Extraction Technologies for Medicinal and Aromatic ... - Capacity4Dev
Extraction Technologies for Medicinal and Aromatic ... - Capacity4Dev
Extraction Technologies for Medicinal and Aromatic ... - Capacity4Dev
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EXTRACTION TECHNOLOGIES FOR MEDICINAL AND AROMATIC PLANTS<br />
3.3 Factors Affecting the Choice of <strong>Extraction</strong><br />
Process<br />
The choice of the process to be used <strong>for</strong> the extraction of a<br />
drug depends on a number of factors.<br />
3.3.1 Nature of the Crude Drug<br />
The choice to use maceration or percolation primarily depends<br />
upon the nature <strong>and</strong> characteristics of the crude drugs to be extracted.<br />
There<strong>for</strong>e, knowledge of the type of organs <strong>and</strong> tissues of the plant matter<br />
is essential <strong>for</strong> achieving the best result.<br />
3.3.2 Stability of the Crude Drug<br />
Continuous hot extraction procedures should be avoided when<br />
constituents of the drug are thermolabile.<br />
3.3.3 Cost of the Crude Drug<br />
When the crude drug is expensive (e.g. ginger), it is desirable<br />
to obtain complete extraction. There<strong>for</strong>e, from the economic point of view,<br />
percolation should be used. For inexpensive drugs, maceration, despite its<br />
lower effi ciency, is acceptable in view of its lower cost.<br />
3.3.4 Solvent<br />
Selection of the solvent depends on the solubility of the desired<br />
components of the material. If the constituents dem<strong>and</strong> a solvent<br />
other than a pure boiling solvent or an azeotrope, continuous extraction<br />
should be used.<br />
3.3.5 Concentration of the Product<br />
Dilute products such as tinctures can be made by maceration<br />
or percolation. For semi-concentrated preparations, the more effi cient percolation<br />
process is used. Concentrated preparations, such as liquid or dry<br />
extracts, are made by percolation.<br />
3.3.6 Recovery of Solvent<br />
Solvent is preferably recovered under reduced pressure to save<br />
thermolabile constituents.<br />
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