275. Pilocarpus. Jaborandi.
BOTANICAL CHARACTERISTICS.—A shrub 4 to 5 feet high. Leaflets 1 to 4 pairs, petiolate. Flowers in long racemes. Ovary with 5 carpels. Seeds black, angular.
SOURCE, VARIETIES, AND ADULTERATIONS.—The name Jaborandi is a generic one, applied in South America to several plants possessing diaphoretic properties. The shrub, Pilocarpus jaborandi, grows in Brazil in the neighborhood of Pernambuco, known commercially as Pernambuco Jaborandi. P. microphyllus (which yields a large percentage of alkaloid), differs from this in absence of oil from their tissues, by their reticulated venation, etc., is known commercially as Maranham jaborandi. It has been adulterated with species of Piper, which are not pellucid-punctate, with Laurus nobilis, etc.
DESCRIPTION OF DRUG.—Leaves nearly sessile, pinnate, with a terminal leaflet; the leaflets, which come into market separate, are ovate-oblong, entire, about 100 mm. (4 in.) long, and 50 mm. (2 in.) broad; short-petiolate; uneven at the base; slightly revolute at margin, near which the anastomosing veins form one or two distinct wavy lines; coriaceous; dull green, finely marked with small, transparent dots or oil-cells, plainly visible when held up to the light; texture coriaceous, brittle; when bruised a peculiar, rather unpleasant odor is emitted; this odor is predominant in the fluidextract. Taste disagreeable, slightly pungent, and bitter. The leaflets of P. microphyllus (Maranham jaborandi) are smaller (2-5 to 4 cm. in length), usually ovate in outline, deeply emarginate at apex. Alkaloidal content (chiefly Pilocarpine) of best leaf ranges from 0.5 to 1 per cent.
Powder.—Yellowish-brown. Characteristic elements: See Part iv, Chap. I, B.
CONSTITUENTS.—A volatile oil, and two alkaloids, pilocarpine (C11H17N2O2), deliquescent, crystalline, inodorous, and slightly bitter, and jaborine, chemically isomeric with, but directly antagonistic to, the first named in physiological action. Pilocarpine is the most active, and yields jaborine and pilocarpidine (C10H14N2O2) when heated with HCl; its salts are readily soluble in water; their action is similar to that of nicotine. Jaborine (C22H32N4O4) is yellow, amorphous, and resembles atropine in action; its presence in the commercial pilocarpine explains the different effects following the use of the latter when improperly made. It is therefore very necessary, in using pilocarpine or any of its preparations, to obtain them free from jaborine.
Preparation of Pilocarpine.—To an aqueous solution of acidulated alcoholic extract add alkali and shake with chloroform. From the chloroformic solution the alkaloid is separated by shaking with acidulated (HCl) water, filter, and allow it to crystallize.
ACTION AND USES.—Powerfully diaphoretic and sialagogue by stimulating the nerves supplying the glands and involuntary muscular fiber; cardiac depressant. The most important effects of pilocarpine are due to the stimulation of certain nerve terminations. It stimulates the peripheral endings of all the autonomous nerves. The most important effect of the ingestion of a therapeutic dose of pilocarpine is an increase in the secretory activity of nearly all the glands of the body, especially of the salivary and sweat-glands. Dose: of drug 5 to 60 gr. (0.3 to 4 Gm.). Pilocarpine is used as a myotic in ophthalmic practice. It has acquired some reputation in the treatment of diphtheria and croup; frequently administered hypodermically; poisonous. Dose of pilocarpinae hydrochloridum, 1/8 to 1/12 gr. (0.008 to 0.005 Gm.). Ash, not exceeding 7 per cent.
Fluidextractum Pilocarpi, Dose: 5 to 60 drops (0.3 to 4 mils).