Nitroglycerin

NITROGLYCERIN, Nitroglycerinum (synonyms: Glycerinum trinitricum, Trinitrin, Trinitroglycerinum, Glonoin, Angioneurosin), C₃H₅(O.N0₂)_a, is a complete nitric acid ether of glycerin and represents a transparent, colorless or slightly yellowish oily liquid without odor, sweet taste, resembling the taste of glycerin; specific gravity 1.601 at 15°. It is very slightly soluble (1 : 800) in water, well (1 : 4) in absolute alcohol and in all proportions in ether, chloroform, and acetic acid; it is slightly soluble in essential oils and almost insoluble in glycerin. Upon heating (to 200°), impact, or shaking, it gives an extremely powerful explosion. Dynamite is a mixture of N. with infusorial earth. Explosive gelatin represents a mixture of N. with nitrocellulose. Below 8° N. solidifies into long needles and then explodes even more easily than liquid N. Spontaneous explosion may occur with insufficient purity of N. Alkalis easily convert N. into a mixture of nitrates and nitrites. N. is obtained by the careful action of nitric acid on glycerin in the presence of sulfuric acid at cooling. Action on the organism. Locally N. exerts a slight irritating action. By mucous membranes and skin (vapors) N. is easily absorbed in undecomposed form. Having reached the blood, N. decomposes into glycerin, nitrates, and nitrites; the action on the organism can hardly be attributed exclusively to the latter, as was accepted earlier, since the possibility is not excluded that organic nitrates (N., Erythrolum tetranitricum, Mannitolum hexanitricum) may act with the whole molecule, since when passing solutions of them through the vessels of isolated organs the action is obtained very quickly, with intravenous administration the drop in blood pressure to a certain level is achieved by a dose of N. 100 times smaller than the corresponding dose of nitrous acid sodium (Marshall), headache in man is observed much more often with N. than with nitrites. Introduced in small doses, N. is excreted in urine mainly in the form of nitrites, while with large doses a part is also in unchanged form. The absorptive action of N. is in the main similar to that of amyl nitrite (see): administration of N. causes dilation of the vessels of the face and upper half of the body, acceleration of the pulse, drop in blood pressure, noise in the ears; with large doses oxy-Hb of the blood turns into met-Hb; sometimes glycosuria is observed. N. differs from amyl nitrite only in quantitative relations: its action is less strong, begins later (approximately ten minutes after oral intake), lasts longer (2-3 hours), much more often accompanied by severe headache; with poisoning by N. clonic convulsions are observed more often, formation of met-Hb in the blood occurs not so quickly. Despite the great toxicity of N., it is easily (often in 2-3 days) habituation occurs upon repeated application; cessation of N. intake for several days restores the organism's former sensitivity to it. - Acute poisoning by N. is of interest not only in toxicology but also in professional pathology (inhalation of dynamite dust), since N. is used as an explosive substance. Symptoms: nausea, vomiting, colics, sometimes bloody diarrhea, severe headache; with large doses - slowed, dicrotic and irregular pulse, cold and cyanotic skin, clonic convulsions, marked slowing of respiration, death in coma (through 4-7 hours) from paralysis of the respiratory center. The lethal dose of nitroglycerin varies greatly. Stewart reported a patient in whom 1.2 g of N. produced only a slight action. - Treatment of poisoning: washing out the stomach, saline (not oily) laxatives, then drinking of linseed seed decoction, strong black coffee, subcutaneous caffeine, camphor, rubbing of the skin with mustard alcohol, ice on the head, in case of necessity - artificial respiration, bleeding. One can also recommend subcutaneous injections of adrenaline due to its antagonistic action on the vessels. - N. is applied in the same cases as amyl nitrite; besides this it is given in hypertension in the pre-sclerotic state, prophylactically and therapeutically - in the presence of angina pectoris (see). Some caution is required in cases of far advanced degeneration of the cardiac muscle. Due to the strong explosiveness of dry N., it is applied mainly in alcoholic solution or in tablets. It is well tolerated by the gastrointestinal tract. Preparations: 1. Nitroglycerinum solutum (PhVII), seu Spiritus Glycerini trinitrici, a clear colorless 1% solution of pure N. in alcohol. Maximum doses per dose 0.1, per day 0.3, which corresponds to 0.001-0.003 pure nitroglycerin (Ph VII). In angina pectoris one begins to give with very small doses (1-2 drops per dose) and gradually increases to 10 drops per day. Treatment can be interrupted for several days every 2-3 weeks, after which it is given again, starting with a small dose. It is convenient to take on a piece of sugar or with the nail of the big toe. Sometimes it is prescribed with water, e.g. Rp. Nitroglycerini soluti 2.0, Aquae dest. ad 150.0. M. D. S. by dessert or tablespoon 2-3 times a day. It is rarely applied subcutaneously (2-6 drops per day). N. should be handled with caution, since an explosion may occur if a more significant amount of N. is spilled and the alcohol evaporates completely or partially. 2. Tablettae Nitroglycerini; in each tablet 0.5 mg of N. Maximum dose (PhTP): per dose 2 tablets, per day 6 tablets. A practically convenient form, but there are indications of easy changeability of N. in this form. One begins with giving 1 tablet orally, and then gradually increases the dose. Some authors (Ingalls and Meeker; 1918) prefer to give the tablet under the tongue, then the action sets in through 1-3 minutes. If there is no action, then the dose is repeated every few minutes. 3. Klimosan, a calcium preparation with N. Dose - 0.5 per dose. 4. Neur o sin, a mixture of N. with caffeine in tablet form (do not confuse the name with the French preparation Neuro-sin Prunier, containing only Calcium glycerophosphoricum).

M. Nikolaev. N. in the production of explosive substances - fulminating paste and dynamite. Basic processes: 1) preparation of materials (glycerin, acids, colloidal cotton, kieselguhr, wood flour, ammonium nitrate), 2) mixing of acids, 3) nitrating glycerin, 4) separation of N. from the acid mixture, 5) washing, 6) filtering, 7) denitrating of spent acids, 8) conversion of N. into fulminating paste and dynamite. The most harmful and dangerous processes are mixing acids, nitrating glycerin, denitrating acids; oxides of nitrogen are formed in significant quantities during them, which although are removed from the place of formation, but sometimes with non-observance of necessary measures can get into the working premises. Manipulations with N., during which there is a danger of contact with it and inhalation of its vapors, can cause a number of pathological phenomena in workers. In the first days of work strong headache is observed in them, which soon disappears; if a worker ceases work with N. and then resumes it, headaches recur. Further, workers noted a state of anxiety, insomnia, night diarrhea and vomiting, etc. In workers engaged in mixing and sifting dynamite, poorly healing ulcers form under the nails and at the ends of the fingers; often on the palms and on the skin between the fingers of the hands a rash develops, similar to large-scaly psoriasis, with strong dryness of the skin and formation of cracks. In persons who inhaled significant quantities of N. during explosions, trembling, rushes of blood to the head, vomiting, dizziness, headaches, asphyxia, cyanosis, loss of consciousness, coldness of the skin, weak pulse, etc. appear; in severe cases poisoning can end in death. With chronic poisoning by gases formed during explosions (mining), gastrointestinal disorders, trembling, neuralgias, etc. develop.

H. Rosenbaum. NITROSO COMPOUNDS are characterized by the presence of the NO group replacing hydrogen. The greatest number of representatives of nitroso compounds is known in the aromatic series. N. can be obtained by oxidation of amines, hydroxylamines, electrolytic reduction of nitro compounds: C₆H₅. NH₂ + 0₂ = C₆H₅. NO + H₂0; C_eH₅.NH.OH + 0 = C₆H₅.NO + H₂0; C₆H₅. . N0₂ + H₂ = C₅H₆.NO + H₂0. - Nitrosobenzols are crystalline substances; in the solid state they are colorless, possess double molecular weight; in the molten state they are green in color and monomeric. N. with amines form azo compounds: C₆H₅. .N0 + C₆H₅.NH₂ = C_eH₅.N:N.C₆H₅ + H₂0. On oxidation they give nitro compounds, on reduction - amines: C₆H₅ N0 + 0 = C₆H₅. .N0₂; C_eH₅.NO+2H₂=C_eH₅.NH₂ + H₂0. Some nitroso compounds (nitrosoantipyrin) have significance in pharmaceutical chemistry, in the chemistry of dyes.