Natural products in various forms have been used since immemorial time for the treatment of pathological conditions or for health benefits all over the
world
(1).
In western countries where an allopathic system of medicine substituted almost completely the use of crude extracts, plant derived compounds constitute 25% of the existing drugs.
Today
many extracts apart from the biological and clinical documentation which is normally insufficient are also
poorly chemically characterized being not identified the active constituents, the constancy and stability are erratic and so on. For these reasons many extracts with
totally different composition are claiming the same therapeutic properties. It is clear that to obtain
biological reproducible data in terms of safety and efficacy the active ingredients must be the same over the time, must be stable and devoid of unpredictable toxicity or side effects. The question is to prepare standardized extracts,
identifying the active constituents and controlling also the unknown substances in terms of stability and constancy.
Standardization is a hard task which start from the biomass obtained possibly cultivating the plant according to
Good Agricultural Practice (GAP), to the chemical isolation and characterization of active reference substances, to setting up validated analytical methods and finally to
Good Manufacturing Practice (GMP) production of the final ingredient.

Variables to be managed for the preparation of a standardized extract.
As far as the standardization of extracts is concerned, the aim has to be the
reproducibility of all the chemical components contained in an extract, including the unknown ones. An extract normally contains several classes of substances, some of which are
active principles, whilst others can be their
natural vehicles or they are
inert substances.
(1) Bombardelli E., Bombardelli V., Fitoterapia
76, 495-507 (2005)
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