The safety and efficacy of raw cosmetic materials and products are important throughout the development and marketing process. National cosmetic regulations are becoming increasingly strict, especially in the requirement of scientific evidence to support efficacy claims. Therefore, reliable efficacy data will directly affect the development and sales of cosmetic products.
Traditional methods for evaluating the safety and efficacy of raw cosmetic materials often involve biochemical methods, animal models, in vitro cell models, in vitro animal replacements, and clinical evaluation. In addition, sensory evaluation and consumer surveys can provide different angles of data support for the efficacy of cosmetics.
Biochemistry and analytical chemistry are common laboratory methods and are simple to operate. By using basic chemical instruments and commonly used reagents, these methods detect and analyze some special indicators related to the safety and efficacy of ingredients. These methods generally belong to mature methods, including listed methods in classic literature, professional textbooks, and standards and regulations. While the technical requirements and instrument requirements are not high, precision, accuracy, linearity range, and experimental error should be carefully considered.
For example, through free radical scavenging experiments, oxidation substances react with substances that can easily be oxidized to form oxidized products. Then, certain ingredients are added to test their ability to scavenge free radicals and evaluate their antioxidant ability. Similar testing methods include oxygen free radical absorption ability, hydroxyl radical scavenging ability measurement, superoxide anion radical scavenging ability measurement, reduction capacity determination, and total antioxidant capacity testing. In addition to detecting free radicals, indicators such as ROS activity, superoxide dismutase, glutathione peroxidase, malondialdehyde, and catalase can reflect the antioxidative ability of the component being tested from different angles.
Under laboratory conditions in vitro, cells are cultured and incubated to simulate human physiological environments or specific conditions. The differences and changes in cell growth status, physiological indicators, and metabolic reactions before and after the addition of drugs or raw cosmetic materials are compared to evaluate whether the ingredient has a certain efficacy under safe concentration. According to the characteristics of cosmetics, cell biology methods often use human skin cell lines, such as epidermal keratinocytes, fibroblasts, melanocytes, epithelial cells, sebaceous gland cells, hair follicle cells, and some immune cells as in vitro cell evaluation model sources. Cells can be stimulated with H2O2 or LPS to establish a peroxide or inflammatory model, or irradiated with UV to establish a photodamage or photoaging model for evaluation and testing.
Zebrafish is a common classic model organism in cell biology research. The homology between zebrafish and human genes is as high as 87%, and it has a high similarity to humans in physiological function, immune system, and biological signal transduction pathways. Zebrafish has many advantages as a model organism, such as short growth cycle, small size, clear genetic background, and the ability to achieve high-throughput screening. Moreover, zebrafish embryos and young fish up to five days old comply with the international "3R" principle for the welfare of experimental animals in terms of ethical protection of experimental animals, making it an excellent drug screening model.
Currently developed in vitro testing methods, whether for safety testing or efficacy evaluation, can be used in the screening and preliminary verification of raw cosmetic materials and product development and provide theoretical support and data references for human clinical testing. Different dimensions of in vitro testing methods, combined with human clinical testing, sensory evaluation, and consumer surveys, among other different methods can jointly construct a scientific system for the safety and efficacy evaluation of raw cosmetic materials and products.
Raw cosmetic materials are not only the source and foundation of the entire lifecycle of cosmetics but also the main component of the product. In particular, active ingredients, as representatives of efficacy additives, endow cosmetics with diverse efficacies and characteristics. With the rapid development of the cosmetics industry and the improvement of consumer awareness, the claim of cosmetic products is gradually shifting from being conceptual to being effective.
