Styrax. U. S. (Br.) Storax [Liquid Storax]

Related entry: Liquidambar

"A balsam obtained from the wood and inner bark of Liquidambar orientalis Miller (Fam. Hamamelidaceae)." U. S. "Prepared Storax is a viscid balsam obtained from the wounded trunk of Liquidambar orientalis, Mill., purified by solution in alcohol, filtration, and evaporation of the solvent." Br.

Styrax Praeparatus, Br.; Prepared Storax; Styrax Liquidus, Balsamum Storacis, Balsamum Styracis, Balsamum Styrax Liquidua; Styrax liquide, Fr. Cod.; Styrax, P. G.; Storax, Flüssiger Storas, G.; Storace liquido. It.; Estoraque liquido, Sp.

All species of the genus Liquidambar as well as those of a related genus, Altingia, yield storax. The product most valued, however, is that obtained from L. orientalis Miller.

The oriental sweet-gum (Liquidambar orientalis) is a tree from twenty to forty feet high. The palmate leaves have each of their divisions obscurely three-lobed, and are serrate, perfectly smooth, bright green and shining on the upper and pale on the under surface. The tree is a native of Asia Minor, in the southwestern parts of which it forms large forests. It yields the so-called liquid storax.

According to the researches of Moeller, storax is a pathological rather than a physiological product; when the young wood is injured secretion reservoirs are formed in which the storax is produced. (O. Z., 1.) In collecting the drug the outer bark is first heavily bruised, so as to injure the inner bark, and after a time the outer bark having been removed the inner bark is scraped off. According to Maltass, this inner bark is first pressed cold in horse-hair bag's, after which hot water is thrown over the bags and they are again pressed. Lieutenant Campbell states that the inner bark is first boiled with water, and, a portion of the balsam which rises having been skimmed off, is then pressed so as to extract the remainder. The residuary bark, after expression, is dried in the sun, and employed in various parts of Turkey for fumigation. It is the drug known in commerce as Storax bark or Cortex Thymiamatis. (Hanbury, P. J., 1857, xvi, 463.) The balsam is sent in casks to Constantinople, Smyrna, and other ports of the Levant.

Several kinds of storax have been described. The purest was the storax in grains, which was in whitish, yellowish-white, or reddish-yellow tears, about the size of a pea, opaque, soft, adhesive, and capable of uniting so as to form a mass. Another variety, formerly called styrax calamita, from the circumstance, it is supposed, that it was brought wrapped in the leaves of a kind of reed, consisted of dry and brittle masses, formed of yellowish agglutinated tears, in the interstices of which was a brown or reddish matter. The French call it storax amygdaloide. This and the preceding variety had a pleasant odor like that of vanilla. Neither of them, however, is now found in the markets. It is probable that one or both of these varieties may have been the product of Styrax officinale. A third variety, which was formerly seen in commerce, styrax calamita, was in brown or reddish-brown masses of various shapes, light, friable, yet possessing a certain degree of tenacity, and softening under the teeth. Upon exposure, it becomes covered upon the surface with a white efflorescence of styracin. It evidently consisted of sawdust, united with a portion of the balsam. As found in commerce, it was usually in the state of a coarse, soft, dark-colored powder, mingled with occasional light friable lumps of various sizes, and containing very little of the balsam. When good, it should yield, upon pressure between hot plates, a brown resinous fluid having the odor of storax. Hanbury states that some of this variety is prepared at Trieste, Venice, and Marseilles, by mixing the residue of the liquidambar bark remaining after expression, and reduced to coarse powder, with genuine liquid storax. (P. J., April, 1863.)

American Storax, Liquidambar styracifiua, or Sweet Gum of our Southern States.—Its geographical range reaches into Mexico, and it yields a storax-like product in an abundance proportionate to the heat of the climate. A specimen from Guatemala is described by Flückiger and Hanbury as a yellow, opaque resin, of honey-like consistence, becoming transparent, amber-colored, and brittle by exposure to the air, and having a rather terebinthinous balsamic odor and but little taste. Sometimes it occurs as a thick golden-brown fluid. It contains cinnamic acid and stryacin. (A. J. P., 1874, p. 161.) It is soluble in alcohol, and has been gathered to a considerable extent in the United States for the preparation of chewing gum. The resins of Liquidambar formosana and L. altigiana are known in Eastern commerce. Malay storax is an aromatic resinous product obtained from the Altingia excelsa Noronha (L. altigiana Bl.) It is sometimes called rasamala resin and contains tannic acid besides a very minute amount of cinnamic and benzoic acids.

A fourth variety, which, under the name of liquid storax, is the one commonly used, is a semi-fluid, adhesive substance, brown or almost black upon the surface exposed to the air, but of a slightly greenish-gray color within, and of an odor somewhat like that of balsam of Peru, though less agreeable. It is kept in jars.

Properties.—The storax used by pharmacists should correspond to the following official description and tests: "Storax is a semi-liquid, grayish, sticky, opaque mass, depositing" on standing a heavy, dark brown stratum; transparent in thin layers, and having a characteristic odor and an acrid taste. It is heavier than water. It is insoluble in water, but completely soluble (with the exception of accidental impurities) in an equal weight of warm alcohol; almost completely soluble in ether, acetone, benzene, or carbon disulphide. When heated on a water-bath, Storax becomes more fluid, and if it is then agitated with warm, purified petroleum benzin, the supernatant liquid, on being decanted and allowed to cool, is not darker than pale yellow and deposits white crystals of cinnamic acid and cinnamic esters. The separated crystals evolve the odor of benzaldehyde when heated with diluted sulphuric acid and potassium permanganate. Incinerate about 0.5 Gm. of Storax; not more than 1 per cent. of ash remains. Dissolve about 10 Gm. of Storax, accurately weighed, in 20 mils of hot alcohol; the undissolved residue, after washing it on a filter with hot alcohol and drying at 100° C. (212° F.), does not exceed 2.5 per cent. The combined filtrate and washings, after the evaporation of the alcohol at a temperature not exceeding 60° C. (140° F.) and drying the residue for one hour at 100° C. (212° F.), leave a brown, transparent, semi-liquid product representing not less than 60 per cent. of the weight of Storax taken; this product is soluble in ether, with the exception of a few flakes, but only partially soluble in purified petroleum benzin. Dissolve about 1 Gm. of Storax, purified as described above, and accurately weighed, in 50 mils of alcohol, add 0.5 mil of phenolphthalein T.S., and titrate with half-normal alcoholic potassium hydroxide V.S. The acid value so obtained is not less than 56 nor more than 85 (see Part III, Test No. 10). Mix about 1 Gm. of Storax, purified as described, and accurately weighed, in a 250 mil flask with 50 mils of purified petroleum benzin, add 25 mils of half-normal alcoholic potassium hydroxide V.S. and allow the mixture to stand twenty-four hours, with frequent shaking. Then add 0.5 mil of phenolphthalein T.S. and titrate with half-normal hydrochloric acid V.S. It shows a saponification value of not less than 170 nor more than 230 (see Part III, Test No. 9)." U. S.

As found in commerce, storax is usually so much adulterated as to require purification before it can be used, and in both Pharmacopoeias processes were formerly given. Whenever not originally pure enough for use, it should be dissolved in alcohol, the solution strained, and the alcohol distilled off to a certain extent, and then completely evaporated at a gentle heat. Among the substances used in the adulteration of storax is turpentine. To detect it Hager employed the following method. He liquefied the resin, in a tube, by means of a water bath, added half its volume of absolute alcohol, and hastened the solution by agitation; he then treated it with several volumes of benzin. This operation was repeated twice. The liquors obtained were then evaporated, in a tared vessel, and there was secured, for pure storax, a colorless residue (45 to 55 per cent.), with a light-blue opalescence; for that mixed with turpentine, a residue more considerable, yellowish, and having the terebinthinate odor. (J. P. C., Fev., 1876, p. 161.) The quality of storax at present on the market appears to be very much inferior to what it was a few years ago. It is stated (P. J., 1911, lxxxvii, p. 86) that whereas in 1907 the commercial storax averaged about 19 per cent. of cinnamic acid with an acid number of 68.9, that upon the market in 1911 contained only about 2.5 per cent. of cinnamic acid, and had an acid number around 100. It is not improbable that this deterioration is due to the extraction of cinnamic acid before it is marketed.

Storax melts with a moderate heat, and, when the temperature is raised, takes fire and burns with a white flame, leaving a light, spongy, carbonaceous residue. It imparts its odor to water, which it renders yellow and milky. Its active constituents are dissolved by alcohol and ether. Neumann obtained from 480 grains of storax 120 of aqueous extract, and from an equal quantity 360 grains of alcoholic extract. Containing volatile oil and resin, and yielding benzoic or cinnamic acid by distillation, it is entitled to rank as a balsam.

The most abundant constituent of storax is probably storesin, C36H55(OH)3, discovered in 1877 by W. von Miller. This is present in two forms, designated respectively alpha and beta, both free and in the form of a cinnamic ester. Storesin is an amorphous substance, melting at 168° C. (334.4° F.), readily soluble in petroleum benzin. Cinnamic esters of phenylpropyl, cinnamic ester of ethyl, cinnamic ester of benzyl, and especially cinnamate of cinnamyl, C9H7O2.C9H9, the so-called styracin of Bonastre, have also been observed. This last compound can be removed by ether, benzene, or alcohol after the separation from the resin of the cinnamic acid; it is insoluble in water, and volatile only in superheated steam. It crystallizes in tufts of long rectangular prisms, which melt at 38° C. (100.4° F.), but frequently do not solidify readily. By concentrated solution of potassium hydroxide, it is resolved into a cinnamate and cinnamic alcohol (styrone), C9H10O, which latter is not present in liquid storax. The yield of cinnamic acid varies from 6 to 12 per cent., or even, according to Lowe, as much as 23 per cent. of crystallized cinnamic acid can be obtained. The acid dissolves abundantly in ether, alcohol, or hot water, slightly in cold watery it is inodorous, but has an acrid taste. It fuses at 133° C. (271.4° F.), and boils at 290° C. (554° F.). Another minor constituent of storax is a fragrant substance melting at 65° C. (149° F.), and possessing the odor of vanillin, which Rump (Ber. d. Chem. Ges., 1878, 1034) identified. Miller also shows that water removes from the drug a little free benzoic acid. There is further found in liquid storax a hydrocarbon, C8H8, first prepared by Simon in 1839, which exists in the resin as a liquid, and also in a polymeric form as a solid. The former, called styrol, styrene, or cinnamene styrene, has a sp. gr. of 0.924, and a boiling point of 146° C. (294.8° F.). It is a colorless, mobile liquid, possessing the odor and burning taste of liquid storax. It has since been formed synthetically, and has been recognized as phenylethylene, C6H5.CH=CH2. When heated for a considerable time to 100° C. (212° F.), or for a shorter period to 200° C. (392° F.), it is converted without change of composition into the colorless, transparent solid metastyrol, which, unlike styrol, is not, soluble in alcohol or in ether. Lastly, there has been found in liquid storax, by J. H. van t'Hoff (1876), about 0.4 per cent. of a pleasant-smelling laevo-rotatory oil of the formula C10H16O. (Pharmacographia, 2d ed., 274 and 275.) Tschirch and L. v. Itallie (A. Pharm., Sept., 1901, 506) state that styrax contains free cinnamic acid, vanillin, styrol, styracin, cinnamic acid-ethyl ester, cinnamic acid-phenyl-propyi ester and storesinol partly free and partly as cinnamic acid ester.

Uses.—Styrax is a stimulating expectorant and feeble antiseptic, which was at one time used in various pulmonic catarrhs, also in gonorrhea and leucorrhea, but at present is very seldom used except as a constituent of the compound tincture of benzoin. Externally, mixed with two or three parts of olive oil, liquid storax was found by H. Schultze, of Magdeburg, to be very effective as a local remedy in scabies.

Dose, ten to twenty grains (0.65-1.3 Gm.).

Off. Prep.—Tinctura Benzoini Composita, U. S., Br.

The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.