Jalap resin is prepared by the following process:—Digest 100 of jalap, in No. 40 powder, with twice its weight of alcohol, for twenty-four hours, at a moderate temperature; then transfer the mixture to a percolator, allow the liquid to pass, and exhaust the drug by percolation with more alcohol; add 50 of distilled water to the percolate, recover the alcohol from the mixture by distillation, allow the residue to cool in an open dish, and dry the resin after washing it repeatedly with hot distilled water. It is also official in the U.S.P. Jalap resin occurs in dark-brown, brittle, opaque fragments, with translucent edges, or as a pale brown powder, with a sweetish odour and acrid taste.
Soluble in alcohol, and partly soluble (about 10 per cent.) in ether; but insoluble in oil of turpentine, and almost or entirely insoluble in warm water.
Action and Uses.—The resin consists chiefly of the two glucosidal resins of jalap, the purified resin containing about 90 per cent. of jalapin and 10 per cent. of scammonin. It has the properties of crude jalap, but in a more concentrated form. It causes evacuation more rapidly than the anthracene purgatives, the stools are watery and profuse, and may be accompanied by considerable pain and tenesmus. Jalap resin is administered in pills, which are best massed with syrup of glucose. The addition of soap facilitates solution of the pill and enhances the action of the drug. It is used with scammony resin in the official compound scammony pill. Oleoresin of ginger is suitable as a carminative, for use with jalap preparations in pill form.
Dose.—1 to 3 decigrams (2 to 5 grains).
- Mistura Jalapae cum Rheo, B.P.C.—JALAP MIXTURE WITH RHUBARB.
- Each fluid drachm contains 1/4 grain of jalap resin, 10 minims of compound tincture of rhubarb, 1/4 grain of tragacanth, 5 minims of syrup of ginger, 10 minims of glycerin, with a sufficient quantity of caraway water. Dose.—4 mils (1 fluid drachm) for a child one year old; or 30 mils (1 fluid ounce) for an adult.
The British Pharmaceutical Codex, 1911, was published by direction of the Council of the Pharmaceutical Society of Great Britain.