Despite advancements in analytical technologies, the complex nature of cosmetic matrices, coupled with the presence of diverse and trace unauthorized additives, hinders the application of these technologies in cosmetics analysis. This not only impedes effective regulation of cosmetics but also leads to the continual infiltration of illegal products into the market, posing serious health risks to consumers. The establishment of cosmetic regulations is often based on extensive scientific experiments, resulting in a certain degree of latency. Therefore, timely advancement in laboratory research is crucial to ensure the timely update and adaptability of regulations. A comprehensive understanding of the composition of cosmetic matrices and their pretreatment technologies is vital for enhancing the efficiency and accuracy of cosmetic detection. Drawing upon the China National Medical Products Administration’s 2021 Cosmetic Classification Rules and Classification Catalogue, we streamline the wide array of cosmetics into four principal categories based on the following compositions: emulsified, liquid, powdered, and wax-based cosmetics. In this review, the characteristics, compositional elements, and physicochemical properties inherent to each category, as well as an extensive overview of the evolution of pretreatment methods for different categories, will be explored. Our objective is to provide a clear and comprehensive guide, equipping researchers with profound insights into the core compositions and pretreatment methods of cosmetics, which will in turn advance cosmetic analysis and improve detection and regulatory approaches in the industry.

Injectable sodium hyaluronate (NaHA) is extensively utilized in aesthetic medicine as a dermal hydrating agent. However, there are few standardized, human-relevant preclinical methods that can reliably evaluate the moisturizing performance of those products. Existing animal and simplified cell-based models show restricted physiological relevance and insufficient sensitivity. To address this gap, we established a depot-mimicking reconstructed human full-thickness skin (RhFS) platform incorporating an inclusion-based intradermal delivery strategy. Instead of conventional mixing, this strategy mimics the clinical “depot effect” of intradermal injection, allowing for the simultaneous assessment of cellular responses and tissue-level hydration dynamics. It forms a localized NaHA depot within the dermal compartment of RhFS and preserves spatial hydration gradients, which are lost when NaHA is mixed homogenously. The platform integrates physicochemical characterization of polymer-bound water states with cellular and tissue-level functional readouts. By quantifying key biomarkers, including CD44, aquaporin-3 (AQP3), and natural moisturizing factors (NMFs), our results demonstrate that the inclusion-based delivery strategy significantly outperforms conventional mixing approaches in activating epidermal hydration pathways. Crucially, this platform effectively distinguished the moisturizing efficacy of multiple commercial NaHA formulas, thereby revealing a structure-activity relationship between water-binding states and biological outcomes. Overall, this study presents a reproducible, mechanism-informed, and human-relevant framework for preclinical performance evaluation of NaHA-based injectable biomaterials and provides a sensitive alternative to conventional animal-based approaches.