This section is from the book "A Text Book Of Materia Medica, Being An Account Of The More Important Crude Drugs Of Vegetable And Animal Origin", by Henry G. Greenish. Also available from Amazon: A Text Book of Materia Medica : Being an Account of the More Important Crude Drugs of Vegetable and Animal Origin.
Ipecacuanha root is obtained from Psychotria (Cephaleis) Ipecacuanha, Stokes (N.O. Eubiaceoe), a small plant about 30 cm. in height with a stem that is at first prostrate or ascending and afterwards becomes erect. It is found in most parts of Brazil, but especially in the province of Matto Grosso, in the interior, whence much of the drug is obtained; it is also cultivated in the province of Minas Geraes. It is conveyed down the Paraguay and Parana rivers to Montevideo whence it is exported.
Endeavours have not been wanting to cultivate the ipecacuanha plant in other countries, and they have met with some success. From the state of Selangor (near Singapore) ipecacuanha root of unusually fine appearance and rich in alkaloid is exported in considerable quantity. In Java, Ceylon, and China the cultivation has not been successful.
From the slender, prostrate stem fibrous roots are given off at intervals; some of these in the course of their growth develop an abnormally thick bark in which abundance of starch is deposited, whilst the wood remains comparatively small. These thickened roots should constitute the commercial drug; they are collected by raising the plants, which usually form clumps, from the earth, removing the roots, drying them, and sifting them from adherent sand and earth. The drug is exported in compact canvas bales. Very frequently much of the prostrate or ascending stem finds its way into the drug.
Ipecacuanha appears to have long been used in Brazil for dysentery; it was introduced into Europe about 1672.
The official ipecacuanha root, which is distinguished as Brazilian or Rio ipecacuanha, is slender and rather tortuous, seldom exceeding, in the commercial drug, 15 cm. in length or 5 mm. in thickness. The colour varies from dark brick-red to dark brown, the former being due, partly at least, to adhering particles of earth. Very characteristic of the root is the annulated appearance that it presents, the bark of typical pieces being constricted at short intervals so as to resemble a number of discs somewhat irregularly strung together; the constrictions are sometimes quite shallow, but sometimes they penetrate nearly to the wood. These annulations seldom, however, take the form of distinct, rather distant, narrow, raised ridges (compare Cartagena ipecacuanha).
Fig. 165. - A, Brazilian Ipecacuanha (P. Ipecacuanha) cultivated in Selangor. B, Cartagena Ipecacuanha. Large specimens. Natural size.
The root is hard and breaks with a very short fracture. The transverse section exhibits a thick, dark grey bark which is usually horny, but sometimes starchy, and a small wood in which no distinct pores or pith can be discerned when examined with a lens. The bark, when examined under the microscope, is found to contain abundance of starch grains that are mostly compound and, in addition, acicular crystals of calcium oxalate; the wood is free from vessels. These characters are useful in distinguishing ipecacuanha from certain substitutes that appear from time to time, and are referred to below.
The drug has a slight odour which to many persons is particularly unpleasant; the taste is slightly bitter. The powder is often very irritating to the throat and nostrils, producing violent coughing and sneezing.
The student should observe
(a) The closely approximated disc-like annulations,
(b) The thick, starchy bark,
(c) The small, dense wood; and should compare this variety with Cartagena ipecacuanha, which is usually rather thicker, and in which the annulations assume the form of distinct, somewhat distant, narrow, raised ridges.
Below the narrow cork is a largely developed cortex consisting of thin-walled parenchymatous cells most of which are filled with starch, but a few contain acicular calcium oxalate. The bast ring is narrow, and both this and the cortex are free from sclerenchymatous cells and fibres and from cells containing colouring matter. The wood is composed of tracheids, wood fibres, and parenchyma and is free from typical vessels. The tracheids, when isolated, exhibit moderately thick walls, and often near the pointed extremities a large perforation.
The powder is characterised by the starch grains which are either oval or rounded (not over 15µ) or compound with from 2 to 5 constituent grains, by the acicular calcium oxalate, by the characteristic tracheids and by the absence of sclerenchymatous cells, spiral vessels (ipecacuanha stem), cells containing colouring water, calcium oxalate in other than acicular crystals, and typical sclerenchymatous fibres or vessels.
Ipecacuanha root contains three alkaloids; two of which, emetine and cephaeline, have been more closely examined, whilst the third, psychotrine, which occurs in much smaller quantity, awaits further investigation. These alkaloids exist in good root to the extent of from 2 to 3 per cent., and are contained chiefly in the bark, the wood yielding only about 1 per cent. The alkaloids ipecamine and hydroipecamine have also been reported as present.
Fig. 166. - True Ipecacuanha (Psy-chotria Ipecacuanha). Transverse section, showing dense wood. Magnified. (Planchon and Collin).
Ipecacuanha also contains about 0.4 per cent, of a crystalline glucoside, ipecacuanhin, which is sparingly soluble in cold water, more freely in hot, insoluble in ether; it is apparently devoid of marked physiological action.