Extraction Technologies For Medicinal And Aromatic Plants - Unido

14 QUALITY CONTROL OF MEDICINAL AND AROMATIC PLANTS AND THEIR EXTRACTED PRODUCTS
BY HPLC AND HIGH PERFORMANCE THIN LAYER CHROMATOGRAPHY
nutraceuticals. South America, which has given the world some of the all-time
great plant medicines like quinine and pilocarpine, follows the medical system
of North America. Australia has a strong impact from Chinese medicines on the
continent which is otherwise dominated by the modern system of medicine.
14.2 Quality Control of Medicinal Plants and their
Products
The quality control of consumer products has become more challenging
and demanding. The quality considerations of drugs are the most
stringent among all consumer products. The purity of active pharmaceutical
ingredients has been stretched to an all-time high with more and more restrictions
on the level of the impurities. The situation is opposingly different in
the case of plant-derived medicine, where we are still striving to defi ne specifi
cations to ensure consistency and safety. Therefore, the standards of plant
drugs are more relaxed and are in the process of development. The inherent
problems of plant drugs are obvious; unlike single chemical entities of modern
drugs, they are combinations of infi nite chemical molecules, known and
unknown; the knowledge of the active components is incomplete; the natural
variations in content and quantity of the chemical constituents are large and
exercising a precise control is impractical; and the complete chemical profi ling
of plant drugs is beyond scope. Therefore, laying standards for such drugs is
not an easy task and a comprehensive system of standards cannot be laid
down for such drugs. As our knowledge of plant drugs will advance, the standards
for them will become more meaningful and complete.
The quality issue of plant drugs was irrelevant in ancient times
when these medicines were dispensed by the medical men for their patients.
However, the issue has taken front seat with the commercialization of
plant drugs. The matter has been further complicated by the vested interest
of manufacturers who are out to exploit the loopholes in the standards and
laws governing the production and distribution of plant drugs.
Several national and international agencies have prioritized the
issue of assuring the quality of plant drugs. The effort of the World Health
Organization is outstanding: over 20 years ago it fi rst published Quality control
methods for medicinal plant materials, which has been regularly updated
and followed by a series of monographs on globally important medicinal
plants.
The quality of a plant product cannot be assured without assuring
the quality of the raw material. Also required to ensure quality products
are in-process control, quality control of the fi nished product, good manufacturing
practice (GMP) controls and process validation. In this regard, it is
imperative to defi ne specifi cations of raw materials to minimize variations
in the quality of fi nished products and to achieve consistency. The specifi ca-
240