Pharmacognosy.
Some dictionaries define pharmacognosy as being the study of drugs of plant origin, while others refer to it as the branch of pharmaceutical biology that deals with drugs in their crude or natural state. Used today, the term pharmacognosy focuses on medicines from natural sources and its scope includes the identification or authentication of crude drugs using macroscopical, microscopical or chemical methods.
Methods in pharmacognosy
The European Pharmacopoeia (Ph. Eur.) defines the term pharmacognosy in a different way. The following methods are listed as "Methods in pharmacognosy" in Chapter 2.8 of Ph. Eur. 5.0:
- Ash insoluble in hydrochloric acid
- Foreign matter
- Stomata and stomatal index
- Swelling index
- Water in essential oils
- Foreign esters in essential oils
- Fatty oils and resinified essential oils in essential oils
- Odour and taste of essential oils
- Residue on evaporation of essential oils
- Solubility in alcohol of essential oils
- Assay of 1,8-cineole in essential oils
- Determination of essential oils in vegetable drugs
- Pesticide residues
- Determination of tannins in herbal drugs
- Bitterness value
- Dry residue of extracts
- Loss on drying of extracts
Descriptions of the respective identities can be found under "Identification" in the pertinent monographs.
Established pharmacognostic methods at PhytoLab
PhytoLab is an external testing laboratory, officially recognized in accordance with § 14 of the German Drug Law (AMG) and accredited in accordance with ISO 17025 and GLP principles 2 and 7 by the Governmental Recognition Office for Foodstuffs Monitoring (SAL) and, as such, fulfils the requirements of Council Directive 93/99/EEC, is equipped with state-of-the-art technical instruments and facilities, employs highly qualified personnel and specialises in the analysis of plants and plant-based products. PhytoLab has established all of the methods in pharmacognosy listed in Ph. Eur. as routine procedures. Furthermore, PhytoLab is also highly qualified for the performance of pharmacognostic methods in narrower terms, i.e. for identification purposes. More than 10 years of experience, an extensive collection of authentic drugs, modern equipment and staff specifically trained in the application of these methods guarantee irrefutable establishment of identity and purity.
Identification and purity are verified by means of the following:
- Odour
- Taste
- Macroscopic characteristics
- Microscopic characteristics
The macroscopic and microscopic characteristics can be recorded using an ultra-modern, computer-aided video documentation system and made available as and when needed. The results are substantiated by means of chemotaxonomic tests for the presence of the characteristic constituents. The following methods are available at PhytoLab for this:
- Thin-layer chromatographs
- Chemical identification reactions
- HPLC fingerprints
- GC fingerprints
Correct identification is of paramount importance to ensure that similar plants, which are ineffective or even toxic, are never used or mixed in instead of the medicinal plant.
Pharmacognosy and "Traditional Chinese Medicine" (TCM)
Pharmacognosy and "Traditional Chinese Medicine" (TCM) Pharmacognosy in the field of Traditional Chinese Medicine (TCM) is of particular interest at the moment. Greater attention is currently being given to Traditional Chinese Medicine in Europe as well, with growing numbers of well-qualified doctors, strong representation in the media and verified therapeutic successes. However, there are very few laboratories capable of complying with the stringent requirements for identification and purity testing of the TCM drugs. These are routine tests at PhytoLab, where they are performed for a number of different TCM drug suppliers and on the TCM drugs produced within the framework of a cultivation project at Freising Technical University.
