Syrupus Picis Liquidae. U. S. Syrup of Tar. Syr. Pic. Liq.
Syrupus cum aqua picea; Syrupus Piceus; Sirop de Goudron, Fr. Cod.; Theersirup, G.; Jarabe de brea, Sp.
"Tar, five grammes [or 77 grains]; Alcohol, fifty mils [or 1 fluidounce, 331 minims]; Magnesium Carbonate, ten grammes [or 154 grains]; Sugar, eight hundred, and fifty grammes [or 29 ounces av., 430 grains]; Water, a sufficient quantity, to make one thousand mils [or 33 fluidounces, 6 ½ fluidrachms]. Dissolve the tar in the alcohol, add the magnesium carbonate and fifty grammes [or 1 ounce av., 334 grains] of sugar, and after thorough trituration add four hundred and ten mils [or 13 fluid-ounces, 415 minims] of water. Stir the mixture occasionally during two hours and then filter it, returning the filtrate to the filter until the liquid is clear. Dissolve the remainder of the sugar in the clear filtrate obtained from the treatment of the tar, and strain the syrup, adding sufficient water through the strainer to make the product measure one thousand mils [or 33 fluidounces, 6 ½ fluidrachms]. Syrup of Tar may also be made in the following manner: Prepare a percolator in the manner described under Syrupus. Pour the clear filtered liquid obtained from the treatment of the tar as directed above upon the remainder of the sugar, return the first portions of the percolate until it runs through clear, and, when all the percolate has passed, follow it with water until the sugar is all dissolved and the product measures one thousand mils [or 33 fluidounces, 6½ fluidrachms]. Mix thoroughly." U. S.
In many sections of our country this syrup has been largely used. The process of the U. S. P. IX is an improvement on the one formerly official; the proportion of tar being reduced from 75 Gm. to 5 Gm. It is similar to the U. S. P. VIII process except that the washing of the tar to remove acid constituents has been omitted because these would not be present in a tar which conforms to the U. S. P. tests. The tar is dissolved in alcohol, magnesium carbonate and a little sugar added, the mixture filtered, and more sugar dissolved with the aid of a gentle heat. This syrup affords an excellent method of administering small quantities of tar in the milder forms of subacute or chronic bronchitis.
Dose, from one to two fluidrachms (3.75-7.5 mils).