Summary

Initially, people used only fresh or dried plants or an infusion made from them. The next step was to introduce extracts. This made it possible to achieve a higher concentration of active substances and to facilitate dosing and use by patients. An extract is a concentrated plant or animal preparation obtained by etching a suitable raw material with a solvent (most often water or ethanol, sometimes with ethyl ether) and their mixtures. Depending on the degree of compaction and the method of preparation, we distinguish several types: liquid extracts, tinctures, thick extracts, oleoresins, dry extracts. There are different methods for determining the active ingredient content of extracts, the most common of which are standardization and DER.

The use of the healing properties of herbs is as old as human history. Or maybe even older?

Dog and cat owners have probably seen their pets eat grass often. And these are typical predators. It turns out that the grass helps them digestion and eliminates digestive ailments. There are also other interesting observations from the animal world. For example, they described a strange-behaving elephant that traveled more than 20 km from its herd to eat a plant that was never part of its usual diet. Soon after, she gave birth. It turned out that local tribes also use this plant to facilitate childbirth. Lemurs have also been observed gnawing poisonous centipedes and then rubbing their secretions to protect themselves from parasites. So the use of natural medicines is not just about humans.

Initially, only fresh or dried plants or their infusion were used.

The next step was to introduce extracts and extracts. This made it possible to achieve a higher concentration of active substances and to facilitate dosing and use by patients.

But what are extracts?

An extract is a concentrated plant or animal preparation obtained by etching a suitable raw material with a solvent (most often with water or ethanol, sometimes with ethyl ether) and their mixtures. The obtained extract is then subjected to the concentration process in order to obtain the appropriate concentration of active substances. The resulting product is called a galenic drug.

Extracts are preparations with a liquid consistency (liquid extracts and tinctures), semi-solid (dense extracts and oleoresins) and solid (dry extracts).

  • Liquid extracts (Latin extractafluida) – preparations with a liquid consistency, in which usually 1 part of their weight or volume corresponds to 1 part of dried plant substances or substances of animal origin. They can also be obtained by dissolving a dry extract. Liquid extracts are obtained by the percolation method, i.e. extraction of the raw material with a flowing solvent stream.
  • Tinctures (Latin tincturae) – liquid preparations in which 1 part of the raw material is etched with 5 or 10 parts of a solvent. Tinctures are obtained by the method of percolation or maceration, i.e. pouring the raw material with alcohol of the appropriate concentration.
  • Dense extracts (Latin extractaspissa) – semi-solid products obtained by partial solvent evaporation.
  • Oleoresins (Latin oleoresin) – semi-solid solutions of a resin in an essential oil and / or fatty oil obtained by partial evaporation of the solvent.
  • Dry extracts (Latin extracta sicca) – preparations of solid consistency obtained by complete evaporation of the solvent.

Liquid extracts are usually components of liquid forms of drugs (syrups, drops, etc.), and thick extracts, oleoresins and dry extracts are most often one of the ingredients of capsules or tablets.

In order for us to be able to assess the value of a given extract, the manufacturer often standardizes its products.

The standardization of the plant material allows to determine the amount of active compounds that exert a therapeutic effect (e.g. the content of essential oil in a given raw material) and sometimes undesirable components (e.g. erucic acid in rapeseed oil).

Standardization is most often based on the results of chemical tests.

Standardization is performed on the basis of pharmacopoeial standards or the quality standards of a given raw material. The content is determined by analytical methods, and the purity of the raw material can also be assessed.

The standardized preparation contains a strictly defined amount of ingredients exerting a therapeutic effect, e.g. 1 sachet contains 1000 mg of dried rosehips, standardized for 20% of vitamin C, i.e. 200 mg of vitamin C in 1 sachet.

Standardization is also important in the case of extracts with a strong therapeutic effect, the overdosing of which may be dangerous for the patient. An example is the content of cardiac glycosides in the extracts of the lily of the valley or the foxglove.

Another way of expressing the value of the extract is through the DER, which you sometimes see on herbal medicine packages.

DER (Drug Extract Ratio) is the ratio of the amount of plant material to the amount of the obtained extract.

Its purpose is to enable the comparison of medicines containing the same substance but obtained in different ways (e.g. extracts with different concentration levels). The entry 10: 1 means that 10 parts of the plant were used for 1 part of the extract.

DER allows you to calculate the amount of plant material that corresponds to e.g. 1 capsule of a given drug. If the capsule contains 100 mg of ginseng extractDER 20: 1, it means that 2 g of dry raw material (20 × 100 mg / 1 = 2 g) was used to prepare the capsule.

In a situation where there are a lot of drugs and dietary supplements containing plant substances on the market, it is worth paying attention to such information provided on the packaging because they make it easier to make a rational choice of the best product.

AUTHOR: Dr n. farm. Andrzej Tarasiuk