PODOLSK, a town of Russia in the province of Moscow, in 27' N., 28' E., 26 m. S. of Moscow, on the railway and on the Pakhra river, crossed by a suspension and a railway bridge. Pop. (1926) 19,335. The town manufactures cement, lime, silicates and silk goods and has a railway repair shop. Until 1781 it was a dependency of the Danilov monastery of Moscow. Near it is an unkept park on the banks of the Pakhra, on the former estate of Count Tolstoi, and a museum, once a house of Prince Golitzin. PODOPHYLLIN, a drug obtained from the rhizome of the American mandrake or May apple (q.v.). As met with in com merce, the rhizome occurs in cylindrical pieces 2 or 3 in. long and about a in. in diameter, of a chocolate or purplish-brown colour, smooth, and slightly enlarged where the juncture of the leafy stem is indicated by a circular scar on the upper and a few broken root lets on the under side. The odour is heavy and disagreeable, and the taste acrid and bitter.
Podophyllin is a resinous powder obtained by precipitating an alcoholic tincture of the rhizome by means of water acidulated with hydrochloric acid. The powder is soluble in alcohol and
strong solutions of alkalis. There are at least two resins in the powder (which is known officially as Podophylli resina), one being soluble and the other insoluble in ether. Each contains an active substance, which can be obtained in crystalline form, and is known as podophyllotoxin. It is soluble in alcohol, ether, chloro form and boiling water. The properties of podophyllin resin vary with the reaction of the tissue with which it is in contact where this is acid the drug is inert, the picro-podophyllin being pre cipitated.
The resin does not affect the unbroken skin, but may be ab sorbed from a raw surface, and will then cause purging. When taken internally it is both a secretory' and an excretory cholagogue. It is largely used in patent medicines, usually as an auxiliary to aloes. The best method of prescribing podophyllin is in pill form. In toxic doses podophyllin causes intense enteritis which may end in death. (See MAY APPLE.)