[Crystal form issues and development prospects of TCM solid preparations]

As the dominant dosage form in clinical practice of TCM, solid preparations face core challenges concerning quality stability and consistent therapeutic efficacy. Clinical observations have revealed efficacy variations among different preparation forms of the same TCM or even among products of the same preparation from different manufacturers. Such variations are attributed not only to the complexity of the production process but also to the physicochemical states of the drug substances, among which crystal forms likely serve as a critical factor influencing the drug state and subsequent efficacy divergence. TCM crystal forms, as a fundamental microscopic attribute of active ingredients in TCM, directly determine physicochemical properties and biological activities of drugs, representing a root cause of quality fluctuation and efficacy variation. Currently, significant progress has been made in the study of TCM crystal forms based on TCM active ingredients and compound preparations. A comprehensive technical framework encompassing preparation, characterization, and property analysis has been established. Its core value lies in revealing the scientific essence of "identical composition but heterogeneous activity", and it is expected to provide quantitative and precise technical support for quality control across the entire TCM industry chain. However, research on the crystal forms of TCM solid preparations remains a major challenge. Whether it concerns the discovery, characterization, and identification of preferred crystal forms in Chinese patent medicines, or the quality control of crystal forms of Chinese patent medicines and their impact on clinical efficacy, these areas remain largely unexplored territory awaiting further investigation. This article proposed the crystal form issues in TCM solid preparations. It comprehensively reviewed the research landscape of TCM crystal forms, spanning from single components to compound preparations, systematically elucidated the associated technical systems and category characteristics of TCM crystal forms, and innovatively proposed a crystal form-based strategy for quality control. This perspective provides a novel research framework for enhancing the quality control of TCM solid preparations and discovering new formula-derived nanoparticle drugs, holding significant importance for enhancing the standardization of TCM solid preparations, ensuring clinical efficacy, and advancing the development of TCM nanoscience.