Application of mid-infrared spectroscopy in the quality control of traditional Chinese medicines.

Chinese herbal medicines are often referred to as Chinese materia medica (CMM). Composite formulae containing mixtures of CMM are prescribed for treatment and prevention of diseases in the practice of traditional Chinese medicine (TCM). Some of the well-known CMM formulae (Fufang in Chinese) are manufactured and marketed as proprietary Chinese medicines (PCM). Quality assessment and assurance of these products are difficult; they are a challenging task. Mid-infrared spectroscopy, a classic molecular structure analysis method, has been innovatively applied in the quality control of TCM, and has gained significant impact and advancement in analytical fields. Infrared fingerprinting features appear particularly suitable for the identification of multicomponent matrices in samples whose chemical integrity has not been altered or destroyed because no extraction procedure is needed. This review summarizes and gives an overall view on the application of mid-infrared and two-dimensional correlation infrared (2D-IR) spectroscopy as well as chemometric techniques in the identification of CMM, investigation of TCM processing procedures, and analysis of herb extracts and preparations.

A unique issue in the standardization of Chinese materia medica: processing.

Processing of Chinese Materia Medica (CMM) is a pharmaceutical technique to fulfill the different requirements of therapy, dispensing and making preparations according to traditional Chinese medicine theory. The aims of processing are to enhance the efficacy and/or reduce the toxicity of crude drugs. Those processed products are named as decoction pieces, which are used in clinics. Therefore, there is a close relationship between processing, safety, and efficacy of Chinese medicines. Some toxicity or side effects are caused by improper processing methods and some are due to improper combination of herbal mixtures. Standardization of processing methods for Chinese herbs is as important as authentication to maintain their quality and ensure their safe use. The objective of this paper is to review the literature covering the current situation and problems of CMM processing as well as recent progress in research in this area. A summary of the most urgent work needed is proposed.

Systematic evaluation of organochlorine pesticide residues in Chinese materia medica.

A systematic evaluation on the levels of organochlorine pesticide residues (OCP) was conducted on four selected, authentic Chinese materia medica, namely: Radix Angelicae Sinensis, Radix Notoginseng, Radix Salviae Miltiorrhizae and Radix Ginseng. Altogether ten representative batches of samples were analysed for each herb. Six batches were collected in the major cultivation areas of the Mainland whilst the remaining four batches were procured in the Hong Kong herbal market. All except Radix Angelicae Sinensis have been identified as containing quintozene and hexachlorocyclohexane in various levels. Hexachlorobenzene and lindane were also reported in samples of Radix Ginseng. The banned pesticide, DDT and its derivatives, was also observed in one of the Radix Notoginseng samples. The investigation will be continued for a target list of common used herbs in Hong Kong. All the results will be gathered and analysed for setting up regulatory permissible limits of OCP residues in Chinese materia medica used in Hong Kong.