|
|
It is the process of steeping or softening the medicinal substance in some menstruum or solvent for a considerable time, under normal conditions of temperature and pressure.
Conditions:--
1. Menstruum—alcohol as well as water.
2. Normal temperature and pressure.
3. Drug is in contact with vehicle for a long time.
4. The marc is pressed after removing the liquid portion.
Menstruum.— A liquid capable of penetrating the tissues of drug and dissolving the active principle.
Marc.— The inert, fibrous and insoluble matter remaining after maceration, percolation or after any other form of extraction of the juice from drugs and other substances.
Magma.— The thick residue or the soft doughty mass (molten mass) resulting from the expression of the fluid part of certain substances. (pounded fresh plant).
Digestion.— When the maceration is done in hot liquid it is known as digestion.
Details.— This process is preferable in the treatment of large quantities of drug material, requiring ample time for the extraction of medicinal properties such as gummy and mucilaginous substances and those having much viscid juice which do not allow alcohol to penetrate the mass readily, as in the process of percolation.
The moisture of the drug substance, having been previously ascertained, as already directed, the drug material reduced to magma (or in its natural state if not reducable) should be placed into a macerating jar, or a wide-mouthed bottle. The prescribed quantity of the solvent can be now added to it, covering the whole mass, if possible. The jar or bottle should be carefully stoppered or sealed to prevent evaporation, placed in dark room of ordinary temperature and shaken every day. The time necessary for the extraction and solution of the medicinal substance is variable, and it is safe to allow the process of maceration to continue from two to four weeks, according to the nature of the material. After this period, the clear liquid above can be decanted off and the residue can be pressed out through a piece of linen cloth or bag, adding more of the prescribed menstruum, if necessary, to make the required volume.
In case of viscid and mucilaginous drug material, which is not readily acted on by alcohol, only one half of the solvent prepared for the purpose should be used first. After the maceration as directed, the residue can be pressed out. The undissolved residual substance should be lightly triturated in a mortar, adding twice its bulk of finely powdered green glass and with the remaining half of the solvent, the whole thing can be subjected to the process of percolation next to be described. After percolation and subsequent filtration, the clear liquid can be added to that previously decanted and preserve, now completed tincture in a well closed bottle in a dark and cool place. The contraction of volume by the addition of water and alcohol and the increase in volume due to the liquifaction of the medicinal substances are always to be compensated for according to the formula referring to each drug in part II.
|
|
|
----
Link Exchange