Global market for medicinal plants is growing exponentially as plant materials are being increasingly used both in developing countries and in the industrialized world. Today there is a substantial market for herbal drugs both as traditional medicines and in modern medicine. Their widespread availability and lack of effective machinery to regulate manufacturing practices and quality…

Chromatography is the science which studies the separation of molecules based on differences in their structure and/or composition. In general it involves moving (in a mobile phase) preparation of materials to be separated over a stationary support. Based on their differential affinity between the mobile and stationary phase, molecules in the preparation get separated between…

To ensure quality of herbal drugs, it is necessary not only to establish the identity, but also to ensure batch-to-batch reproducibility. Apart from macroscopic and microscopic evaluation, tests to identify principal chemical groups are the next priority. These cover identification and characterization of the crude drug with respect to phytochemical constituents. Several analytical techniques are…

Parasites, microbial contaminants, mycotoxins and endotoxins are the classes of biological contaminants likely to be found in herbal materials. A large number of bacteria and moulds often originating in soil or derived from manure are found in herbal materials. Some of them form the naturally occurring microflora of medicinal plants of which aerobic spore-forming bacteria…

Herbs and herbal products ideally need to be free of pesticides, fumigants and other hazardous contaminants. At best they may be controlled for the absence of unsafe levels. Herbal drugs are prone to pesticide residues, which accumulate from agricultural practices, such as spraying, treatment of soils during cultivation and administration of fumigants during storage. Presence…

Crude drugs may be processed to separate crude fibre, which is a means of concentrating the more resistant cellular material of drugs for microscopic examination. This is especially applicable when the amount of foreign matter in a powder is small. Preparing a crude fibre concentrates the resistant parts of adulterants in a small amount of…

The ash remaining following ignition of herbal materials is a measure of the total amount of the inorganic material left after burning. For some drugs this value gives an indication of the care taken in the preparation of the drug. Adulteration with mineral matter will give higher ash values than for pure unadulterated drug. Determination…

The determination of matter extractable into solvents such as water, alcohol and ether is generally used for evaluating plant drugs, the constituents of which are not readily estimated by chemical or biological methods. Extractive values thus provide assay for drugs such as linseed, which contain fixed oil as an important constituent. Here ether-soluble extractive is…

Crude drugs containing volatile oils are mostly characterized by typical odoriferous nature. Because they are considered the ‘essence’ of herbal material and are often biologically active, they are also known as essential oils. Chemically usually composed of mixtures of monoterpenes, sesquiterpenes and their oxygenated derivatives, they are volatile at room temperature. For volatile oil-bearing crude…

An excess of water in herbal materials encourages microbial growth, presence of fungi or insects and deterioration following hydrolysis. At suitable temperatures, enzymes are activated leading to hydrolytic degradation of active constituents (e.g. digitalis). As most vegetable drugs contain all the food requirements for the growth of moulds, insects and mites, deterioration is very rapid…