Products
Extracts are contained in numerous medicinal products, for example, in tablets, capsules, drops, creams, ointments, and injection solutions (selection). They are also used in the preparation of cosmetics, dietary supplements, foods, and medical devices.
Structure and properties
Extracts are extracts made with a solvent (= extracting agent) such as water, ethanol, methanol, fatty oils, and carbon dioxide usually from plant parts (medicinal drugs), animal materials, or other natural materials (e.g., fungi, microorganisms). These may be fresh or dried. Manufacturing methods include maceration (pickling) and percolation (passing through). Depending on the nature are distinguished:
- Liquid extracts: Fluid extracts (Extracta fluida) and tinctures (Tincturae).
- Semi-solid extracts: Viscous extracts / thick extracts (Extracta spissa), oleoresins (Oleoresina).
- Solid extracts: dry extracts (Extracta sicca).
The semi-solid and solid extracts can be obtained by evaporation of the liquid extracts. Dry extracts are usually hygroscopic. Since the starting materials (eg, herb, flowers, leaves, roots, rhizomes) are natural substances with a variable content of ingredients, extracts are also standardized to lead substances. They are referred to as standardized or adjusted extracts. This is done with the aim of achieving a consistent therapeutic effect. Extracts produced in different ways can only be compared to a limited extent. Quantified extracts are adjusted to a defined range of active lead substances. This is done by mixing batches of extracts. The addition of inert excipients with the purpose of dilution is also possible. Extracts can be used to preserve and concentrate perishable fresh plant parts. To avoid side effects, undesirable ingredients can be removed during the extraction process (e.g., pyrrolizidine alkaloids).
Effects
Unlike traditional medicines, which usually contain only one or a few active ingredients, extracts are multisubstance mixtures. They have comparable mechanisms of action to other drugs, i.e., they interact with drug targets in the organism.
Indications for use
Extracts have a very great importance in phytotherapy, among other fields.
Dosage
According to the professional information. One advantage of extracts is that, unlike medicinal drugs, no preparation is required because the extraction has already taken place. In addition, extracts are concentrates, of which only a small amount needs to be administered. For example, chamomile flowers occupy a large volume, while the extract is much smaller.
Adverse effects
Herbal extracts are usually somewhat better tolerated than drugs with chemically synthesized active ingredients. However, they can also cause side effects and interactions, and highly potent plant extracts exist (e.g., opium, nightshade, digitalis), which must be precisely dosed.
