{"id":29919,"date":"2025-11-11T11:40:09","date_gmt":"2025-11-11T04:40:09","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=29919"},"modified":"2025-11-11T11:40:09","modified_gmt":"2025-11-11T04:40:09","slug":"sodium-aurothiomalate","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/sodium-aurothiomalate\/","title":{"rendered":"Sodium Aurothiomalate"},"content":{"rendered":"

(Ph. Eur. monograph 1994)<\/p>\n

Action and use<\/strong><\/p>\n

Used in the treatment of rheumatoid arthritis.<\/p>\n

Preparation<\/strong><\/p>\n

Sodium Aurothiomalate Injection<\/p>\n

DEFINITION<\/h2>\n

Mixture of monosodium and disodium salts of (2RS)-2 (aurosulfanyl)butanedioic acid.<\/p>\n

Content<\/h3>\n

\u2014 gold (Au; Ar 197.0): 44.5 per cent to 46.0 per cent (dried substance);<\/p>\n

\u2014 sodium (Na; Ar 22.99): 10.8 per cent to 11.8 per cent (dried substance).<\/p>\n

CHARACTERS<\/h2>\n

Appearance<\/h3>\n

Fine, pale yellow, hygroscopic powder.<\/p>\n

Solubility<\/h3>\n

Very soluble in water, practically insoluble in ethanol (96 per cent) and in methylene chloride.<\/p>\n

IDENTIFICATION<\/h2>\n

A. Dissolve 20 mg in water R and dilute to 2 mL with the same solvent. Add 2 mL of strong hydrogen peroxide solution R and 1 mL of sodium hydroxide solution R. Carefully heat to boiling and boil for 30 s. A precipitate is produced that appears brownish-black by reflected light and bluish-green by transmitted light.<\/p>\n

B. To 20 mg add 2 mL of water R. The solution gives reaction (a) of sodium (2.3.1).<\/p>\n

C. Ignite 100 mg, dissolve the residue in hydrochloric acid R and dilute to 10 mL with the same acid. Allow to stand. 5 mL of the clear supernatant gives reaction (a) of sulfates (2.3.1).<\/p>\n

TESTS<\/h2>\n

Appearance of solution<\/h3>\n

Dissolve 1.0 g in water R and dilute to 10 mL with the same solvent. Filter, seal in an ampoule and heat at 100 \u00b0C for 1 h. Cool and dilute the contents of the ampoule to 100 mL with water R. The solution remains clear and is not more intensely coloured than a 0.100 g\/L solution of potassium ferricyanide R.<\/p>\n

pH (2.2.3)<\/h4>\n

6.0 to 7.0.<\/p>\n

Dissolve 1.0 g in carbon dioxide-free water R and dilute to 10 mL with the same solvent.<\/p>\n

Related substances<\/h3>\n

Liquid chromatography (2.2.29). Prepare the solutions immediately before use.<\/p>\n

Test solution: Dissolve 0.200 g of the substance to be examined in water R and dilute to 100.0 mL with the same solvent.<\/p>\n

Reference solution (a): Dissolve 10.0 mg of fumaric acid R and 100.0 mg of thiomalic acid R in water R and dilute to 100.0 mL with the same solvent. Dilute 1.0 mL of this solution to 25.0 mL with water R.<\/p>\n

Reference solution (b): Dissolve 12.0 mg of thiomalic acid R in water R and dilute to 100.0 mL with the same solvent.<\/p>\n

Reference solution (c): Dissolve 10.0 mg of maleic acid R in water R and dilute to 100.0 mL with the same solvent. Dilute 1.0 mL of this solution to 25.0 mL with water R.<\/p>\n

Column:<\/p>\n

\u2014 size: l = 0.25 m, \u00d8 = 4.6 mm;<\/p>\n

\u2014 stationary phase: base-deactivated end-capped octadecylsilyl silica gel for chromatography R (5 \u03bcm).<\/p>\n

Mobile phase: Mix 90 volumes of a 10.5 g\/L solution of phosphoric acid R, 100 volumes of methanol R2 and 810 volumes of water R.<\/p>\n

Flow rate: 1.0 mL\/min.<\/p>\n

Detection: Spectrophotometer at 205 nm.<\/p>\n

Injection: 10 \u03bcL.<\/p>\n

Run time: Twice the retention time of impurity C.<\/p>\n

Relative retention: With reference to impurity C (retention time = about 8 min): impurity A = about 0.4; impurity B = about 0.6. Aurothiomalate does not elute under the chromatographic conditions described.<\/p>\n

System suitability: Reference solution (a):<\/p>\n

\u2014 resolution: minimum 5.0 between the peaks due to impurities B and C.<\/p>\n

Limits:<\/p>\n

\u2014 impurity A: not more than the area of the principal peak in the chromatogram obtained with reference solution (c) (0.2 per cent);<\/p>\n

\u2014 impurity B: not more than the area of the corresponding peak in the chromatogram obtained with reference solution (a) (0.2 per cent);<\/p>\n

\u2014 impurity C: not more than the area of the principal peak in the chromatogram obtained with reference solution (b) (6.0 per cent).<\/p>\n

Maximum 8.0 per cent.<\/p>\n

Test solution: Dissolve 0.50 g of the substance to be examined in water R and dilute to 10 mL with the same solvent.<\/p>\n

Reference solution (a): Dilute 0.80 g of glycerol R to 100.0 mL with water R.<\/p>\n

Reference solution (b): To 2.5 mL of reference solution (a) add 7.5 mL of water R.<\/p>\n

Reference solution (c): To 5.0 mL of reference solution (a) add 5.0 mL of water R.<\/p>\n

Reference solution (d): To 7.5 mL of reference solution (a) add 2.5 mL of water R.<\/p>\n

Blank solution: 10 mL of water R.<\/p>\n

To the test solution, reference solutions (b), (c) and (d) and the blank solution, add 2.5 mL of a freshly prepared 235 g\/L solution of sodium hydroxide R and mix. Add dropwise in 0.2 mL increments a 38.0 g\/L solution of cupric chloride R, shaking vigorously after each addition, until the solutions become slightly turbid. Then add 0.2 mL of the 38.0 g\/L solution,of cupric chloride R. Stopper and shake vigorously for 1 min. Dilute to 25.0 mL with water R and mix. Centrifuge for 2 min. Measure the absorbance (2.2.25) of the supernatant of a 1 cm layer at 635 nm. Use the solution prepared from the blank solution as the compensation liquid. Draw a calibration curve and calculate the content of glycerol in the sample.<\/p>\n

Loss on drying (2.2.32)<\/h4>\n

Maximum 2.0 per cent, determined on 1.000 g by drying in a desiccator at a pressure not exceeding 0.7 kPa for 24 h.<\/p>\n

ASSAY<\/h2>\n

Gold<\/h3>\n

Heat 0.2 g with 10 mL of sulfuric acid R and continue to boil gently until a clear, pale yellow liquid is produced. Cool, add about 1 mL of nitric acid R dropwise and boil for 1 h. Cool, dilute to 70 mL with water R, boil for 5 min and filter. Wash the residue of gold with water R at 60 \u00b0C. Dry and ignite at a temperature of at least 600 \u00b0C for 3 h. Weigh the residue and calculate the percentage content of Au.<\/p>\n

Sodium<\/h3>\n

Evaporate to dryness the filtrate and washings obtained in the assay for gold, moisten with sulfuric acid R and ignite at 600 \u00b1 50 \u00b0C for 3 h.<\/p>\n

1.000 g of residue is equivalent to 0.324 g of Na.<\/p>\n

STORAGE<\/h2>\n

In an airtight container.<\/p>\n

IMPURITIES<\/h2>\n

Specified impurities A, B, C.<\/p>\n

\"Sodium<\/p>\n

A. (Z)-butenedioic acid (maleic acid),<\/p>\n

\"Sodium<\/p>\n

B. (E)-butenedioic acid (fumaric acid),<\/p>\n

\"Sodium<\/p>\n

C. (2RS)-2-sulfanylbutanedioic acid (thiomalic acid).<\/p>\n","protected":false},"excerpt":{"rendered":"

(Ph. Eur. monograph 1994) Action and use Used in the treatment of rheumatoid arthritis. Preparation Sodium Aurothiomalate Injection DEFINITION Mixture of monosodium and disodium salts of (2RS)-2 (aurosulfanyl)butanedioic acid. Content \u2014 gold (Au; Ar 197.0): 44.5 per cent to 46.0 per cent (dried substance); \u2014 sodium (Na; Ar 22.99): 10.8 per cent to 11.8 per…<\/p>\n","protected":false},"author":2,"featured_media":29940,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-29919","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-medicinal-substances"],"acf":[],"_links":{"self":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/29919","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=29919"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/29919\/revisions"}],"predecessor-version":[{"id":29942,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/29919\/revisions\/29942"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/29940"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=29919"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=29919"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=29919"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}