PENTANE. — Pentane, or amyl-hy dride, is a fluid preparation obtained from coal-tar or petroleum. It occurs as a colorless, inflammable liquid, having a pleasant, fruity odor, and is soluble in alcohol.
Pentane is an hydrocarbon (C5H,2), the fifth in number of the paraffin series.
It was proposed as an anesthetic and is said to act without causing irritation or dyspncea, but it has not been suffi ciently used to insure its recommenda tion.
PEPSIN.—Pepsin (pepsinum, U. S. P.) is a proteolytic ferment obtained from the glandular layer of fresh stomachs from healthy pigs, and capable of digest ing not less than 3000 times its own weight of freshly coagulated and disin tegrated egg-albumin, when combined with 1000 times its weight of a 2-per cent. solution of hydrochloric acid and maintained for six hours at a temperature of not less than 100.4° F. or more than 104° F., the vessel in which it is con tained being gently agitated every fif teen minutes. At the end of the given time little or no residue should be ob served, but a few thin flakes of the co agulated albumin need hardly be re garded. Pepsin occurs in yellowish-white or white scales or in powder, having a slight acid or saline taste and should be free from odor. Much of the commercial pepsin is adulterated or contaminated with peptone, and may also contain mu cus and albumin. The presence of pep tone is manifested by its peculiar musty odor, and, if it be present in large amount, it will absorb moisture and be come sticky when exposed to the air.
Preparations and Doses.—Pcpsinum, U. S. P. (pepsin, 1-3000), 1 to 10 grains.
Pepsinum saccharatum, U. S. P. (sac cliarated pepsin, 1-300), 5 to 30 grains.
Besides the of preparations, there are others on the market which may be preferred. Essence of pepsin (1 to 4 drachms), glycerole of pepsin (V, to 1 drachm), the liquor pepsini, U. S. P..
1SSO (1 to 4 drachms), pepsin cordial (1 to 2 drachms), and wine of pepsin (1 to 4 drachms) are available fluid prepara tions.
Physiological Action and Therapeu tics.—The terms "peptonized" and "pep tone" are so fixed in the popular mind in association with pepsin that many con tinue to regard a peptonized food as one made with or containing pepsin. Pepsin is not available for peptonizing food for the sick in the household. Its action is not only restricted to albuminous (pro teid) substances, but, acid being indis pensable, the product is, for this reason, unsuitable as a food. In the laboratory it may be used and is used, for there the acids are removed and the products are properly clarified. Pepsin is useless in the artificial digestion of milk. Pepsin cannot be used for the artificial digestion of food at the table in the way that pan creatic extract may be.
Pepsin, even in large quantities, has no inhibitory action on lactic-acid fer mentation, and whatever inhibition is exerted by native or artificial gastric juice depends on the hydrochloric acid. Combined hydrochloric acid in large quantities also exerts such an action. Even on other forms of fermentation pepsin has no hindering influence of any importance; at least, none that can be compared with the antibacterial action of hydrochloric acid. L. Aldor (Berliner kiln. Woch., July 25, 'OS).
In using pepsin, or other digestive fer ment, certain points should be observed, lest the ferment become inert before ingestion. A digestive ferment should never be mixed with water or any fluid of a higher temperature than can readily be borne by the mouth. In the pepton izing process, in sprays, in surgical solv ents, too high temperature should be avoided. Pepsin is destroyed in alkaline solutions (with lime-water, sodium bicar bonate, aromatic spirit of ammonia, etc.). All ferments in solution soon decompose unless in the presence of an antiseptic. The ferments should not be mixed un diluted with strong, alcoholic tinctures or astringents. Pancreatic ferments should not be placed in acid mixtures. Pepsin and pancreatic ferments should not be mixed together in solutions, acid or alkaline. These mixed ferments can not be permanently held in an active form in any solution. (Fairchild.) Pepsin is best given with or immedi ately after food (as its digestive action is solely expended upon the proteids, which action takes place at once in the stomach), combined with hydrochloric acid (as the presence of the acid converts any pepsinogen in the gastric tubules into pepsin), as an aid to weak digestion. Pepsin is useful in atonic dyspepsia, espe cially in that present during convales cence from acute diseases. Gastric irri tability is relieved by pepsin combined with bismuth in powder (bismuth in so lution is incompatible with pepsin).
Pepsin is of value in gastralgia, pyrosis, gastric catarrh, and infantile apepsia. In gastric ulcer and in carcinoma of the stomach pepsin relieves the vomiting and assists the impaired digestive organs.
Pepsin is an efficient digestive ferment only in proteid indigestion. It is useless in intestinal indigestion, as it has no solvent action upon fats or starches. As a remedy for indigestion, pepsin is much inferior to pancreatin (pancreatic ex tract) or papain.
In INFANTILE DIARRHEA arising from indigestion pepsin is a useful adjunct to other treatment; essence of pepsin given in doses of 10 to 30 drops immediately after nursing will assist in the digestion of the milk-curds. In this disorder pep tonized milk will give better results than pepsin.