Extract, Ointment and Plaster, Common Forms of TCM Prescriptions  
They are medicinal preparations made by decocting drugs in water or vegetable oil and discarding the dregs, for oral or external application. The former includes liquid extract, extract and decocted extract, and the latter ointment and plaster. Among them, liquid extract and extract mostly serve as a mediator for other preparations, such as mixture, syrup, granule and tablet. Here is a brief explanation of decocted extract, ointment and plaster.

Decocted Extract  
It refers to the semi-liquid form of preparation made by decocting the drugs in water repeatedly, discarding the dregs, then concentrating and adding to it refined honey or sugar. Such paste is small in size, high in content, convenient to take and tasty with a nourishing action, applicable to patients with chronic disease and weak constitution, e.g. Lutai Gao, Bazhen Yimu Gao, etc.


Ointment
It refers to the semisolid form of preparation with certain viscosity made by mixing the drug lwder with appropriate matrix, among which the one made with emulsion is also known as emulsive ointment, mostly applicable to the skin, mucous membrane or sores and scabs. Sinceointment bears a certain viscosity, it will gradually soften or melt with drugs slowly absorbed and producing lasting therapeutic effect. It is applicable externally to sores and furuncles, ulcer and masses, and burns as well.
 
Plaster  
It refers to the preparation obtained by boiling drugs in vegetable oil to certain extent, removing the residue, boiling again till it becomes so solid that the dripping water turns to beads, adding to it the yellow lead, mixing up and cooling it down. Before applied to the affected part or point, it should be heated and spreaded over a piece of cloth or paper till it softens. It is applicable to both local and general diseases, e.g. sores, ulcer and masses, injuries from falls, fractures, contusions and strains, rheumatic diseases, waist soreness and abdominal pain as well. The commonly used are Goupi Gao, Nuanqi Gao, etc.