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..
A neutral principle obtained from several varieties of Aloes, chiefly Barbadoes Aloes (yielding Barbaloin) and Socotrine Aloes (yielding Soca/oin), - differing more or less in chemical composition and physical properties according to the source from which it is derived. Besides these varieties we have Nataloin (Natal) and Zanaloin (Zanzibar).
Soca/oin, C15H16O7, is soluble in about 60 parts of water, 30 parts of absolute Alcohol, 380 parts of Ether, or 9 parts of Acetic Ether.
Minute, acicular crystals, or a microcrystalline powder, varying in color from yellow to yellowish-brown, odorless or possessing a slight odor of Aloes, a characteristic bitter taste, and permanent in the air.
Dose, 1/2 to 2 gr.; .03 to .12 gm.
Aloes has no external action on the unbroken skin, but it can be absorbed from a raw surface, for aloes sprinkled on an ulcer, to which it is a slight stimulant, will lead to purging.
Gastro-intestinal tract. - In the stomach the bitter principle of aloes causes it to act as a stomachic, like other bitters. In the intestine it increases the rate of the flow of bile, and probably the amount secreted. It produces little influence in the small intestine, but the muscular coat of the colon is powerfully stimulated, and the intestinal secretion from that part slightly accelerated. Aloes, therefore, purges, and naturally takes some time, usually fifteen to twenty hours, to act; the motion is well formed, not very soft, as there is so little increased secretion of fluid, and it is dark colored from the bile in it. Sometimes the drug gripes somewhat, because the muscular contraction it produces is irregular. As it acts chiefly on the lower bowel the habitual use of it may lead to piles.
Female genital organs. - Aloes will aggravate the menstrual flow; it is therefore an emmenagogue. It is excreted by the milk, for aloes given to the mother may purge the child. It is stated also to be excreted in the urine, and it is quite likely that the habitual use of aloes will result in irritation of the kidneys.
Barbadoes aloes is more purgative than Socatrine aloes, and contains a greater proportion of substances soluble in water. As a rule aloin acts like aloes, but it does not gripe so much. Some specimens, however, have very little action. This may be owing to adulteration, or differences in composition of different specimens.
Aloes is an excellent purgative for cases of habitual constipation, many of which are due to an imperfect contraction of the muscular coat of the large intestine. It is very commonly given as a dinner pill (1 gr.; .06 gm., of extract of aloes and 1/4 gr.; .015 gm., of extract of nux vomica) to sufferers from chronic constipation, and in these cases its bitter principles acting as stomachics aid digestion. If the faeces are hard, 1/2 gr. .03 gm. of powdered ipecacuanha should be added. To avoid griping it is well to combine a little extract of hyoscyamus or a little extract of belladonna with it. One great advantage of aloes is that the dose need not be gradually increased. It is also very commonly given as a pill with nux vomica and a grain or two; .06 or .12 gm. of dried ferrous sulphate to persons suffering from chlorosis and other forms of anaemia. It overcomes the chronic constipation so common in these cases, and some regard this as very important for the cure of the disease. The amenorrhoea so frequently associated with chlorosis is often benefited by aloes, and amenorrhoea due to other causes may also be relieved. Aloes is of great service in many cases of chronic constipation of children. A warm aqueous solution of aloin purges when injected subcutaneously. Aloes must not be given in pregnancy or menorrhagia. If a patient suffers from haemorrhoids which are not inflamed, aloes can be safely administered, and even with marked benefit if they are due to a relaxed rectal mucous membrane, (Barker). An enema Soco-trine aloes, 8; potassium carbonate, 3; mucilage of starch, 960. is anthelmintic.