On May 9, 2026, significant progress was made in the research on powder surface properties. As core indicators, hygroscopicity and wettability are of great significance to the R&D, production and storage of pharmaceutical preparations. Hygroscopicity relates to the characteristics of powder adsorbing water vapor, and critical relative humidity (CRH) is a key parameter. The smaller the CRH value, the easier it is to absorb moisture, and the hygroscopicity of drugs usually increases significantly after mixing. Wettability reflects the spreading ability of liquid on powder surface. The smaller the contact angle, the better the wettability, which directly affects drug dissolution and bioavailability. The study clarifies that molecular polarity, particle size, temperature, humidity and excipient compatibility all affect the two properties. Gravimetric method and contact angle method are common determination methods. Moderate moisture absorption can slightly improve wettability, while excessive moisture absorption tends to cause agglomeration and reduce wetting effect. This achievement provides a scientific basis for formulation design, process optimization and quality control, helping to improve the stability and efficacy of preparations. For more information, please visit: https://www.tiktok.com/@mia_iota/video/7597717976720149782