Pharmacognosy - medicinal plants (herbs)
Pharmacognosy - medicinal plants (herbs)

Theme VII: Analysis of extracts

Tincture

What is the tincture?

The tincture is a liquid preparation generally obtained either by using 1 part of the plant or animal drug and 10 parts of the extraction solvent; or 1 part of the plant or animal drug and 5 parts of the extraction solvent.

Production

The tincture is prepared by maceration or percolation (according to the methodology described below) using only alcohol at a concentration suitable for the extraction of the plant or animal drug. It can also be made by dissolving a soft or dry extract (which has been produced using the same concentration of solvent used in the preparation of the tincture by direct extraction) of plant or animal drug in ethanol at a suitable concentration. The tincture is filtered if necessary.

 

The tinctures are usually clear, but may be present a slight sediment which is acceptable if the composition of the tincture doesn’t change significantly.

Production of tincture by maceration

Unless otherwise prescribed, the plant or animal drug to be extracted must be prepared in the adequate sized pieces, mixed with prescribed solvent and leave to stand in a closed vessel for the required time. Then, separating the residue after the extraction of the solvent and, if necessary, put pressure on it. Ultimately can be used two liquids in combination.

Production of tincture by percolation

If necessary, the plant or animal drug to be extracted is reduced to the adequate sized parts, is mixed with a portion of the prescribed extraction solvent and leave to stand for the required time. It´s transferred to the percolator and let it flow at room temperature, being aware of the plant or animal drug extracted is always covered with the rest of the extraction solvent. The residue can be pressed to extract the remaining liquid and added to the percolate.

Tests

- Relative density.

- Alcohol content.

- Methanol and 2 - propanol. Maximum 0.05% V / V of methanol and 0.05% V / V of 2 - propanol, unless specify otherwise in the monograph.

- Dry residue: where applicable, tincture meets to the limits prescribed in the monograph, corrected if necessary, taking into account any excipient used.

Storage

Protected from light.

Labeled

The labeled must contain the following:

For standardized and quantified tincture: the proportion of the starting material used for the liquid extraction or the starting material to the final tincture. The alcohol content in percentage V / V in the final tincture.

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