This section is from the book "Materia Medica Pharmacy, Pharmacology And Therapeutics", by W. Hale White. Also available from Amazon: Materia Medica Pharmacy, Pharmacology And Therapeutics..
The root of Rheum officinale Baillon (nat. ord. Poly-gonaceae).
Western and Central China.
In cylindrical, conical or flattish segments, deprived of the dark brown, corky layer, smoothish or somewhat wrinkled, externally covered with a bright yellowish-brown powder, marked with white, elongated meshes, containing a white, rather spongy tissue, and a number of short reddish-brown or brownish-yellow striae; compact, hard; fracture uneven; internally white, with numerous red, irregularly curved and interrupted medullary rays, which are radially parallel only near the cambium line; odor somewhat peculiar. aromatic; taste bitter, somewhat astringent.
The chief constituents are - (1) Chrysophan, C27H30O14, which yields Chrysophanic Acid, C15H10O4, about 3 per cent. Synonyms. - Rhein. Chrysarobin, see Chrysarobinum. It is not known whether, in the living plant, Rhubarb contains any Chrysophanic Acid, for when kept the Chrysophan quickly oxidizes to Chrysophanic Acid. The purgative properties are due to Ghrysophan which also gives the yellow color. (2) Erythroretin. (3) Emodin. (4) Phaeoretin. (5) Aporetin. (6) Rheotannic Acid,C26H26O14, to which the astringency of Rhubarb is due. (7) Lime Oxalate, 35 per cent., to which the grittiness is due.
Dose, 1 to 5 gr.; .06 to .30 gm. (stomachic); 10 to 30 gr.; .60 to 2.00 gm. (purgative).
Dose, 3 to 5 gr.; .20 to 1.00 gm.
2. Extractum Rhei Fluidum. - Fluid Extract of Rhubarb. By maceration and percolation with Alcohol and Water, and evaporation. Fluid Extract of Rhubarb is used to make Mistura Rhei et Sodae and Syrupus Rhei.
Dose, 1/4 to 1 fl. dr.; 1. to 4. c.c.
3. Pilulae Rhei. - Pills of Rhubarb. Rhubarb, 20; Soap, 6 gm., to make 100 pills. Each pill contains 3 gr.; .20 gm. of Rhubarb.
Dose, 3 to 5 pills.
4. Pilulae Rhei Compositae. - Compound Pills of Rhubarb. Rhubarb, 13; Purified Aloes, 10; Myrrh, 6 gm.; Oil of Peppermint, 0.5 c.c., to make 100 pills. Each pill contains 2 gr.; . 13 gm. of Rhubarb. Dose, 1 to 3 pills.
5. Pulvis Rhei Compositus. - Compound Powder of Rhubarb. Synonym. - Gregory's powder. Rhubarb, 25; Magnesia, 65; Ginger, 10.
Dose, 1/2 to 1 dr.; 2. to 4. gm.
Dose, 1/2 to 1 fl. dr.; 2. to 4. c.c. (stomachic); 1 to 4 fl. dr.; 4. to 15. c.c. (purgative).
Aromatic Tincture of Rhubarb is used to make Syrupus Rhei Aro-maticus.
Dose, 1 to 3 fl. dr.; 4. to 12. c.c.
Dose, 1/2 to 1 fl. oz.; 15. to 30. c.c.
9. Mistura Rhei et Sodae. - Mixture of Rhubarb and Soda. Sodium Bicarbonate, 35; Fluid Extract of Rhubarb, 15; Fluid Extract of Ipecac, 3; Spirit of Peppermint, 25; Glycerin, 350; Water to 1000. By solution.
Dose, 1/4 to 2 fl. oz.; 8. to 60. c.c.
10. Syrupus Rhei. - Syrup of Rhubarb. Fluid Extract of Rhubarb, 100; Potassium Carbonate, 10; Spirit of Cinnamon, 4; Glycerin, 50; Water and Syrup to 1000. By solution.
Dose, 1 to 4 fl. dr.; 4. to 15. c.c.
11. Syrupus Rhei Aromaticus. - Aromatic Syrup of Rhubarb. Aromatic Tincture of Rhubarb, 150; Syrup, 850. By mixture.
Dose, 1 fl. dr.; 4. c.c. for a child.