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..
C6H4(OH)2=109.74. Synonyms. - Resorcinol. Meta-dioxy benzol.
This is a diatomic phenol obtained by heating Benzene with fuming Sulphuric Acid, whereby Benzene Metadisulphonic Acid is formed (C6H4(Hso3)2). The acid is dissolved in water, neutralized with Milk of Lime, the Calcium Sulphate expressed, Sodium Carbonate added, filtered and the filtrate evaporated to dryness. The residue is then heated with Caustic Soda and Sodium Resorcin (C6H4(ONa)2) is formed; continuous boiling expels the Sulphurous Acid, and the residue is extracted with Ether and impure Resorcin obtained by distillation. This is purified by sublimation or re-crystallization from water.
Colorless or faintly reddish, needle-shaped crystals or rhombic plates, having a faint, peculiar odor, and a disagreeable, sweetish and afterwards pungent taste, acquiring a reddish or brownish tint by exposure to light and air. Solubility. - In 0.6 part of water, and in 0.5 part of Alcohol; also readily soluble in Ether or Glycerin; very slightly soluble in Chloroform.
Dose, 2 to 5 gr.; .12 to .30 gm.
This substance, originally introduced as an antipyretic, is now rarely employed for this purpose, as the necessarily large doses are too depressant to the heart. A solution of resorcin in glycerin, 1 to 4, is excellent for removing epidermic scales in chronic skin diseases, and also for getting rid of the scales in seborrhoea sicca of the scalp; here it doubtless inhibits the action of the bacteria which may be the cause of dandruff. A lotion: Resorcin, 1; ether, 1; castor oil, 1; eau de cologne, 10; alcohol (90 per cent.), 35; is useful for dandruff and alopecia. Resorcin is a powerful antiseptic, and a 5 per cent. solution may be injected into the bladder in cystitis. It is of great value in fermentative dyspepsia when administered, well diluted, one hour after ingestion of food. Dark-colored urine, often described as smoky, is sometimes seen after large doses.