such as reaction time (12 h ∼ 36 h), enzyme dosage (10 ∼ 50 mg), and ultrasonication power (90 ∼ 150 W) were optimized using Box-Behnken design (BBD) while temperature (60 ℃) and molar ration (chlorogenic acid/octanol, 1:500) were kept constant. A maximum conversion rate of 95.3 % was achieved when the esterification was performed for 12 h at 120 W ultrasonication power and 50 mg enzyme dosage. Contrary to the first method, when esterification was done using caprylic acid in the presence of 2-methyl-2-butanol as a solvent, the conversion rate was relatively low. Despite optimization of factors including molar ratio, enzyme dosage, and reaction time, the highest conversion rate achieved was of only 36.8 %. Moreover, molecular docking results revealed that the lowest binding energy was between lipase and octanol. The finding of the study clearly stated that the esterification of chlorogenic acid was more effective in a solvent-free condition as compared to in the presence of solvent.