More than in other areas, pharmaceutical formulation is paramount in phytotherapy. By pharmaceutical formulation, we mean the form of administration (liquid solution, capsules, tablets, powder, etc.) and consequently the manufacturing and absorption mode of the chosen plant. In phytotherapy, there are a number of pharmaceutical formulations, not all of which are equivalent in terms of bioavailability, meaning the quantity and capacity of absorption of the active principles. Before choosing a dietary supplement in phytotherapy, it is important to know what you are buying and what you can expect from it.
Infusions and Herbal Teas
This is the most popular and widely used form in phytotherapy. Commonly used plants can be consumed in the form of herbal tea (such as thyme, rosemary, chamomile, etc.). Infusion involves steeping the dried plant (in bulk or in bags) in simmering water for about ten minutes. The substances extracted by this process are hydrophilic molecules, soluble in water. The parts used in infusion are most often the leaves or flowers of the chosen plant.
Decoctions
Similar to infusion, for decoction, a mixture of cold water and dried plant is brought to a boil and then allowed to simmer for about ten minutes. The parts used in decoction are often the bark or roots of the chosen plant. Decoction allows the extraction of active principles that are less readily available than in leaves or flowers.
Mother Tincture
The mother tincture is prepared by macerating fresh plants in alcohol (40 to 60°) for about 1 month. During this maceration, only the alcohol-soluble active principles of the chosen plant dissolve in the alcohol. They are therefore available when ingesting this mother tincture. The mother tincture is consumed in very small quantities (a few drops per day) diluted in water.
Extracts
Extracts are obtained by macerating the chosen plant in an aqueous or alcoholic solution. The mixture is then filtered and evaporated to retain only the dry substance. Extracts have the advantage of guaranteeing a certain concentration of active principle.
Capsules or Tablets
Capsules are filled with powder from the chosen plant. This powder is made from the entire plant or certain parts of the dried plant. Excipients may be added to this plant powder to achieve a certain weight per capsule while respecting the intended quantities of active principle per capsule. Tablets are also made with plant powder or dry extract and excipients. Only the manufacturing method differs. Indeed, to make a tablet, the ingredients are processed in presses. Tablets are often consolidated with various coating agents of different natures and qualities, which prevent the tablet from disintegrating. Like capsules, tablet manufacturing follows precise specifications that allow for precise dosages of active principles.
Syrups
This is a somewhat archaic method of preservation, as it involves making a decoction or infusion of the chosen plant and adding sugar to promote its preservation. The parts of the plant used will depend on the basic preparation: leaves or flowers for a syrup from an infusion, and bark or roots for a syrup from a decoction. Syrups raise issues regarding the quality of the sugar used (glucose syrup, cane sugar, etc.) and the amount of sugar ingested (1 kg of sugar for 1 kg of plants).
Essential Oils
Essential oil is a substance contained within the cells of the plant itself. It is extracted by distilling the active parts of the plant that contain this aromatic essence (bark, roots, seeds, etc.). Essential oil needs a preservation medium. Vegetable oil is often used as a neutral carrier. Other extraction techniques exist but they all result in the preservation of the aromatic essence in an oil. Essential oils are used internally (orally) and/or externally. They are highly concentrated active substances that should be handled with care. Indeed, some essential oils are unsuitable for oral consumption even though they are effective externally. Others cannot be used undiluted. It is therefore important to consult a qualified health practitioner or refer to a recognized usage guide to optimize the use of essential oils. Essential oils can be used in diffusion, massage and friction, baths, cooking, etc.