What are the factors affecting purity of these plant sources?
• impurities through air pollution and possible soil contamination
• Microbial factors which arise through soil harvesting as well as from drying and storage environment.
• Mycotoxins can be formed on herbal drugs due to growth of moulds which occur in humid conditions.
• Excessive use of fumigation and pesticide agents for plant protection can lead to unacceptable residues.
The manufacture of high quality herbal drugs requires an effective method to ensure usage of clean herbal raw material.
How is analytical characterization of herbals done?
The hunt for new natural products which can be used as possible sources for manufacture of herbal drugs or as lead compounds is facilitated through modern phytoanalytical and chemical techniques such as gas chromatography, mass spectrometry, liquid chromatography and so on.
This study is done with special emphasis on Asian and European medicinal plants or plants grown in the Alpine region.
These comparative phytochemical and analytical methods help to know better and confirm the relations between various plant taxa. A combination of various approaches like analytical, phytochemistry, pharmacology and chemosystematics provides scope for wide-ranging and cost-effective research on pharmacognostic issues.
The phytoanalytical chromatographic method of analysis gives a total analytical summary of herbals. However, the manufacturer’s specifications for verifying the identity of herbals using chromatographic approach should be in line with the guidelines issued by regulatory bodies.
A brief idea of various types is outlined below.
• Thin Layer Chromatography (TLC)
This method is commonly used for authentication of herbs. It facilitates comparison of the pure reference compounds or authentic sample with the mixtures of compounds separated by TLC.
• Column Chromatography (CC)
This is another separation technique used in organic chemistry and has wide ranging applications in fields of biochemistry, microbiology, biology and medicine.
• High-performance Thin Layer Chromatography (HPTLC)
This approach is widely used in herbal and pharmaceutical industry and is helpful in classification and finding out adulterants in products of herbal origin. It also helps in maintaining quality standards in manufacture of dietary and herbal supplements.
• High-performance Liquid Chromatography (HPLC)
This method is useful for verification and study of herbal substances. It has wide ranging uses like ascertaining purity, comparing claims of raw material suppliers, confirming shelf life of Dietary supplements and Nutraceutials and also the nutritional label of herbal or food product.
Summarizing
Modern phytoanalytical methods are regarded as wonder weapons for identification of herbals; however, complex composition of certain plant extracts may make it difficult to find analytical targets and markers to explain therapeutic and pharmacological effects.
Development of exceedingly sensitive methods apt for biological matrices is a testing task for pharmacokinetic analysis of herbal medicinal products.