With the increasing demand for traditional Chinese medicines(TCMs), the resources of TCMs are gradually rare, and the phenomenon that TCMs fake is a common occurrence. Consequently, we need to urgently improve identification technique of TCMs. Terahertz time-domain spectroscopy(THz-TDS) is a newly emerging spectroscopy technology that has been widely used in image, security inspection, biological detection, medicine, material technology, aerospace, oil exploration and other fields. Which is currently used as a simple and quick method to identify the origins, fake products, processed products and pesticide residues of TCMs, hence, it plays a significant role in supplementing and improving the quality control levels of TCMs. In this paper, the composition principle of THz-TDS and its advantages in authentification of TCMs have been summarized. Additionally, the current situation and application prospects of THz-TDS in the field of TCM identification have also been reviewed.
Drug Contamination ; Drugs, Chinese Herbal/analysis* ; Medicine, Chinese Traditional ; Pesticide Residues/analysis* ; Quality Control ; Spectrum Analysis ; Terahertz Spectroscopy

Polymorphism of drug is known to influence the stability, dissolution, bioavailability and other performance characteristics of the products. Therefore, the crystal form of the drug must be identified and determined in order to ensure consistent product performance. Even if the identification and characterization of crystal forms are performed thoroughly and the effective crystal form is selected for preparation, it is important to ensure that the effective crystal form in the final product remains unchanged. Therefore, it is essential to quantitate the content of the effective crystal form in the product to control the quality and performance of them. X-ray powder diffraction, FT-Raman, mid-IR, near-IR, terahertz pulsed spectroscopy, solid-state NMR spectroscopy, and DSC are the quantitative methods of crystal form used in the recent 10 years. This review briefly highlights the basic principles and the progress of these methods and discusses the perspective as they apply to pharmaceutical research and development.
Calorimetry, Differential Scanning ; methods ; Chemistry, Pharmaceutical ; methods ; Crystallization ; Fourier Analysis ; Magnetic Resonance Spectroscopy ; methods ; Pharmaceutical Preparations ; chemistry ; Spectroscopy, Fourier Transform Infrared ; methods ; Spectroscopy, Near-Infrared ; methods ; Spectrum Analysis, Raman ; methods ; Technology, Pharmaceutical ; methods ; Terahertz Spectroscopy ; methods ; X-Ray Diffraction ; methods