Lozenges or Troches, are small articles of confectionery, sometimes medicated, and usually made up of the form of thick wafers. The basis of their composition is refined sugar, which is finely pulverised and sifted, then mixed up in a mortar, with just a sufficient quantity of thick mucilage, to make a very firm paste; to which is added the essential oil or other flavouring ingredient or medicament. When the paste, so made, is of the right consistence to be rolled out into a solid and smooth sheet, that operation should be quickly performed by a cylindrical roller, the ends of which should run upon slips or projections above the board, of the thickness of the intended lozenge. Thus rolled out, the lozenges should be quickly cut out with the punch or cutter; which is usually the hollow frustrum of a cone, with sharp edges at the narrow end,and is made either of tinned plate, iron, or steel. As soon as these are cut cut, the remaining pieces which formed the interstices between the lozenges, should be rolled up, or beaten together in a mortar, then rolled and cut out again; and this operation continued, until the whole material is used up. But if further quantities are required of the article under operation, then the remnants of one cutting may be added to the succeeding batch.
In the pharmacopeias, gum tragacanth is recommended as the mucilage to be used in making medicinal lozenges. Lozenge makers, however, rarely use this gum, as besides being much dearer, it is inconvenient in use, and does not make so elegant a lozenge as gum Arabic or Senegal. The latter when in proper quantity, (which is about one ounce of very thick mucilage to a pound of finely powdered sugar,) gives to the lozenges made therewith, a semi-transparency and hardness, which is regarded in the trade as a test of a well-manufactured article. When essential oils, (such as peppermint, roses, cinnamon, etc.) are used as the flavouring ingredients, they should not be added until the paste is otherwise nearly completed, as their great volatility causes a waste of their essential properties when long under the hands of the operator. In making lozenges containing balsams, such as the tolu, the balsams may be advantageously mixed with the mucilage; and those in which powders, such as ginger are to be mixed, the manner of performing it is a matter of indifference.