Action and use<\/strong><\/p>\n Excipient.<\/p>\n (2RS)-2-Hydroxybutanedioic acid.<\/p>\n Content<\/strong><\/p>\n 99.0 per cent to 101.0 per cent (anhydrous substance).<\/p>\n Appearance<\/strong><\/p>\n White or almost white, crystalline powder.<\/p>\n Solubility<\/strong><\/p>\n Freely soluble in water and in ethanol (96 per cent), sparingly soluble in acetone.<\/p>\n A. Melting point (2.2.14): 128 \u00b0C to 132 \u00b0C.<\/p>\n B. Infrared absorption spectrophotometry (2.2.24).<\/p>\n Comparison Ph. Eur. reference spectrum of malic acid.<\/p>\n Solution S<\/strong><\/p>\n Dissolve 5.00 g in water R and dilute to 25 mL with the same solvent.<\/p>\n Appearance of solution<\/strong><\/p>\n Solution S is clear (2.2.1) and colourless (2.2.2, Method II).<\/p>\n Optical rotation (2.2.7)<\/strong><\/p>\n -0.10\u00b0 to + 0.10\u00b0, determined on solution S.<\/p>\n Water-insoluble substances<\/strong><\/p>\n Maximum 0.1 per cent.<\/p>\n Dissolve 25.0 g in 100 mL of water R, filter the solution through a tared sintered-glass filter (16) (2.1.2), wash the filter with hot water R and dry at 100-105 \u00b0C to constant weight. The residue weighs a maximum of 25 mg.<\/p>\n Related substances<\/strong><\/p>\n Liquid chromatography (2.2.29).<\/p>\n Test solution Dissolve 100.0 mg of the substance to be examined in the mobile phase and dilute to 100.0 mL with the mobile phase.<\/p>\n Reference solution (a) Dissolve 10.0 mg of fumaric acid R and 4.0 mg of maleic acid R in 25 mL of the mobile phase and dilute to 50.0 mL with the mobile phase.<\/p>\n Reference solution (b) Dilute 2.5 mL of reference solution (a) to 100.0 mL with the mobile phase.<\/p>\n Reference solution (c) Dissolve 20.0 mg of the substance to be examined in the mobile phase, add 1.0 mL of reference solution (a) and dilute to 20.0 mL with the mobile phase.<\/p>\n Column: Mobile phase 0.005 M sulfuric acid.<\/p>\n Flow rate 0.6 mL\/min.<\/p>\n Detection Spectrophotometer at 210 nm.<\/p>\n Injection 20 \u03bcL.<\/p>\n Run time Twice the retention time of the principal peak in the chromatogram obtained with the test solution.<\/p>\n Relative retention With reference to malic acid (retention time = about 10 min): impurity B = about 0.8; impurity A = about 1.5.<\/p>\n System suitability Reference solution (c): Limits: Water (2.5.12)<\/strong><\/p>\n Maximum 2.0 per cent, determined on 1.00 g.<\/p>\n Sulfated ash (2.4.14)<\/strong><\/p>\n Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n Dissolve 0.500 g in 50 mL of carbon dioxide-free water R. Titrate with 1 M sodium hydroxide determining the end-point potentiometrically (2.2.20).<\/p>\n 1 mL of 1 M sodium hydroxide is equivalent to 67.05 mg of C4<\/sub>H6<\/sub>O5<\/sub><\/p>\n Specified impurities A, B.<\/p>\n A. (E)-butenedioic acid (fumaric acid),<\/span> B. (Z)-butenedioic acid (maleic acid).<\/p>\n","protected":false},"excerpt":{"rendered":" Edition: BP 2025 (Ph. Eur. 11.6 update) General Notices (Ph. Eur. monograph 2080) C4H6O5 134.1 6915-15-7 Action and use Excipient. DEFINITION (2RS)-2-Hydroxybutanedioic acid. Content 99.0 per cent to 101.0 per cent (anhydrous substance). CHARACTERS Appearance White or almost white, crystalline powder. Solubility Freely soluble in water and in ethanol (96 per cent), sparingly soluble in…<\/p>\n","protected":false},"author":5,"featured_media":23502,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-23517","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\/23517","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\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=23517"}],"version-history":[{"count":5,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/23517\/revisions"}],"predecessor-version":[{"id":23549,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/23517\/revisions\/23549"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/23502"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=23517"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=23517"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=23517"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}DEFINITION<\/h2>\n
CHARACTERS<\/h2>\n
IDENTIFICATION<\/h2>\n
TESTS<\/h2>\n
\n\u2014 size: l = 0.30 m, \u00d8 = 7.8 mm,
\n\u2014 stationary phase: ion-exclusion resin for chromatography R (9 \u03bcm),
\n\u2014 temperature: 37 \u00b0C.<\/p>\n
\n\u2014 resolution: minimum 2.5 between the peaks due to impurity B and malic acid.<\/p>\n
\n\u2014 impurity A: not more than twice the area of the corresponding peak in the chromatogram obtained with reference solution (b) (1.0 per cent),
\n\u2014 impurity B: not more than 0.25 times the area of the corresponding peak in the chromatogram obtained with reference solution (b) (0.05 per cent),
\n\u2014 any other impurity: for each impurity, not more than 0.5 times the area of the peak due to impurity B in the chromatogram obtained with reference solution (b) (0.1 per cent),
\n\u2014 total of other impurities: not more than 2.5 times the area of the peak due to impurity B in the chromatogram obtained with reference solution (b) (0.5 per cent),
\n\u2014 disregard limit: 0.1 times the area of the peak due to impurity B in the chromatogram obtained with reference solution (b) (0.02 per cent).<\/p>\nASSAY<\/h2>\n
IMPURITIES<\/h2>\n
![\"fumaric-acid\"](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/fumaric-acid.jpg\")
<\/p>\n![\"maleic-acid\"](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/maleic-acid.jpg\")
<\/p>\n