{"id":10788,"date":"2025-10-08T14:42:55","date_gmt":"2025-10-08T07:42:55","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=10788"},"modified":"2025-10-08T14:42:55","modified_gmt":"2025-10-08T07:42:55","slug":"clenbuterol-hydrochloride","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/clenbuterol-hydrochloride\/","title":{"rendered":"Clenbuterol Hydrochloride"},"content":{"rendered":"<p>(Ph. Eur. monograph 1409)<\/p>\n<p>C<sub>12<\/sub>H<sub>19<\/sub>Cl<sub>3<\/sub>N<sub>2<\/sub>O 313.7 21898-19-1<\/p>\n<p><strong>Action and use<\/strong><\/p>\n<p>Beta<sub>2<\/sub>-adrenoceptor agonist; bronchodilator.<\/p>\n<p><strong>Preparations<\/strong><\/p>\n<p>Clenbuterol Granules (VET)<\/p>\n<p>Clenbuterol Injection (VET)<\/p>\n<p>Clenbuterol Oral Solution (VET)<\/p>\n<h2>DEFINITION<\/h2>\n<p>(1RS)-1-(4-Amino-3,5-dichlorophenyl)-2-[(1,1-dimethylethyl)amino]ethanol hydrochloride.<\/p>\n<h3>Content<\/h3>\n<p>99.0 per cent to 101.0 per cent (anhydrous substance).<\/p>\n<h2>CHARACTERS<\/h2>\n<h3>Appearance<\/h3>\n<p>White or almost white, crystalline powder.<\/p>\n<h3>Solubility<\/h3>\n<p>Soluble in water and in ethanol (96 per cent), slightly soluble in acetone.<\/p>\n<h3>mp<\/h3>\n<p>About 173 \u00b0C, with decomposition.<\/p>\n<h2>IDENTIFICATION<\/h2>\n<p>First identification: A, C.<\/p>\n<p>Second identification: B, C.<\/p>\n<p>A. Infrared absorption spectrophotometry (2.2.24).<\/p>\n<p>Comparison: clenbuterol hydrochloride CRS.<\/p>\n<p>B. Thin-layer chromatography (2.2.27).<\/p>\n<p>Test solution: Dissolve 10 mg of the substance to be examined in 10 mL of methanol R.<\/p>\n<p>Reference solution: Dissolve 10 mg of clenbuterol hydrochloride CRS in 10 mL of methanol R.<\/p>\n<p>Plate: TLC silica gel F254 plate R.<\/p>\n<p>Mobile phase: ammonia R, anhydrous ethanol R, toluene R (0.15:10:15 V\/V\/V).<\/p>\n<p>Application: 10 \u03bcL.<\/p>\n<p>Development: Over a path of 10 cm.<\/p>\n<p>Drying: In air.<\/p>\n<p>Detection: Spray with a 10 g\/L solution of sodium nitrite R in 1 M hydrochloric acid and dip after 10 min in a 4 g\/L solution of naphthylethylenediamine dihydrochloride R in methanol R. Allow to dry in air.<\/p>\n<p>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<p>C. It gives reaction (a) of chlorides (2.3.1).<\/p>\n<h2>TESTS<\/h2>\n<h3>Solution S<\/h3>\n<p>Dissolve 0.5 g in 10 mL of carbon dioxide-free water R.<\/p>\n<h3>Appearance of solution<\/h3>\n<p>Solution S is not more opalescent than reference suspension II (2.2.1) and not more intensely coloured than reference solution Y6 (2.2.2, Method II).<\/p>\n<h3>pH (2.2.3)<\/h3>\n<p>5.0 to 7.0 for solution S.<\/p>\n<h3>Optical rotation (2.2.7)<\/h3>\n<p>-0.10\u00b0 to + 0.10\u00b0.<\/p>\n<p>Dissolve 0.30 g in water R and dilute to 10.0 mL with the same solvent. Filter if necessary.<\/p>\n<h3>Related substances<\/h3>\n<p>Liquid chromatography (2.2.29).<\/p>\n<p>Test solution: Disperse 100.0 mg of the substance to be examined in the mobile phase and dilute to 50.0 mL with the mobile phase.<\/p>\n<p>Reference solution (a): Dilute 0.1 mL of the test solution to 100.0 mL with water R.<\/p>\n<p>Reference solution (b): Dissolve 5 mg of clenbuterol impurity B CRS in 10 mL of the mobile phase, add 2.5 mL of the test solution and dilute to 25.0 mL with the mobile phase.<\/p>\n<p>Column:<\/p>\n<p>\u2014 size: l = 0.125 m, \u00d8 = 4 mm,<\/p>\n<p>\u2014 stationary phase: end-capped octadecylsilyl silica gel for chromatography R (5 \u03bcm),<\/p>\n<p>\u2014 temperature: 40 \u00b0C.<\/p>\n<p>Mobile phase: Mix 200 volumes of acetonitrile R, 200 volumes of methanol R and 600 volumes of a solution prepared as follows: dissolve 3.0 g of sodium decanesulfonate R and 5.0 g of potassium dihydrogen phosphate R in 900 mL of water R, adjust to pH 3.0 with dilute phosphoric acid R and dilute to 1000 mL with water R.<\/p>\n<p>Flow rate: 0.5 mL\/min.<\/p>\n<p>Detection: Spectrophotometer at 215 nm.<\/p>\n<p>Injection: 5 \u03bcL.<\/p>\n<p>Run time: 1.5 times the retention time of clenbuterol.<\/p>\n<p>Retention time: Clenbuterol = about 29 min.<\/p>\n<p>System suitability: Reference solution (b):<\/p>\n<p>\u2014 resolution: minimum 4.0 between the peaks due to impurity B and clenbuterol.<\/p>\n<p>Limits:<\/p>\n<p>\u2014 impurities A, B, C, D, E, F: for each impurity, not more than the area of the principal peak in the chromatogram obtained with reference solution (a) (0.1 per cent),<\/p>\n<p>\u2014 any other impurity: for each impurity, not more than the area of the principal peak in the chromatogram obtained with reference solution (a) (0.1 per cent),<\/p>\n<p>\u2014 total: not more than twice the area of the principal peak in the chromatogram obtained with reference solution (a) (0.2 per cent),<\/p>\n<p>\u2014 disregard limit: 0.5 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.05 per cent).<\/p>\n<h3>Water (2.5.12)<\/h3>\n<p>Maximum 1.0 per cent, determined on 0.500 g.<\/p>\n<h3>Sulfated ash (2.4.14)<\/h3>\n<p>Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n<h2>ASSAY<\/h2>\n<p>Dissolve 0.250 g in 50 mL of ethanol (96 per cent) R and add 5.0 mL of 0.01 M hydrochloric acid. Titrate with 0.1 M sodium hydroxide, determining the end-point potentiometrically (2.2.20). Read the volume added between the 2 points of inflexion.<\/p>\n<p>1 mL of 0.1 M sodium hydroxide is equivalent to 31.37 mg of C<sub>12<\/sub>H<sub>19<\/sub>Cl<sub>3<\/sub>N<sub>2<\/sub>O.<\/p>\n<h3>IMPURITIES<\/h3>\n<p>Specified impurities A, B, C, D, E, F.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-10820\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/2-68-300x163.jpg\" alt=\"Clenbuterol Hydrochloride\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/2-68-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/2-68-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/2-68-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/2-68.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>A. 4-amino-3,5-dichlorobenzaldehyde,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-10821\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/3-62-300x163.jpg\" alt=\"Clenbuterol Hydrochloride\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/3-62-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/3-62-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/3-62-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/3-62.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>B. 1-(4-amino-3,5-dichlorophenyl)-2-[(1,1-dimethylethyl)amino]ethanone,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-10822\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/4-55-300x163.jpg\" alt=\"Clenbuterol Hydrochloride\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/4-55-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/4-55-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/4-55-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/4-55.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>C. 1-(4-amino-3,5-dichlorophenyl)ethanone,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-10823\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/5-43-300x163.jpg\" alt=\"Clenbuterol Hydrochloride\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/5-43-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/5-43-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/5-43-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/5-43.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>D. 1-(4-aminophenyl)ethanone,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-10824\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/6-37-300x163.jpg\" alt=\"Clenbuterol Hydrochloride\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/6-37-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/6-37-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/6-37-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/6-37.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>E. 1-(4-amino-3,5-dichlorophenyl)-2-bromoethanone,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-10825\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/7-30-300x163.jpg\" alt=\"Clenbuterol Hydrochloride\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/7-30-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/7-30-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/7-30-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/7-30.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>F. (1RS)-1-(4-amino-3-bromo-5-chlorophenyl)-2-[(1,1-dimethylethyl)amino]ethanol.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>(Ph. Eur. monograph 1409) C12H19Cl3N2O 313.7 21898-19-1 Action and use Beta2-adrenoceptor agonist; bronchodilator. Preparations Clenbuterol Granules (VET) Clenbuterol Injection (VET) Clenbuterol Oral Solution (VET) DEFINITION (1RS)-1-(4-Amino-3,5-dichlorophenyl)-2-[(1,1-dimethylethyl)amino]ethanol hydrochloride. Content 99.0 per cent to 101.0 per cent (anhydrous substance). CHARACTERS Appearance White or almost white, crystalline powder. Solubility Soluble in water and in ethanol (96 per cent),&#8230;<\/p>\n","protected":false},"author":4,"featured_media":10819,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-10788","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\/10788","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\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=10788"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/10788\/revisions"}],"predecessor-version":[{"id":10832,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/10788\/revisions\/10832"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/10819"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=10788"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=10788"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=10788"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}