98.0 per cent to 101.0 per cent (anhydrous substance).<\/p>\n
CHARACTERS<\/h2>\nAppearance<\/h3>\n
White or almost white, crystalline powder.<\/p>\n
Solubility<\/h3>\n
Slightly soluble in water, freely soluble in methanol, slightly soluble in anhydrous ethanol.<\/p>\n
IDENTIFICATION<\/h2>\n
A. Infrared absorption spectrophotometry (2.2.24).<\/p>\n
Comparison\u00a0 dembrexine hydrochloride monohydrate CRS.<\/p>\n
B. It gives reaction (a) of chlorides (2.3.1).<\/p>\n
TESTS<\/h2>\nRelated substances<\/h3>\n
Liquid chromatography (2.2.29). Prepare the solutions immediately before use.<\/p>\n
Test solution Dissolve 25.0 mg of the substance to be examined in methanol R and dilute to 10.0 mL with the same solvent.<\/p>\n
Reference solution (a)\u00a0 Dilute 1.0 mL of the test solution to 50.0 mL with methanol R. Dilute 1.0 mL of this solution to
\n10.0 mL with methanol R.<\/p>\n
Reference solution (b) Dissolve 2.5 mg of tribromophenol R (impurity E) in methanol R and dilute to 50.0 mL with the same solvent. To 1.0 mL of this solution add 1.0 mL of the test solution and dilute to 10.0 mL with methanol R.<\/p>\n
Blank solution Methanol R. Column:<\/p>\n
\u2014 size: l = 0.15 m, \u00d8 = 4.0 mm;<\/p>\n
\u2014 stationary phase: end-capped octadecylsilyl silica gel for chromatography R (5 \u00b5m);<\/p>\n
\u2014 temperature: 40 \u00b0C.<\/p>\n
Mobile phase:<\/p>\n
\u2014 mobile phase A: dissolve 1.0 g of potassium dihydrogen phosphate R in 900 mL of water R, adjust to pH 7.4 with a
\n0.5 M potassium hydroxide solution prepared from potassium hydroxide R and dilute to 1000 mL with water R; mix 80 volumes of this solution with 20 volumes of methanol R;<\/p>\n
\u2014 mobile phase B: methanol R, acetonitrile R (20:80 V\/V);<\/p>\n
Time (min)<\/strong><\/td>\n| Mobile phase A (per cent V\/V)<\/strong><\/td>\n | Mobile phase B (per cent V\/V)<\/strong><\/td>\n<\/tr>\n | 0 – 7<\/td>\n | 75<\/td>\n | 25<\/td>\n<\/tr>\n | 7 – 15<\/td>\n | 75 \u2192 50<\/td>\n | 25 \u2192 50<\/td>\n<\/tr>\n | 15 – 20<\/td>\n | 50<\/td>\n | 50<\/td>\n<\/tr>\n | 20 – 25<\/td>\n | 50 \u2192 75<\/td>\n | 50 \u2192 25<\/td>\n<\/tr>\n | 25 – 30<\/td>\n | 75<\/td>\n | 75<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n | Flow rate\u00a0 1.0 mL\/min.<\/p>\n Detection\u00a0 Spectrophotometer at 250 nm.<\/p>\n Injection\u00a0 10 \u00b5L.<\/p>\n Relative retention With reference to dembrexine (retention time = about 6 min): impurity A = about 2.3; impurity B = about 1.3.<\/p>\n System suitability\u00a0 Reference solution (b):<\/p>\n \u2014 resolution: minimum 2 between the peaks due to dembrexine and impurity E.<\/p>\n Limits:<\/p>\n \u2014 impurities A, B: for each impurity, not more than the area of the principal peak in the chromatogram obtained with reference solution (a) (0.2 per cent);<\/p>\n \u2014 unspecified impurities: for each impurity, not more than the area of the principal peak in the chromatogram obtained with reference solution (a) (0.2 per cent);<\/p>\n \u2014 total: not more than 2.5 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.5 per cent);<\/p>\n \u2014 disregard limit: 0.5 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.1 per cent).<\/p>\n Water (2.5.12)<\/h3>\n3.5 per cent to 5.0 per cent, determined on 0.500 g.<\/p>\n Sulfated ash (2.4.14)<\/h3>\nMaximum 0.1 per cent, determined on 1.0 g.<\/p>\n ASSAY<\/h2>\nDissolve 0.350 g in 40 mL of methanol R. Add 40 mL of acetone R and 1 mL of 0.1 M hydrochloric acid. Carry out a potentiometric titration (2.2.20) using 0.1 M sodium hydroxide. Read the volume added between the 2 points of inflexion.<\/p>\n 1 mL of 0.1 M sodium hydroxide is equivalent to 41.56 mg of C13<\/sub>H18<\/sub>Br2<\/sub>ClNO2<\/sub>.<\/p>\n Specified impurities\u00a0 A, B.<\/em><\/p>\n Other detectable impurities (the following substances would, if present at a sufficient level, be detected by one or other of the tests in the monograph. They are limited by the general acceptance criterion for other\/unspecified impurities and\/or by the general monograph Substances for pharmaceutical use (2034). It is therefore not necessary to identify these impurities for demonstration of compliance. See also 5.10. Control of impurities in substances for pharmaceutical use) C, D, E.<\/em><\/p>\n A. trans-4-[(3,5-dibromo-2-hydroxybenzylidene)amino]cyclohexanol,<\/p>\n B. cis-4-[(3,5-dibromo-2-hydroxybenzyl)amino]cyclohexanol,<\/p>\n C. 3,5-dibromo-2-hydroxybenzaldehyde,<\/p>\n D. 2-hydroxybenzaldehyde (salicylaldehyde),<\/p>\n E. 2,4,6-tribromophenol.<\/p>\n","protected":false},"excerpt":{"rendered":" Edition: BP 2025 (Ph. Eur. 11.6 update) DEFINITION trans-4-[(3,5-Dibromo-2-hydroxybenzyl)amino]cyclohexanol hydrochloride monohydrate. Content 98.0 per cent to 101.0 per cent (anhydrous substance). CHARACTERS Appearance White or almost white, crystalline powder. Solubility Slightly soluble in water, freely soluble in methanol, slightly soluble in anhydrous ethanol. IDENTIFICATION A. Infrared absorption spectrophotometry (2.2.24). Comparison\u00a0 dembrexine hydrochloride monohydrate CRS. B….<\/p>\n","protected":false},"author":5,"featured_media":23395,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[176],"tags":[],"class_list":["post-23394","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-british-pharmacopoeia-veterinary-2020"],"acf":[],"_links":{"self":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/23394","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=23394"}],"version-history":[{"count":4,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/23394\/revisions"}],"predecessor-version":[{"id":23452,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/23394\/revisions\/23452"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/23395"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=23394"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=23394"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=23394"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}} |
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