To better define the pharmacognosy it can be thought of as a multidisciplinary collector. It is a discipline that deals with recognition:
of drugs, or to know for each drug the source, the macro and microscopic morphological aspects;
of the drug and the source even after working processes, for example drying;
authenticity and drug contamination, starting from an analysis of its characteristic components;
of contamination or adulteration of the drug, bearing in mind that both affect its quality, which will no longer be optimal.
The recognition process leads us to identify the correct origin and authenticity of the drug, assess the possible frauds applied to the drug itself and express a quality judgment that is also dependent on the identification of the drug itself. If the recognition presupposes criteria of evaluation of a botanical type, for example the tissues, associated with a macro and microscopic classification of the drug, also requires microbiological assessments, aimed at evaluating the quality, once again, of the health use of the drug.
If a certain drug has antiviral properties, such as Echinacea, once recognized macro and microscopically, its health properties must be evaluated; in fact it can happen that the plant from which the drug derives has been badly cultivated, in poor weather conditions and that they have not allowed the development of antiviral principles. To evaluate this it is necessary to examine the efficacy of the drug in in vitro, using microbiological tests. If a certain amount of drugs has to determine a certain result, I go to make the tests to see if it has excellent, good, scarce or null properties. Chemical assessments are also necessary, especially if I have to determine how much that drug is antiviral. I need to know the most appropriate extraction and identification models to evaluate the active principles, therefore phytochemical evaluation criteria. If I know how much active ingredient per unit of weight I have to get with the best extraction method, I can evaluate if the drug is excellent, good or of little value and determine if it has been grown in inappropriate conditions, treated or contaminated with unusual pesticides or if it has suffered post-harvest degradation. An evaluation must therefore also be made on the basis of the chemical characterization of the drug. Finally, I can and must assess whether the drug can be toxic to the human body; toxicity values are determined in vitro, in vivo on guinea pigs and also at clinical level in humans, in order to outline a wide range of toxicity values.
These tools serve pharmacognosy to outline a complete picture of drug identification in its quality and identity for its health application. Therefore, pharmacognosy can be defined as a multidisciplinary subject that draws on botanical, chemical, biological, toxicological and microbiological aspects, to determine the identity and quality of the drug at a microscopic and macroscopic, phytochemical, biological and toxicological level.
