Salvarsan

SALVARSAN, Salvarsan (Alt-Salvarsan Ehrlich-Hata 606), 4-4'-dihydroxy-3-3'-diamidoarsenobenzol hydrochloride ClHH₂N/\ /\NH₂HCl As=As Mol. wt. 475. Released in 1910 by the firm Meister, Lucius u. Brunning in Germany. In other countries S. is manufactured under the following names: in France - Arsenobenzol, Arsenobillon, Arsenobenzene, in England - Kharsivan, in Italy - Jacol, in Japan - Arsamino, Tanvarsan, Arsemin, in the USA - Arsphenamin; in 1915 it was introduced in Russia under the name Arsol (production discontinued); synthesized by Ostromyslensky. S. is included in the Russian Pharmacopoeia. Physical-chemical properties. S. is a pale yellow powder; colloidal. It has no melting point. It dissolves easily in methyl alcohol, ethylene glycol, glycerin and water, less easily in ethyl alcohol, insoluble in ether, acetone and benzene. Aqueous solutions have an acid reaction to litmus and a weakly violet reaction to congo. When 2 moles of caustic alkali are added to an aqueous solution of S., the base S. precipitates, which with further addition of alkali again goes into solution, forming phenolate. In a soda solution S. dissolves weakly and is completely insoluble in bicarbonate. For this reason, phenolate solutions turn cloudy on standing in air, absorbing carbon dioxide. S. is precipitated from strong aqueous solutions by adding strong hydrochloric acid. S., unlike neoarsphenamine, does not decolorize indigo carmine. Paramethylamidoazobenzole in dilute HCl gives an orange solution with S., from which an orange precipitate then falls out. When benzaldehyde and corrosive sublimate are added to the solution, the reaction becomes much more intense and can be used to detect S. in body tissues. Hydrogen sulfide in hydrochloric acid medium does not give a precipitate. Bettendorf's reagent gives a yellow amorphous precipitate. With ferric chloride, red coloration of solutions is obtained. Silver nitrate gives a dark red coloration of the solution, and when nitric acid is added, a brown precipitate falls out. The amino group in acidic medium is diazotized by sodium nitrite, and when an alkaline solution of resorcinol is added, an intense red coloration is obtained. This reaction is used to determine S. in urine. S. solutions, even without access to air, easily decompose on storage, and alkaline solutions are less stable than acidic ones. Moist S. decomposes when heated to 65°, dry S. is stable up to 175°. Dry S. is easily oxidized by atmospheric oxygen, turning into a 20 times more poisonous aminoxyphenylarsenoxide. S., prepared by reduction with hydrosulfite (blankite) from nitrooxyphenylarsenic acid, always contains a certain amount of S. with sulfin- and sulfogroups connected to the benzene nucleus. These sulfocompounds are approximately 2 times more toxic than salvarsan itself and have only half the therapeutic effect. The sulfur content is determined by the Carius method and ranges from 1% to 3%. Methods of obtaining S. The starting product for obtaining S. is nitro-3-oxy-4-phenylarsinic acid. 1) Reduction in one phase with hydrosulfite proceeds according to the following scheme: he Ano₂ 2

NaHSO₈. As=As Into an enameled vessel with a capacity of 30 liters with a stirrer, 13 liters of water, 513 g of magnesium chloride, 2,950 g of hydrosulfite are loaded, and a solution of 197 g of nitrooxyphenylarsinic acid in 4.5 liters of water and 135 cm³ of 10% solution of caustic soda is added. Heat on a water bath at 55-60° until complete precipitation of the S-base, which takes about 2 hours. The precipitate is filtered off and washed with water. The raw product is dissolved in 1,700 cm³ of methyl alcohol with the addition of methyl-alcoholic hydrochloric acid. The solution is filtered and S is precipitated by pouring the solution into a 10-fold volume of ether. The precipitate is filtered off, washed with ether, and dried in a vacuum over sulfuric acid. All operations are carried out in an atmosphere of carbon dioxide or nitrogen. 2) A purer product can be obtained by carrying out the reduction gradually: a) from nitrooxyphenylarsinic acid, 3-amino-4-oxyphenylarsinic acid is obtained; b) 3-amino-4-oxyphenylarsinic acid is reduced with sulfur dioxide in the presence of potassium iodide and sulfuric acid to aminooxyphenylarsenoxide; c) the obtained oxide is converted to S by hydrosulfite or sodium amalgam. 3) Excluding the obtaining of the oxide as an intermediate product, aminooxyphenylarsinic acid can be reduced to S by hydrosulfite or better electrolytically in a sulfuric acid medium on lead electrodes in the presence of iodine. When the solutions reduced by current are cooled, the sulfate of diamidodioxyarsenobenzene precipitates. The sulfate is dissolved in weak hydrochloric acid and its hydrochloride, i.e., S., is precipitated by strong hydrochloric acid, which is filtered off, washed with 20% hydrochloric acid, alcohol, ether, and dried in a vacuum desiccator. Analysis of S. 1) Determination of the impurity of aminooxyphenylarsenoxide: 1 g of S is dissolved in a volumetric flask to 100 cm³ in 10 cm³ of methyl alcohol, 25 cm³ of water are added. The S base is precipitated by gradual addition of 1.5 g of pure chalk. Water is added to make 100 cm³ and filtered through a dry filter into a dry flask. 50 cm³ of the filtrate are taken, 75 cm³ of water and 5 cm³ of hydrochloric acid are added to it. Titrated with ⁿ/₂₀ solution of iodine in the presence of starch. Good preparations require no more than 0.5-0.8 cm³ of iodine solution, which corresponds to the content of oxide in 0.5-0.8%. 2) S is titrated with iodine in a hydrochloric acid medium, oxidizing to aminooxyphenylarsinic acid: OHNH_aC_eH_eAs=AsC_eH₈OHNH_a+8J+ + 6H_aO=20HNH_aC_eH_aAsO_sH_a+8HJ. This reaction is the basis of the Gebel volumetric method for determining S. The reaction is reversible to a certain extent and therefore a corresponding correction is introduced. Experiments showed that for 1 mole of S, not 8, but only 7.509 atoms of iodine are consumed, \ so that 1 cm³ of ⁿ/₁₀ iodine corresponds to 0.006323 g of S. In addition, the content of arsenic and nitrogen is determined (methods-see below-neosalvarsan). Arsenic is usually contained several tenths less than the theoretical value, i.e., 31.6%, nitrogen-5.8%. S is weighed into ampoules of 0.1-S-,2- 0.3-0.4 g. The ampoules are evacuated and sealed. The drug is stored in the dark and in a cool place. Testing S on animals according to Kolle-Zueler: 6 mice are injected with 0.5 cm³ of a 1:150 solution of S, brought to solution by the addition of alkali. The solution is injected slowly to eliminate the possibility of shock. If 75% survive, the drug is considered "hyperideal"; if 60% survive, the drug is considered "ideal"; if less than 60% survive, the drug is rejected. The drug is used in the treatment of syphilis, relapsing fever and other diseases caused by spirochetes, as well as malaria. According to Kolle-Zueler, the German drug acts as follows: in rabbits with syphilis, doses per 1 kg of weight: MLD-1.25; MTD- dosis; MTD-max. tox. dosis; MCD-max. curat. dosis); in relapsing fever in mice, doses per 20 g of weight: MLD- Vmo> MTD - V^; MCD - Veoo, mtd ⁼ O! * Before being put on sale after testing on mice, the drug undergoes clinical examination. At present, Alt-Salvarsan ("606") is almost not used in medical practice, since the preparation of the solution requires the addition of alkali and due to its high toxicity, only weak, therapeutically less active solutions can be used; Alt-Salvarsan has therefore been displaced by easily soluble drugs of the Neosalvarsan type. Neosalvarsan, 914, Neosalvarsan (neoarsenol, neoyakol and other names of S in different countries with the addition of the prefixes "neo" or "new"); the drug was accepted by F VI. To replace Alt-Salvarsan, "salvarsan-sodium" was first introduced, which eliminates the alkalization when preparing solutions, but it did not find wide application. The most widely used is the neosalvarsan, introduced in 1912 by the firm Meister, Lucius and Bruening, which is a compound of S with rongalite (formaldehyde-sulfoxylate). According to German data, the drug has the following formula: он он HjNJ^ j^NH-CHaOSONa, As=AS mol. weight 466, but exact analyses show that there is an impurity of a disubstituted product: он -он NaOSOHoCHN^J f^NH-CHjOSONa. As=As Disubstituted S is less toxic than monosubstituted, but has a smaller therapeutic effect. The commercial drug is not an individual substance, which is shown by the arsenic content in the drug in the amount of 18-20%, whereas according to theory, monosubstituted S should contain 32.2%. It follows that the active substance in commercial neosalvarsan is 52-60%. 40-48% of impurities consist not only of the disubstituted product, but also of rongalite, sulfate, sulfite, sodium chloride, etc.- Neosalvarsan is a yellow or orange-yellow powder, easily soluble in water. The purer the drug, the more easily it dissolves. Easily soluble in glycerin, insoluble in methyl, ethyl alcohol, ether, and benzene. The reaction with unsubstituted amino group is the same as with S. An aqueous solution of neosalvarsan decolorizes indigo carmine-a difference from salvarsan. With ferric chloride, solutions of neosalvarsan and S first turn green; with further addition of ferric chloride, the S solution turns red, and the neosalvarsan solution turns violet. When heated with bisulfite, the S solution gives a yellow precipitate, while neosalvarsan does not give a precipitate. The drug is obtained by the method of P. F. Ryumin: the filtered and washed base after reduction of nitrooxyphenylarsinic acid with hydrosulfite is dissolved in methyl alcohol with the addition of HCl and filtered. To the obtained solution, the calculated amount of rongalite in aqueous solution is added and heated at 30°. The neosalvarsan acid precipitates as a sticky precipitate. The alcohol is decanted. Fresh alcohol is added and the precipitate is rubbed into a powder. To convert the acid of neosalvarsan into a salt, alkali is added to its suspension in alcohol. The neosalvarsan that precipitated is filtered off, the alcohol is decanted, it is dissolved in water, table salt is added, filtered, and poured into 96° alcohol. The resulting neosalvarsan is filtered off, washed with alcohol, ether, and dried in a vacuum first at ordinary temperature, then at elevated temperature. All reactions are carried out in an atmosphere of carbon dioxide or in a vacuum. The drug is stored in evacuated, sealed ampoules (not stable in air!), in the dark and in a cool place. Analysis of neosalvarsan (chemical control). 1) Arsenic content. Into a dry Erlenmeyer flask with a ground glass stopper, 0.2 g of neosalvarsan and 1 g of powdered potassium permanganate are introduced. 5 cm³ of 10% sulfuric acid are added and shaken for several minutes. 5-10 cm³ of concentrated sulfuric acid are added dropwise over 5-10 minutes. Hydrogen peroxide is added until the solution is decolorized, then 25 cm³ of water and boiled for 10 minutes. The mixture is diluted with 50 cm³ of water and the remaining hydrogen peroxide is destroyed by adding n/₁₀ solution of potassium permanganate until a faint pink color appears. By adding n/₂₀ oxalic acid, the solution is decolorized and boiled for 15 minutes. After cooling, 2.5 g of chemically pure potassium iodide are added, the flask is closed with a stopper and left for 1 hour in the dark. The solution is diluted with 150 cm³ of water and the liberated iodine is titrated with n₁₀ thiosulfate. 1 cm³ of n/₁₀ thiosulfate corresponds to 0.00375 g of arsenic.-2) Determination of nitrogen. 0.5 g of neosalvarsan is heated with 20 cm³ of concentrated sulfuric acid and a small amount of copper sulfate until the liquid is decolorized. After cooling, the flask is connected to a condenser, 80-100 cm³ of 33% caustic soda are added from a dropping funnel inserted into the stopper, and ammonia is distilled into a flask with 20-30 cm³ of n/₁₀ sulfuric acid, cooled with ice. The excess acid is titrated with n/₁₀ alkali. 3) Impurity of sodium chloride is determined as follows: 0.5 g of neosalvarsan is dissolved in 15 cm³ of water, 5 cm³ of 10% nitric acid are added. The flask is placed on ice for 10 min. The yellow precipitate of neosalvarsan acid is filtered off and washed with water.

To the filtrate add 10 cm³ of 10% sulfuric acid, heat to 70-80°, oxidize with ^p/₁₀ potassium permanganate until the color is constant, destroy the color with a few drops of 3% hydrogen peroxide, and precipitate chlorine with 10 cm³ of 5% silver nitrate. Leave overnight in a dark place: In the morning, filter the silver chloride through a Gooch crucible, wash the precipitate with water. Dry first at 100°, and then at 130° for an hour and weigh. -4) Determination of iodine number. By this number is understood the number of cubic centimeters of ^p/₁₀ iodine required to oxidize 0.1 g of neoarsphenamine. This number gives a comparative evaluation of the content of reducing impurities in neoarsphenamine (rongalite, sulfite). 0.1 g of neoarsphenamine is dissolved in 100 cm³ of water, 20 cm³ of ^p/₁₀ iodine is added, and the unused iodine is back-titrated with sodium thiosulfate until decolorization. 5) Determination of sulfur in neoarsphenamine is of very great importance, as it allows one to judge not only about the impurities and their composition, but also about what part of the product is in the mono- and what in the disubstituted form. Sulfur in neoarsphenamine occurs in the form: 1) bound to the amino groups of arsenic as its formaldehyde-sulfoxylate compound; 2) bound to the benzene nucleus of arsenic in the form of sulfinic and sulfonic groups, if the neoarsphenamine was prepared from arsenic obtained with hydrosulfite; 3) in the form of organic compounds not bound to arsenic (excess rongalite), and in the form of inorganic compounds (sulfate, sulfite).- Determination of total sulfur (A): the substance is heated in a sealed tube with nitric acid according to Carius. The resulting sulfuric acid is precipitated as barium sulfate and weighed. Only with such strong oxidation is sulfur bound to the benzene nucleus cleaved off.- Determination of sulfur bound to amino groups, together with sulfur in impurities (B): 0.2 g of neoarsphenamine is dissolved in water. The solution is boiled for 8 hours, maintaining a dark yellow color at all times by gradual addition of ^p/₁₀ iodine; evaporating water is replaced with fresh. The liquid is filtered and the filter is washed with water. To the filtrate add 3 cm³ of 10% hydrochloric acid, heat to boiling, and precipitate the resulting sulfuric acid with barium chloride as barium sulfate, which is filtered, dried, and weighed.- Determination of sulfur contained in impurities (C): 0.5 g of neoarsphenamine is dissolved in a small amount of water. To the solution add 5 cm³ of 10% hydrochloric acid and place on ice. The precipitated neoarsphenamine oxide is filtered and washed with water. The filtrate is oxidized with iodine as before, and sulfuric acid is isolated from it as barium sulfate. Barium sulfate is suctioned off on a Gooch crucible, dried, ignited to constant weight, and weighed. Calculation of results: A-B=amount of sulfur bound to the benzene nucleus. B-C=amount of sulfur bound to amino groups. C=amount of sulfur in impurities (organic and inorganic). In addition to determining the chemical composition, the physical properties of the preparation are also established, and the concentration of hydrogen ions in its aqueous solutions is determined. The color of the preparation should be yellow. Solubility: 0.2 g of the preparation is added in small portions, waiting each time for dissolution, into 5 cm³ of distilled water poured into a 40 mm diameter beaker. The total duration of the dissolution process should not exceed 5 min. The solution should not become cloudy upon addition of a few drops of a solution of sodium bicarbonate (arsenic impurity).- Determination of pH in a solution of neoarsphenamine: 0.6 g of neoarsphenamine is dissolved in 15 cm³ of distilled, well-boiled and cooled water without access to air. Buffer mixtures are prepared from solutions of 0.2 molar disodium phosphate in 1 l and 0.1 molar citric acid in 1 liter according to Kolthoff. To all test tubes add 1 drop of a 0.04% solution of bromthymol blue as an indicator, and compare the colors in a comparator: the pH of neoarsphenamine ranges from 6 to 7.8; according to data from the State Venereal Institute, pH ranges from 6.1 to 7.82 (L. Smorodintseva); the best, less toxic preparations have a pH of 7-7.5. Series of the preparation with acidic pH give a significant percentage of toxicity; high alkalinity can also cause toxicity; neutral pH (around 7.0) guarantees to a large extent both the non-toxicity of the series and their stability (data from the State Venereal Institute). Biological testing of neoarsphenamine. The necessity of biological testing of salvarsan preparations was firmly established by Ehrlich, when through numerous experiments on both animals and humans he became convinced that a certain chemical composition of the preparation does not guarantee a quite definite degree of toxicity and therapeutic effect. An explanation for this discrepancy between chemical composition and biological influence on a living organism was given by Bauer, who proved the colloidal nature of salvarsan preparations, and consequently the importance, in addition to chemical structure, of their physicochemical state (dispersity) for their physiological and toxic influence on the organism. The biological influence of salvarsan and its derivatives was studied by Ehrlich and his students on various animals (rabbits, rats, mice). There was no need for a specific instruction for general guidance on biological testing at that time, since the manufacture of salvarsan preparations was carried out according to patent by only one chemical plant (Hochst-Farbwerke), where the entire production process—up to biological testing—occurred under the direct supervision of Ehrlich himself. In other countries, similar biological control was carried out on the same animals, but according to standards not regulated by the state. In recent years, a number of countries have developed instructions of an official character (America, England, France, Italy, Poland). In the USSR for a number of years, testing of Soviet neoarsphenol was carried out according to an instruction developed by the State Commission for Testing Salvarsan Preparations and approved by the Academic Council of the People's Commissariat of Health. In 1933, in connection with the accumulation of a large amount of both Soviet and foreign material on biological testing, a special commission reviewed this question and came to the following conclusion: existing literary data on the methods of biological testing of salvarsan are very contradictory—while German researchers (the Kolle school) prefer the white mouse as the object, French authors (Léonard and Nicolle) consider the white mouse completely unsuitable for these experiments and recommend rabbits; American researchers (Kolmer, Kemberry) conduct experiments in parallel on mice and rats. The experiments of Soviet researchers also differ greatly: I. Krichevsky and Petrov saw satisfactory results in experiments on mice; Betz, Saveliev, and Yu. Finkel'shtein worked on rabbits. Stepan, although working on mice, however emphasized their increased sensitivity to salvarsan. - In general, in experiments on any animal, researchers do not consider it possible to predict with absolute certainty the course of salvarsan reactions in humans based on the reaction in animals. As for the so-called nitrite crises observed in humans, such, according to Yadasson, are not observed at all in animals. The above-mentioned literary discrepancies force the State Commission for Testing Salvarsan Preparations for the present moment to take as the basis for biological testing of Soviet neoarsenol the German method on mice and rats as the most standard (in the form of the German instruction) and approved by the Sanitary-Hygiene Section of the League of Nations and to a certain extent of an international character. Biological testing of neoarsphenamine is divided into determining toxicity and determining therapeutic effect in experiments on animals. Determination of toxicity. A series is tested by three different researchers. Two ampoules of 0.3 g each are taken, each of which serves for an experiment on 5 mice with an average weight of 15 g. In addition, by one researcher from one ampoule, the toxicity is determined on 5 rats with an average weight of 150 g. Thus, the preparation is administered to 30 mice and 5 rats. The test is carried out by intravenous administration to mice and rats of the limiting doses indicated below, from which some animals may die (borderline tolerable dose). The doses are established for mice at 20 g, and for rats at 1 kg of body weight (well-fed, but fasted for 4 hours animals). The duration of observation for mice is 3, and for rats-6 days. 0.3 g of the series is placed in a Jena glass flask with a capacity of 10 cm³, filled with 6 cm³ of doubly distilled water, so that the powder is on the surface of the water. In case of precipitate formation, the latter is dissolved by gentle shaking of the flask or with the help of a pipette. From this 5% stock solution, the necessary dilutions are prepared using 0.6% physiological solution. In the first series of experiments, 5 mice receive intravenously 1 cm³ each of a 1:135 dilution, in the second-1 cm³ each of a 1:120 dilution per 20 g of body weight. The solution is administered heated to 30°. In addition, 5 rats (average weight 150 g) are injected into the tail vein with 4.5 cm³ of a 5% solution per 1000 g of body weight (0.225 g of neoarsphenamine per 1 kg).

The injection of the solution should be done slowly to prevent shock - approximately in half a minute. The assessment of the perfection of the released series in terms of toxicity is carried out by comparing individual series of experiments based on the generalized result of all tests. The released series is considered suitable if 60% of mice that received a dilution of 1:135 survive, and 50% of mice that received a concentration of 1:120 survive, and 60% of rats. Determination of therapeutic effect. The therapeutic effect is tested by experiments on infected mice, by comparison with standard neosalvarsan. 24 mice are infected with freshly obtained serum from the blood of a mouse infected with trypanosomes. The serum is diluted with 0.85% physiol. solution in such a way that in each field of view at a magnification of about 400 there should be 8-10 trypanosomes. 0.5 cm³ of this serum is injected subcutaneously into each mouse. The next day, about 4-9 trypanosomes should be found in 40 fields of view in these mice. With such an intensity of infection, the animals are used for testing the therapeutic effect. 9 mice are injected intravenously with standard neosalvarsan, the same number of mice are injected with the test series, and in both series of experiments every 3 mice receive the same doses. The remaining 6 mice are left untreated as a control over the course of the infection. The table below shows the average doses used in testing the therapeutic effect: vi, taken on a cover slip from the tail, in the same way at a magnification of about 400 with a record of the count results. The blood research data is recorded as follows: Standard neosalvarsan Test neosalvarsan 3 mice - 1: 12,000 3 mice - 1 : 8,000 3 mice - 1 : 5,000 1 : 12,000 1 cm³ per 20 g} 1 : 8,000 1 cm* per 20 g 1 : 5,000 1 cm» per 20 a In all animals, blood examination is performed daily during the 10-day observation period, with at least 40 fields of view of the blood smear being examined. ⁺ \ +++ 1- 3 parasites in 40 fields of view 1- 9", "", "" each field of view ......9 and more parasites in each field view In the table below is given the average assessment of the course of infection caused by the trypanosome strain used in treatment with standard neosalvarsan. Standard salvarsan (mice infected the day before and show +). Day 1 : 12,000 1 : 8,000 1 : 5,000 + + + + + 1 - +-m- ++ - + - + j - - +++ - ++ - 1 - - +++ j ~ 7 8 | + + ++ ++!-{- Myosalvarsan (Myosalvarsan-France), sulfosalvarsan (Sulfosalvarsan-Germany), sulfarsphenamin (Sulfarsphenamin - USA). Disodium salt of 3,3'-diamino-4,4' dihydroxyarsenobenzol dimethane-disulfonic acid: он он NaOaSOHaCHNr⁴] (^NHCHaOSOaNa. As^=As These preparations have not been included in the Russian Pharmacopoeia. Myosalvarsan is manufactured in France by R. Pluchon, Paris and was introduced into use in 1919. It is a light-yellow powder (French pure yellow, German has an orange tint), extremely soluble in water. Aqueous solutions are much more stable than neosalvarsan solutions. Insoluble in alcohol, ether, and acetone. When heated, the preparation, without melting, decomposes with the release of sulfurous acid. Indigo carmine is decolorized only if the myosalvarsan solution is treated with zinc dust and acetic acid and indigo carmine is added to the filtrate (difference from neosalvarsan). The free myoacid can be precipitated from aqueous solutions with acetic acid. When it is analyzed (see above neosalvarsan and salvarsan), the ratios of sulfur, nitrogen, and arsenic atoms are obtained as 1:1:1, which indicates a displaced product. Theoretically, the arsenic content in the preparation should be 25.06%, but the commercial product contains only 18.5-19.5%, which indicates foreign impurities (as in neosalvarsan). To prepare myosalvarsan, one starts from base C, which is weighed in 3 parts water, 0.3 parts of 40% formaldehyde and 1 part of 40% sodium bisulfite are added. Heated until completely dissolved. The myoacid is precipitated with hydrochloric acid, which is suctioned off, washed with water, dissolved in water, neutralized with soda, and precipitated with alcohol or acetone. The suctioned and washed with absolute alcohol product is dried in a vacuum. One can also start from C. (hydrochloride salt), dissolving it in 10% alcohol and treating with formaldehyde and bisulfite. The precipitate that initially forms dissolves again. When poured into strong alcohol, myosalvarsan precipitates. Analysis is carried out as with neosalvarsan. The preparation is used in the same cases as neosalvarsan, but unlike the latter, it can be administered intramuscularly. The trypanocidal properties of myosalvarsan are somewhat weaker than those of neosalvarsan. According to Raiziss, for 1 kg of rats with intravenous administration: MLD-320-480 mg, MCD-15.9-31.5 mg.

Silbersalvarsan. The preparation is not included in the Russian Pharmacopoeia. ONa ONa As= Г>н₂ ЧУ/Ag =As( ^xOH This formula (Binz) is controversial, as Ehrlich and Carrer and Binz and Bauer give others. Silbersalvarsan was first obtained by Ehrlich and Carrer. It was biologically and clinically studied by Kolle and introduced into medical practice by him in 1918. The preparation is a dark brown powder, easily soluble in water, with an alkaline reaction. Insoluble in diluted mineral acids and bicarbonate. Silver ions are not detected by ordinary reagents. In ampules without air access, it is preserved well, on air it oxidizes easily and then gives turbid solutions in water. Method of preparation: to a solution of 1 mole of C. in methyl alcohol, a methyl alcohol solution of 6 moles of caustic soda is added. To the resulting solution, 1 mole of lunar caustic in methyl alcohol is added. From the solution, silbersalvarsan is precipitated by absolute ether. The precipitate is suctioned off, washed with ether, and dried in a vacuum. Analysis: arsenic is determined as with C., it contains about 22%. Silver is determined as follows: 0.3 g of the preparation is mixed with 2 g of permanganate, 10 cm³ of 10% and then 10 cm³ of concentrated sulfuric acid are added. It is allowed to cool, 50 cm³ of water are added and it is titrated by the Volhard method with ammonium thiocyanate. 1 cm³ *V₁₀₀ of ammonium thiocyanate corresponds to 0.00108 g of silver. Usually contains 13-14% silver. The preparation has the best index of all known arsenic preparations. For rabbits per 1 kg of weight toxic dose-0.125, tolerable dose-0.1, therapeutic dose-0.004, index 1:25. For mice per 20 g of weight toxic dose-¹/₂₂₅, tolerable dose-^1/зoo₅ therapeutic dose-¹/₁₀₀₀, index 1:3.5. Despite the good index, it is tolerated worse than neosalvarsan, because with it side effects are more often observed.

Neosilbersalvarsan. The preparation is included in the Russian Pharmacopoeia. Its structure is not established. It is a brown powder, easily soluble in water, with a neutral reaction, solutions slightly fluoresce. It is stable in air unlike C. and neosalvarsan. It is not precipitated from aqueous solutions by carbon dioxide (difference from silbersalvarsan). Method of preparation, developed by Aniltrest: 100 g of neosalvarsan are dissolved in 3 l of water, a solution of 240 g of lunar caustic in 480 om³ of water is added. The solution is poured into a mixture of alcohol with ether 1:1. The precipitate that forms is suctioned off, washed with ether and dried in a vacuum. Yield 960 g. The preparation contains 20% arsenic and 8% silver. It is used in the same cases as neosalvarsan. For rabbits per 1 kg of weight MLD-0.15; MTD- ОДЗ; MCD-0.01; index-1:13. For mice per 20 g of weight MLD -VIso," MTD - VIw; MCD-*/₅₀₀; index-1:3. Osarsol (Osarsol-USSR), stovarsol (Stovarsol-France), spirosid (Spirozid - Germany), Fourneau 190. The preparation is not included in the FUP. 4-hydroxy-3-acetamidophenylarsonic acid, он NH-COCHa, AsO₃H₂ mol. weight. 275. Arsenic content-27.27%. Colorless needles. Without melting, it decomposes at 208-210°. Very slightly soluble (about 1%) in water, alcohol, and 80% acetic acid. Soluble in soda and alkalis. When heated with alkalis and acids, it loses the acetyl group. First put on sale in 1922 in France by Poulenc freres. The starting product for osarsol is 4-nitro-3-hydroxyphenylarsonic acid, which is reduced to the corresponding amino acid. The amino acid is acetylated он"

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It is 3-amino-4-hydroxyphenylarsonic acid (Fournier 189) and is an important intermediate product for obtaining not only arsphenamine, but also Salvarsan. It consists of pale pink crystals, sparingly soluble in water and alcohol. Its salts, both with mineral acids (compounds with the amino group) and with alkalis (with the arsenic acid group), are readily soluble in water. Alkaline solutions turn brown in the air due to oxidation, while acidic solutions are stable. The methods for obtaining the amido-hydroxyphenylarsinic acid are based on the reduction of nitro-hydroxyphenylarsinic acid 1) with iron in a hydrochloric acid medium or 2) electrolytically in sulfuric acid. In both cases, the obtained amino acid is isolated as the chlorohydrate, which is sparingly soluble in a saturated salt solution. Other methods of obtaining it are little suitable for factory installations. 1) 263 g (1 mole) of nitro-hydroxyphenylarsinic acid are added with good stirring to 1,750 cm³ of 5% hydrochloric acid, maintaining the temperature at 40-60°, and gradually introducing 170 g of iron filings. The resulting solution is filtered and the chlorohydrate is salted out with 250 g of salt. After cooling, the chlorohydrate is suctioned off. 2) 263 g of 'nitrooxy' are weighed in 2 liters of 4% sulfuric acid. It is loaded into an electrolyzer with a diaphragm and copper cathode. 40 g of ferrous sulfate is added and current is passed (about 170 ampere-hours until vigorous hydrogen evolution). The solution is filtered and 500 g of salt is added. After cooling, the precipitated chlorohydrate of amido-hydroxyphenylarsinic acid is filtered off. The crude chlorohydrate is purified by crystallization from 4% hydrochloric acid. Preparation of arsphenamine. The chlorohydrate of amido-hydroxyphenylarsinic acid, obtained from 1 mole of nitro-hydroxyphenylarsinic acid, is dissolved in 1 liter of water with gentle heating. Hydrosulfite (5 g) and charcoal are added, and it is filtered. A concentrated solution of sodium acetate is added first until cloudiness appears, then simultaneously with good stirring and as quickly as possible, 200 cm³ of acetic anhydride and 140 cm³ of a 33% solution of sodium acetate are added. The solution is acidified with hydrochloric acid to a Congo blue reaction, and after some time the precipitated arsphenamine is suctioned off. For purification, arsphenamine is dissolved in soda, filtered, and salt is added. The sodium salt of arsphenamine precipitates; it is suctioned off, washed with a concentrated salt solution, again dissolved in water, and precipitated by acidifying with hydrochloric acid to obtain pure arsphenamine. The product is suctioned off, washed with water, alcohol, and ether, and dried in the air. Arsphenamine is tested for arsenic content (as salvarsan). The commercial product contains 27.2-27.4% arsenic (theory requires 27.27%). Solutions of the preparation in dilute soda should be almost colorless, which indicates that the product does not contain free, non-acetylated amido-hydroxyphenylarsinic acid, which is easily oxidized and gives toxic compounds.

G. Kirchhoff. Clinical application of salvarsan. Ehrlich, who introduced salvarsan (Alt-Salvarsan) into the therapy of syphilis, sought with this means to achieve therapia magna sterilisans, i.e., the cure of the disease with a single administration of the drug (Weise). However, Ehrlich himself had to recognize, and all subsequent history of salvarsan preparations has confirmed, the impossibility of curing syphilis with a single injection of S. Most of the S. preparations listed above are currently administered almost exclusively intravenously. For intramuscular injections, the following compounds have been proposed: 1) myo-salvarsan; 2) Sulfarsenol and Sulfotreparsenan; these preparations are particularly successfully used in pediatric practice, and according to French authors, the latter preparation is distinguished by extremely easy local and general tolerance and convenience of application; 3) Acetylarsan, which despite high therapeutic activity still yields to preparations of the neosalvarsan type; 4) very recently in Germany, I.G. Farbenindustrie has released a new preparation '4686' (Solusalvarsan); it is released for use in a 10% solution and is currently being clinically tested in Germany. In addition to the preparations mentioned above, complex organic compounds of pentavalent arsenic, proposed by Levaditi and Navarro-Martin in 1922 in a preparation released under the name Stovarsol (No. 190), have become widely used. These preparations were soon manufactured in Germany under the name Spiro-cid, in the USSR under the names stovarsolan, stovarsol, and then arsarsol. The main advantage of preparations of the arsarsol type lies in their oral administration, which significantly simplifies the technique of syphilis treatment. However, having been tested on a vast amount of material in France, Germany, and the USSR, these preparations in terms of therapeutic effect proved to be somewhat inferior to neosalvarsan. They find particularly wide application in pediatric practice (M. Lesser, Mettenheim, Smelov). Sezary and Barbe (Sezary, Barbé) proposed in the treatment of general paralysis to inject the sodium salt of stovarsol intravenously. Indications for the use of salvarsan preparations are, first of all, all periods of syphilis, especially its contagious manifestations, malaria, relapsing fever. Stovarsol in addition to syphilis is also used in some helminthiases (Trichocephalus dispar), amebic dysentery, lambliosis. In the treatment of syphilis, all the preparations mentioned above are usually used in combination with bismuth, mercury, and iodine, as well as various forms of non-specific therapy (malaria, spa treatment of syphilis). Absolute contraindications for the use of all salvarsan preparations are: severe kidney and liver diseases, febrile conditions of non-syphilitic origin, acute widespread dermatitis, acute gastrointestinal diseases, hemorrhagic diathesis, gastric and duodenal ulcer, sharply expressed degenerative changes of the central nervous system. Special caution and individualization are required both in terms of dosages and intervals between infusions in the following cases: during pregnancy, heart and vascular diseases, age above 50 years in men and 45 years in women, chronic intoxications, severe exhaustion, severe anemias, epilepsy, in the first 3 days of the menstrual period, in chronic gastrointestinal tract diseases, kidney diseases not accompanied by reduced diuresis and edema, the presence of purulent and putrefactive foci in the body, diseases of the auditory and optic nerves, Addison's disease, Basedow's disease, diabetes, myxedema and status thymico-lymphaticus, widespread dermatoses, the presence in the anamnesis of a large number of acute infectious diseases, as well as liver and kidney diseases, diseases of the central nervous system not accompanied by severe degenerative changes, lesions of the larynx with difficult breathing, poor tolerance in the past of arsenic preparations. In preparing solutions of neosalvarsan, freshly distilled water must be used, boiled before infusion, the temperature of which should be about 20°. The solution is prepared for each patient immediately before infusion; the latter is recommended to be done 2 hours after a light breakfast so that the subsequent intake of food should not be earlier than 2-3 hours after infusion. The ampoule must be carefully inspected; if there are cracks in the glass, as well as the slightest changes in the physical properties of the preparation (in terms of color, consistency, fluidity of the powder), the latter must in no way be allowed for use. Solutions of neosalvarsan should be prepared at the rate of 1.0-2.0 water per 0.1-0.2 cm³ of preparation and be completely transparent; infusions should be done only by doctors well versed in the technique of intravenous infusions, since the entry of even small amounts of the neo solution into the paravenous cellular tissue leads to very painful and very persistent infiltrates, often hindering further treatment, especially in subjects with poorly developed veins. Infusions should be performed slowly (1-2 minutes). During treatment, especially on the eve and on the days of neo infusions, patients should avoid physical exertion, the use of alcoholic beverages. S. (Alt-Salvarsan) is used in single doses of 0.1-0.2-0.3-0.4, and per course-2.5-3.0-4.5; Myosalvarsan-0.15-0.3-0.45-0.6, per course-4.0-5.0-6.0; neosalvarsan-type preparations (Russian Novarsenol) are recommended to be used in the following doses: for the first infusion 0.15 for women, 0.15-0.3 for men; in subsequent infusions the dosage is increased by 0.15 for each infusion, with the highest single dose for women being 0.45, and for men-0.6. The course dose for adults should not exceed 4.0-6.0 of the preparation depending on the general condition of the body and the period of syphilis. For infants, the single dose for the first infusion should not exceed 0.01 per 1 kg of weight; for subsequent ones it can be increased to 0.02-0.03 of the preparation per 1 kg of weight; for children from 1 year to 5 years the single dose should not be higher than 0.01-0.015 of the preparation per 1 kg of the child's weight, however in general not higher than 0.15-0.2 of novarsenol. For children from 5 years and older, 0.01 cm³ of the preparation per 1 kg of weight is used, however with such a calculation that the single dose is not higher than 0.15-0.25 for children from 5 to 10 years and 0.25-0.45 for children from 10 to 16 years. Intervals between infusions for adults after a dose of 0.15-two-three days, after 0.3-three-four days, after 0.45-five-six days, after 0.6-six-seven days; for children intervals should be at least 5 days. When using arsarsol, we have approximately the same absolute and relative contraindications (see above) as when using neosalvarsan. During treatment here careful attention is paid to the condition of the gastrointestinal tract. The preparation is used in the form of tablets or powder. Each tablet contains 0.25 of stovarsol. The daily dose is divided into 2 intakes: the first-in the morning on an empty stomach, the second-in the evening on an empty stomach (3 hours after taking food), washing down with a small amount of water. In adults, the preparation is used in doses starting from 0.25 to 1.0 per day, with the preparation given for 5 consecutive days, after which a 3-5-day break is made, and then again 5 days of taking the preparation and so on until the total course dose of 30.0-40.0 g. For children the following dosages are recommended, used in the State Venereal Institute in Moscow: Age Single dose Daily dose Course dose 1-6 mos. 0.06 0.06 × 2 = 0.12 4.0 6 mos.-1 yr. 0.03 0.06 × 4 = 0.24 6.0 1-2 yrs. 0.1 0.1 × 3 = 0.3, 0.1 × 4 = 0.4 8.0 2-5 yrs. 0.25 0.1 × 4 = 0.4, 0.25 × 2 = 0.5 10.0 5-8 yrs. 0.25 0.25 × 2 = 0.5 15.0 8-12 yrs. 0.25 0.25 × 2 = 0.5, 0.25 × 3 = 0.75 20.0 12-16 yrs. 0.25 0.25 × 3 = 0.75 25.0 Arsarsol in children is used according to the following scheme: 1st day-one single dose is given, 2nd day-2 single doses (morning and evening), 3rd day-3 single doses (2 in the morning and 1 in the evening), 4th day-4 single doses (2 in the morning and 2 in the evening). After this it is necessary to take a break in treatment for 5 days. Then for 5 days the full daily dose is given (½ in the morning and ½ in the evening), after which again a break of 5 days; thus treatment is carried out until the full course dose is obtained. According to a somewhat different scheme, arsarsol is used in the treatment of trichocephaliasis (see Whipworm). Arsarsol in the treatment of syphilis should be used in combination with Bi or Hg. Side effects of S. When using all salvarsan preparations, side effects may be observed. Their quantity and quality are extremely different among different authors. In Kaplun and Shenefeld, out of 63,324 infusions of various salvarsan preparations, side effects were noted in 376 cases, of which 165 were mild, 41 were nitrite crises, 84 were exanthemas, 81 were jaundices, 4 were serous apoplexies, 1 was a salvarsan shock; fatal outcome was in 3 cases (2 after the use of neosalvarsan and 1 after neosalvarsan).

According to American authors, out of 1,212 patients treated with various preparations of Salvarsan, 252 experienced various complications, with a fatal outcome in 12 cases; the Cologne Commission of 1918 recorded 12 deaths from 225,730 injections, however, when accounting for injections of Neoarsphenamine in doses not exceeding 0.6, according to this commission, 1 death occurs per 162,792 injections. The pathogenesis of side effects is extremely complex and varied. While in some cases the cause of complications is: 1) insufficiently sterile water, 2) poor quality of the drug ampule, 3) toxic series of Salvarsan, 4) too careless both single and total dosages, 5) short intervals between individual injections, 6) insufficient caution in using the drug in relative contraindications, in other cases, in the absence of these causes, various theories are put forward to explain side effects: Hoffmann (E. Hoffmann) considers functional liver damage as the cause of Salvarsan dermatitis; I. L. Krichevsky sees the cause of side effects in changes in the physicochemical properties of blood colloids and cells; according to Stuhmer, Salvarsan complications are phenomena of anaphylaxis; Tachau (P. Tachau) believes that in some cases with side effects after using Salvarsan, we are dealing with idiosyncrasy, as is observed when using mercury, iodoform, antipyrine, quinine, etc., as indicated by Jadassohn, and along with rare cases of congenital idiosyncrasy, acquired idiosyncrasy is more often observed, namely when side effects occur after repeated injections of Salvarsan, often even only during repeated treatment courses. This hypersensitivity in some cases turns out to be extremely persistent and forces one to abandon further use of the drug; in other cases, habituation to the drug occurs and it is well tolerated by patients. The clinical picture of side effects is varied. In the vast majority of cases, a complex toxic symptom complex develops, in which the phenomena from the skin, liver, or central nervous system, etc., come to the forefront. Completely isolated lesions of any organ are observed less frequently. Thus, skin or internal organ lesions often combine with each other, and at the same time can be accompanied by meningeal phenomena, a toxic rise in temperature. By the time of onset, side effects can be divided into 3 groups: 1) those occurring during or shortly after the injection; 2) developing from several days to 1-2 weeks after the last injection; 3) appearing after longer intervals. Early complications include: 1) the smell of ether or garlic, nausea and vomiting occurring during the injection, 2) skin itching and rapidly disappearing urticarial rashes, 3) temperature reactions, which must be distinguished from the Jarisch-Herxheimer reaction, 4) nitritoid crisis (Münch), which received this name because approximately the same phenomena are observed as with the use of amyl nitrite. The latter complication, described by most German authors under the name of angioneurotic symptom complex, consists either in redness or paleness of the skin of the face, neck, in the appearance of edema in these places, as well as on the lips, tongue; all these external signs of poisoning can be accompanied by a decline in cardiac activity, and sometimes also complications from the gastrointestinal tract in the form of nausea, vomiting, and diarrhea. Complications of the 2nd group include lesions of the skin (see Dermatitis), liver (see Jaundice, Acute yellow atrophy of the liver), kidneys (see Nephrosis, clinical forms), blood (see Leukopenia), joints and nervous system (see Neurorecurrence). Among the most severe side effects from the central nervous system is hemorrhagic encephalitis, purpura cerebri or serous apoplexy (Münch). Sicard, Césari, Sobolev, and others have described cases of Salvarsan peripheral neuritis. The clinical picture of the disease in this case comes down to various paresthesias, and sometimes to the disappearance of Achilles reflexes; such cases can simulate true tabes dorsalis, which is why French authors introduced the term 'arsenical pseudotabes' (pseudo-tabes arsenobenzenique) for these forms of peripheral neuritis. Among the rare side effects are lesions of the oral mucosa (stomatitis), first most thoroughly described by Simon (Cl. Simon). Differential diagnosis of side effects often presents great difficulties, especially in cases where the complication developed a more or less long time after the end of treatment. In such cases, one often has to think of so-called monorecurrences, i.e., isolated syphilitic lesions of one or another organ (more often when talking about neurorecurrences or monogepatorecurrences), not accompanied by external manifestations of syphilis, as well as positive serological reactions. Careful clinical observation, and sometimes cautiously undertaken iodine, bismuth, or mercury therapy, usually allows one to decide whether we are dealing with a toxic or syphilitic lesion of the organ. Side effects in their course can turn out to be extremely treacherous: a mild onset does not guarantee against a further severe course, and conversely, a severe onset often ends in rapid recovery. It is also necessary to note the ability of some side effects (dermatitis) to spontaneously recur. To prevent severe side effects, it is recommended to adhere to the following rules: 1) it is necessary to instruct patients that for any malaise occurring after an injection of Salvarsan, they should consult a doctor; 2) when side effects occur, all specific treatment must be stopped and subsequent injections should be done only after complete recovery, however not earlier than 7-8 days, and in a reduced dose; 3) all severe side effects require a long discontinuation of Salvarsan treatment (not less than 3-4 months after the disappearance of all signs of complication) and special caution in dosages in the future. Treatment of side effects usually comes down to symptomatic therapy. In addition, when a nitritoid crisis or hemorrhagic encephalitis occurs, subcutaneous injection of adrenaline (1 cm³ of 1% solution of Adrenalini hydrochlorici) is recommended; for all side effects, intravenous injections of 10-20% solution of Natr. hyposulfurosi, 10% solution of Calcii chlorati are recommended; Mülpfört recommends prescribing the so-called 'Mixture acid' according to the following prescription: Acid. hydrochlorici dil. 20.0, Sir. Rubi Idaei 60.0, Aq. destillat. ad 200.0. MDS 3 times a day by the teaspoon. In cases of poor tolerance to Salvarsan, for the prevention of side effects, it is recommended to dissolve the drug in a 10% solution of calcium chloride, 50% solution of glucose, inject subcutaneously shortly before the injection of Salvarsan 0.5-1.0 cm³ of a 1/1000 solution of adrenaline; Colle, Schlosberger and Leupold inject particularly sensitive subjects 24 hours before the injection of the normal dose of Salvarsan 0.05-0.1 of this drug. When using Neosalvarsan, the same relatively mild side effects are observed as with Salvarsan, however in the vast majority of cases, according to the unanimous opinion of most Russian and foreign authors, they occur significantly less frequently and their course is milder. When they occur, treatment with Neosalvarsan is discontinued until the complication completely disappears. Resumption of treatment is allowed no earlier than 5-7 days after the regression of side effects. In cases of severe side effects, as well as when they develop repeatedly, treatment with Neosalvarsan is recommended to be completely discontinued. The therapy for Neosalvarsan complications is the same as for Salvarsan side effects, according to Smelov. Discovery in legal cases. Salvarsan as such cannot be discovered in the parts of the corpse due to decomposition, and its discovery comes down to the discovery of arsenic (see). In urine, Salvarsan (and its derivatives) can be discovered in the first hours after administration to the body by converting it to an azo dye. The urine is acidified with hydrochloric acid, cooled to 0° and added dropwise 0.5% solution of sodium nitrate (until a drop of urine does not turn blue a paper moistened with a solution of potassium iodide and starch paste). The resulting liquid is poured as a layer onto a 1% solution of resorcinol, made alkaline with caustic soda: at the boundary of the two layers a red ring appears. Instead of the resorcinol solution, α-naphthylamine can be used.

VARSAN