Extract of Cincho′na

Syn. Extract of bark . Three simple extracts, prepared respectively from YELLOW , PALE , and RED CINCHONA , are given in Ph. L.:— Prep. 1. (From CALISAYA or YELLOW BARK :— Extract of cinchona , E. of yellow c. , E. of heart-leaved c. ; Extractum cinch onæ , L.)— a. Extractum cinch onæ flavæ liquidum (B. P.). Yellow cinchona bark in coarse powder, 16; distilled water, a sufficiency; rectified spirit, 1; macerate the bark in 40 of water for twenty-four hours, then pack in a percolator, and add water until 240 have pa ed through, or until the bark is exhausted; evaporate the liquor to 20, at a temperature not exceeding 160°; then filter, and continue the evaporation to 3, or until the sp. gr. of the liquid is 1·200; when cold, add the spirit gradually, constantly stirring. Sp. gr. 1·100.— Dose , 10 to 30 minims. b. (Ph. L.) Yellow cinchona (coarsely bruised), 3 lbs.; distilled water (temperate), 4 pints; macerate for 24 hours (constantly stirring), and strain through linen; what remains, again macerate in water, 1 quart, for 24 hours, and strain; evaporate the mixed liquids to a proper consistence. Obs. The aqueous extracts of cinchona bark po e little medicinal virtue, owing to the insolubility of the alkaloids (quinine, cinchonine, .) in water, and also from the rapid oxidation of their extractive matter, when exposed in solution to the joint action of heat and atmospheric oxygen.— Dose , 5 gr. to 1 ⁄ 2 dr., in mixtures, faintly acidulated with sulphuric acid. Cinchona bark yields from 24% to 30% of aqueous extract. 2. (From PALE BARK :— Extract of pale cinchona , E. of pale bark , E. of lance-leaved b. ; Extractum cinch onæ vallidæ , L.)— a. (Ph. L.) From pale bark, as EXTRACT OF CINCHONA —Ph. L. ( above ). b. (Ph. L. 1836.) From the decoction. Obs. This forms the EXTRACT OF BARK of the shops. The red and yellow cinchona barks are scarcely ever used for making extracts. Their richne in quinine leads to their almost, exclusive employment for the manufacture of that alkaloid, by which their value is greatly enhanced. As far as our knowledge extends, no other extract of bark than this is either employed or asked for. 3. (From RED BARK :— Extract of red cinchona , E. of red bark , E. of oblong-leaved b. ; Extractum cinch onæ rubræ , L.)— a. (Ph. L.) From red bark, as EXTRACT OF CINCHONA —Ph. L. ( above ). b. (Ph. L. 1836.) From the decoction. Obs. These extracts are ordered to be kept in two states, the one ( SOFT EXTRACT OF CINCHONA ; EXTRACTUM CINCHONÆ MOLLE ) for making pills, .; the other ( HARD EXTRACT OF CINCHONA ; EXTRACTUM CINCHONÆ DURUM ) for powdering.—The dose, ., of all the above are the same. 4. (Dry:— E ential salt of bark ; Extractum cinch onæ siccum , L.)— a. (P. Cod.) From an aqueous infusion of pale bark (prepared by displacement with water at a temperature not above 77° Fahr.), evaporated to the consistence of a thick syrup, and then spread thinly and uniformly on earthenware dishes, or sheets of gla , and dried in a stove, by a very gentle heat. It is separated from the plates with a knife, and preserved in well-closed phials. Prior to spreading it out on the plates, about 4% or 5% of thick mucilage is commonly added. b. (Ph. Bor.) As the above (nearly). c. (Ph. Hann. 1831.) Similar to the above; but the liquid, when it acquires the consistence of treacle, is diluted with water, and again evaporated to a like consistence; and this dilution and evaporation is repeated until, on the addition of water, it forms a clear solution.— Dose , 5 to 25 gr. The product of the last formula is nearly inert, and that of the others po e es little activity. 5. (Fluid:— Extractum cinch onæ fluidum , L.)— a. See Liquor of Cinchona . b. (Dr Neligan.) From yellow bark, as FLUID EXTRACT OF BUCHU . 6. (Resinous:— Alcoholic extract of bark ; Extractum cinch onæ alcohol i cum , E. cinch onæ , L.)— a. (Ph. E.) From any variety of cinchona bark (in powder), 4 oz.; proof spirit, 24 fl. oz.; prepare a tincture by displacement, distil off most of the spirit, and evaporate the residuum to the consistence of an extract. This is the only EXTRACTUM CINCHONÆ of the Edinburgh College. b. (Ph. U. S.) Peruvian bark, 1 lb.; rectified spirit, 4 pints; make 4 pints of tincture by displacement; add water to the ma in the percolator, digest, and obtain 6 pints of infusion; distil off the spirit from the tincture, and evaporate the infusion to the consistence of syrup, then mix the two, and complete the evaporation. More active than the aqueous extract.— Dose , 5 to 20 gr. c. (Ellis.) Yellow bark, 2 lbs.; hydrochloric acid, 4 fl. dr.; water, 1 gall.; boil, strain, and repeat the decoction with fresh water and acid; mix the decoctions, filter, and agitate it with fresh-slaked lime, 2 1 ⁄ 2 oz.; filter or decant; dry the residuum, and exhaust it with hot alcohol, q. s.; lastly, evaporate the alcoholic tincture to a pilular consistence.— Dose , 1 to 5 gr. Some persons have proposed to call this ‘ ESSENTIAL SALT OF BARK ,’ 7. (Vinous:— Extractum cinch onæ vinosum , L.—Ph. He e.) Peruvian bark (in powder), 1 part; white wine (sherry), 8 parts; digest 3 days, expre , filter, and evaporate.