This section is from the "A Handbook of Useful Drugs" book, by State Medical Examining and Licensing Boards.
Properties : Bismuth subsalicylate occurs as a white or nearly white amorphous crystalline powder, odorless and tasteless. It is practically insoluble in cold water; on prolonged boiling with water a portion of the salicylic acid passes into solution with the formation of a more basic bismuth salicylate.
Incompatibilities: It is decomposed by hydrochloric acid or nitric acid: a more basic insoluble compound remaining. Alcohol also decomposes bismuth subsalicylate with accompanying solution of the liberated salicylic acid. The compound is also incompatible with alkali carbonates and bicarbonates, tannin and salts of iron.
Action and Uses: Bismuth subsalicylate, like other salts of bismuth, is protective and astringent; it has also been recommended to some extent as an intestinal anti-septic. Because of the ease with which it is decomposed it is best prescribed in the form of powders, capsules or cachets.
Dosage: 0.25 gm. or 4 grains.