Action and use<\/strong><\/p>\n Skeletal muscle relaxant.<\/p>\n Preparations<\/strong><\/p>\n Baclofen Oral Solution<\/p>\n Baclofen Tablets<\/p>\n (3RS)-4-Amino-3-(4-chlorophenyl)butanoic acid.<\/p>\n 98.0 per cent to 101.0 per cent (anhydrous substance).<\/p>\n White or almost white powder.<\/p>\n Slightly soluble in water, very slightly soluble in ethanol (96 per cent), practically insoluble in acetone. It dissolves in dilute mineral acids and in dilute solutions of alkali hydroxides.<\/p>\n It shows polymorphism (5.9).<\/p>\n First identification: B.<\/p>\n Second identification: A, C.<\/p>\n A. Ultraviolet and visible absorption spectrophotometry (2.2.25).<\/p>\n Test solution: Dissolve 70 mg in water R and dilute to 100.0 mL with the same solvent.<\/p>\n Spectral range: 220-320 nm.<\/p>\n Absorption maxima: At 259 nm, 266 nm and 275 nm.<\/p>\n Resolution (2.2.25): minimum 1.5 for the absorbance ratio.<\/p>\n Specific absorbance at the absorption maxima:<\/p>\n \u2014 at 259 nm: 9.8 to 10.8;<\/p>\n \u2014 at 266 nm: 11.5 to 12.7;<\/p>\n \u2014 at 275 nm: 8.4 to 9.3.<\/p>\n B. Infrared absorption spectrophotometry (2.2.24).<\/p>\n Preparation: Discs prepared using 3 mg of substance and 300 mg of potassium bromide R.<\/p>\n Comparison baclofen CRS.<\/p>\n If the spectra obtained in the solid state show differences, dissolve 0.1 g of each of the substances separately in 1 mL of dilute sodium hydroxide solution R and add 10 mL of ethanol (96 per cent) R and 1 mL of dilute acetic acid R. Allow to stand for 1 h. Filter, wash the precipitate with ethanol (96 per cent) R and dry in vacuo. Prepare new discs and record the spectra.<\/p>\n C. Thin-layer chromatography (2.2.27).<\/p>\n Test solution: Dissolve 10 mg of the substance to be examined in the mobile phase and dilute to 10 mL with the mobile phase.<\/p>\n Reference solution: Dissolve 10 mg of baclofen CRS in the mobile phase and dilute to 10 mL with the mobile phase.<\/p>\n Plate: TLC silica gel G plate R.<\/p>\n Mobile phase anhydrous formic acid R, water R, methanol R, chloroform R, ethyl acetate R (5:5:20:30:40 V\/V\/V\/V\/V).<\/p>\n Application: 5 \u03bcL.<\/p>\n Development: Over a path of 12 cm.<\/p>\n Drying: Allow the solvents to evaporate.<\/p>\n Detection Spray with ninhydrin solution R3 until the plate is slightly wet. Place in an oven maintained at 100 \u00b0C for 10 min. Examine in daylight.<\/p>\n Results: The principal spot in the chromatogram obtained with the test solution is similar in position, colour and size to the principal spot in the chromatogram obtained with the reference solution.<\/p>\n Appearance of solution<\/p>\n The solution is not more opalescent than reference suspension II (2.2.1) and not more intensely coloured than reference solution BY5 (2.2.2, Method II).<\/p>\n Dissolve 0.50 g in 1 M sodium hydroxide and dilute to 25 mL with the same solvent.<\/p>\n Liquid chromatography (2.2.29).<\/p>\n Test solution: Dissolve 25.0 mg of the substance to be examined in the mobile phase and dilute to 10.0 mL with the mobile phase.<\/p>\n Reference solution (a): Dissolve 25.0 mg of baclofen impurity A CRS in the mobile phase and dilute to 10.0 mL with the mobile phase.<\/p>\n Reference solution (b): Dilute 1.0 mL of reference solution (a) to 100.0 mL with the mobile phase.<\/p>\n Reference solution (c): Dilute 2.0 mL of the test solution to 100.0 mL with the mobile phase.<\/p>\n Reference solution (d): Dilute 2.0 mL of the test solution and 2.0 mL of reference solution (a) to 100.0 mL with the mobile phase.<\/p>\n Column:<\/p>\n \u2014 size: l = 0.25 m, \u00d8 = 4.0 mm;<\/p>\n \u2014 stationary phase: octadecylsilyl silica gel for chromatography R (10 \u03bcm).<\/p>\n Mobile phase: Dissolve 1.822 g of sodium hexanesulfonate R in 1 L of a mixture of 560 volumes of water R, 440 volumes of methanol R and 5 volumes of glacial acetic acid R.<\/p>\n Flow rate: 2.0 mL\/min.<\/p>\n Detection: Spectrophotometer at 266 nm.<\/p>\n Injection: 20 \u03bcL of the test solution and reference solutions (b), (c) and (d).<\/p>\n Run time: 5 times the retention time of baclofen.<\/p>\n System suitability: Reference solution (d):<\/p>\n \u2014 resolution: minimum 2.0 between the peaks due to baclofen and impurity A.<\/p>\n Limits:<\/p>\n \u2014 impurity A: not more than the area of the principal peak in the chromatogram obtained with reference solution (b) (1.0 per cent);<\/p>\n \u2014 total: not more than the area of the principal peak in the chromatogram obtained with reference solution (c) (2.0 percent).<\/p>\n Maximum 1.0 per cent, determined on 1.000 g.<\/p>\n Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n Dissolve 0.1500 g in 50 mL of anhydrous acetic acid R. Titrate with 0.1 M perchloric acid, determining the end-point potentiometrically (2.2.20).<\/p>\n 1 mL of 0.1 M perchloric acid is equivalent to 21.37 mg of C10<\/sub>H12<\/sub>ClNO2<\/sub>.<\/p>\n Specified impurities A.<\/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) B.<\/p>\n A. (4RS)-4-(4-chlorophenyl)pyrrolidin-2-one,<\/p>\n B. (3RS)-5-amino-3-(4-chlorophenyl)-5-oxopentanoic acid.<\/p>\n","protected":false},"excerpt":{"rendered":" (Ph. Eur. monograph 0653) C10H12ClNO2\u00a0 \u00a0213.7\u00a0 \u00a01134-47-0 Action and use Skeletal muscle relaxant. Preparations Baclofen Oral Solution Baclofen Tablets DEFINITION (3RS)-4-Amino-3-(4-chlorophenyl)butanoic acid. Content 98.0 per cent to 101.0 per cent (anhydrous substance). CHARACTERS Appearance White or almost white powder. Solubility Slightly soluble in water, very slightly soluble in ethanol (96 per cent), practically insoluble in…<\/p>\n","protected":false},"author":3,"featured_media":2575,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-2570","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\/2570","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\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=2570"}],"version-history":[{"count":4,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/2570\/revisions"}],"predecessor-version":[{"id":7688,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/2570\/revisions\/7688"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/2575"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=2570"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=2570"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=2570"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}DEFINITION<\/h2>\n
Content<\/h3>\n
CHARACTERS<\/h2>\n
Appearance<\/h3>\n
Solubility<\/h3>\n
IDENTIFICATION<\/h2>\n
TESTS<\/h2>\n
Related substances<\/h3>\n
Water (2.5.12)<\/h4>\n
Sulfated ash (2.4.14)<\/h4>\n
ASSAY<\/h2>\n
IMPURITIES<\/h2>\n
![\"Baclofen-1\"](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/09\/1-146-300x163.jpg\")
<\/p>\n![\"Baclofen-2\"](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/09\/2-192-300x163.jpg\")
<\/p>\n