Herbs as Raw Materials

(T. Y.  B. Pharm  Unit -I) AS per PCI Syllabus



Herb:

It consists of entire plant or any part of the plant

Herbal Drug :

These consist of plants or any part of plants, usually in unprocessed or crude forms (crude drug) which have medicinal value. They include different parts of plant like entire aerial part, flowers, fruits, seeds, bark, leaves, roots, rhizomes etc. The constituents and their therapeutic activity may be known or unknown.

Herbal drug preparation


They are processed form of herbs. They are derived from herbal drugs by various techniques like extraction, fractionalization, purification, concentration fermentation and may be in the form of powders, extracts, tinctures, fixed oils, volatile oils, resins, gums, etc.
They contain a mixture of various constituents. However pure isolated compounds do not come under this category.



Herbal Medicinal Products (Finished Herbal Products) :


These are the medicinal products which contain exclusive herbal drugs or herbal drug preparations which are made from one or more herbs.

It includes various herbal formulations like tablets, syrups, capsules, semisolid dosage forms, etc. 


They may contain excipients in addition to active ingredients.

Source of herbs:

Herbs or medicinal plants can be obtained from two sources viz:
a) Wild source  b) Cultivated source

a) Wild source :


The plants are obtained from the wild source such as forests, plains, river banks, etc. Obtaining herbs from wild source is my economical, less time consuming, decreased cost of labour, however it also offer various disadvantages such as quality of the plants cannot be predicted due to various environmental changes. The plants will not be uniform in their growth and yielding characteristics. Modern scientific techniques cannot be applied to increase the yield as well as quality. If the plants are obtained continuously from wild source for prolonged periods a may lead to depletion of raw materials from the wild.


b) Cultivated source


In recent times,medicinal plants have been systematically cultivated by applying modern scientific techniques.

Advantages :


•Quality and purity is ensured.
•Better yield and more profit.
•Ensures regular supply of raw material.
Application of modern scientific techniques is possible.

Note: 

Crop planning: Means ensuring regular supply of raw material to the industry.

Application of scientific techniques: It includes tissue culture, genetic engineering, hybridization and germplasm.


a) Selection of herbs :

The species or botanical variety selected for cultivation should be the same as specified in the official Pharmacopoeia or national documents.
In case of newly introduced medicinal plants, the variety selected for cultivation should be identified and documented.

b) Identification and authentication of herbal materials


Botanical identity: The species, subspecies, genus, variety etc of the plant for cultivation should be verified from a qualified botanist / institute and recorded.

Specimens : In case of a new plant with medicinal properties whose identity is not known, a specimen of the plant should be submitted to a national herbarium for identification & documentation.

Seeds and other propagation materials: The suppliers of seeds and other propagation materials should specify all the necessary information relating to the identity, quality as well as their breeding history. The seeds & propagation material should be free from contamination and diseases in order to promote healthy plant growth.

c) Cultivation of medicinal plants


Cultivation of medicinal plants requires intensive care and management as various factors such as environment, soil, irrigation, pests, etc, play a vital role. These factors vary from one plant to another. Scientific documented methods should be followed, if no data available, traditional methods should be adopted and a systematic method should be developed through research.
Good agricultural practices in cultivation (GACP) and conservation agriculture (CA) which aims to  improve, conserve & make more efficient use of natural resources.


d) Collection of herbs


For the collection of medicinal plants, a proper time should be selected. Herbs are selected for collection at a stage when they yield maximum amount of chemical constituents Skilled labour should be employed as they are trained to identify and select the herbs at a proper stage.
The age of the plant also plays a vital factor for their selection. Diseased plants should he rejected, Season of collection should also be given due consideration while selecting the plants for collection.

e) Processing of herbal raw materials 

Processing of herbal raw materials involves various stages from which the crude drugs undergo after harvesting. It can be classified into primary and secondary processing which are further sub categorized as follows. 

Note: 

Cultivation of medicinal plants is also brawn as propagation, Which can be done by sexual and asexual methods.
collection: If mean harvesting of the plant material.