{"id":24833,"date":"2025-11-03T16:25:38","date_gmt":"2025-11-03T09:25:38","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=24833"},"modified":"2025-11-03T17:30:47","modified_gmt":"2025-11-03T10:30:47","slug":"pimobendan","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/pimobendan\/","title":{"rendered":"Pimobendan"},"content":{"rendered":"<p>Edition: BP 2025 (Ph. Eur. 11.6 update)<\/p>\n<p><strong>Action and use<\/strong><\/p>\n<p>Inhibitor of phosphodiesterase type III; calcium sensitizer.<\/p>\n<p><strong>Preparation <\/strong><\/p>\n<p>Pimobendan Capsules<\/p>\n<hr \/>\n<p>Ph Eur<\/p>\n<h2>DEFINITION<\/h2>\n<p>(5RS)-6-[2-(4-Methoxyphenyl)-1H-benzimidazol-5-yl]-5-methyl-4,5-dihydropyridazin-3(2H)-one.<\/p>\n<p>Content<\/p>\n<p>98.0 per cent to 101.0 per cent (anhydrous substance).<\/p>\n<h2>CHARACTERS<\/h2>\n<h3>Appearance<\/h3>\n<p>White or slightly yellowish, hygroscopic powder.<\/p>\n<h3>Solubility<\/h3>\n<p>Practically insoluble in water, freely soluble in dimethylformamide, slightly soluble in acetone and in methanol.<\/p>\n<h3>mp<\/h3>\n<h2>About 242 \u00b0C.<\/h2>\n<p>IDENTIFICATION<\/p>\n<p>Infrared absorption spectrophotometry (2.2.24).<\/p>\n<p>Comparison\u00a0 pimobendan CRS.<\/p>\n<h2>TESTS<\/h2>\n<h3>Related substances<\/h3>\n<p>Liquid chromatography (2.2.29).<\/p>\n<p><em>Test solution<\/em>\u00a0 Dissolve 50 mg of the substance to be examined in methanol R and dilute to 10.0 mL with the same solvent.<\/p>\n<p><em>Reference solution (a)<\/em>\u00a0 Dilute 1.0 mL of the test solution to 100.0 mL with methanol R. Dilute 2.0 mL of this solution to<br \/>\n10.0 mL with methanol R.<\/p>\n<p><em>Reference solution (b)<\/em> Dissolve the contents of a vial of pimobendan for system suitability CRS (containing impurities A and B) in 1 mL of methanol R.<\/p>\n<p><em>Column:<\/em><\/p>\n<p style=\"padding-left: 40px;\"><em>\u2014 size: l<\/em> = 0.125 m, \u00d8 = 4.6 mm;<\/p>\n<p style=\"padding-left: 40px;\"><em>\u2014 stationary phase:<\/em> base-deactivated end-capped octadecylsilyl silica gel for chromatography R (5 \u00b5m);<\/p>\n<p style=\"padding-left: 40px;\"><em>\u2014 temperature:<\/em> 45 \u00b0C.<\/p>\n<p><em>Mobile phase:<\/em><\/p>\n<p><em>\u2014 mobile phase A:<\/em> dissolve 3.0 g of potassium dihydrogen phosphate R in 950 mL of water for chromatography R, adjust to pH 2.5 with dilute phosphoric acid R and dilute to 1000 mL with water for chromatography R;<\/p>\n<p><em>\u2014 mobile phase B:<\/em> acetonitrile R;<\/p>\n<table style=\"border-collapse: collapse; width: 100%;\">\n<tbody>\n<tr>\n<td style=\"width: 33.3333%; text-align: center;\"><strong>Time (min)<\/strong><\/td>\n<td style=\"width: 33.3333%; text-align: center;\"><strong>Mobile phase A (per cent V\/V)<\/strong><\/td>\n<td style=\"width: 33.3333%; text-align: center;\"><strong>Mobile phase B (per cent V\/V)<\/strong><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 33.3333%; text-align: center;\">0 &#8211; 6<\/td>\n<td style=\"width: 33.3333%; text-align: center;\">85 \u2192 80<\/td>\n<td style=\"width: 33.3333%; text-align: center;\">15 \u2192 20<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 33.3333%; text-align: center;\">6 &#8211; 20<\/td>\n<td style=\"width: 33.3333%; text-align: center;\">80 \u2192 20<\/td>\n<td style=\"width: 33.3333%; text-align: center;\">20 \u2192 80<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><em>Flow rate<\/em>\u00a0 1 mL\/min.<\/p>\n<p><em>Detection<\/em>\u00a0 Spectrophotometer at 290 nm.<\/p>\n<p><em>Injection<\/em>\u00a0 10 \u00b5L.<\/p>\n<p><em>Identification of impurities<\/em> Use the chromatogram obtained with reference solution (b) to identify the peaks due to impurities A and B.<\/p>\n<p><em>Relative retention<\/em> With reference to pimobendan (retention time = about 8.3 min): impurity A = about 1.3; impurity B = about 1.4.<\/p>\n<p><em>System suitability<\/em>\u00a0 Reference solution (b):<\/p>\n<p style=\"padding-left: 40px;\"><em>\u2014 resolution:<\/em> minimum 2.0 between the peaks due to impurities A and B.<\/p>\n<p><em>Limits:<\/em><\/p>\n<p style=\"padding-left: 40px;\"><em>\u2014 unspecified impurities:<\/em> for each impurity, not more than the area of the principal peak in the chromatogram obtained with reference solution (a) (0.20 per cent);<\/p>\n<p style=\"padding-left: 40px;\"><em>\u2014 total:<\/em> not more than the area of the principal peak in the chromatogram obtained with reference solution (a) (0.2 per cent);<\/p>\n<p style=\"padding-left: 40px;\"><em>\u2014 disregard limit:<\/em> 0.5 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.10 per cent).<\/p>\n<p><strong>Water (2.5.12)<\/strong><\/p>\n<p>Maximum 1.0 per cent, determined on 0.500 g.<\/p>\n<p><strong>Sulfated ash (2.4.14)<\/strong><\/p>\n<p>Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n<h2>ASSAY<\/h2>\n<p>Dissolve 0.250 g in 5 mL of anhydrous formic acid R. Add 10 mL of acetic anhydride R and 70 mL of anhydrous acetic acid R. Titrate with 0.1 M perchloric acid, determining the end-point potentiometrically (2.2.20).<\/p>\n<p>1 mL of 0.1 M perchloric acid is equivalent to 33.44 mg of C<sub>19<\/sub>H<sub>18<\/sub>N<sub>4<\/sub>O<sub>2<\/sub>.<\/p>\n<h2>STORAGE<\/h2>\n<p>In an airtight container.<\/p>\n<h2>IMPURITIES<\/h2>\n<p><em>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) A, B.<\/em><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-25085\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Pimobendan-British-Pharmacopoeia-2025-1.jpg\" alt=\"Pimobendan\" width=\"1200\" height=\"650\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Pimobendan-British-Pharmacopoeia-2025-1.jpg 1200w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Pimobendan-British-Pharmacopoeia-2025-1-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Pimobendan-British-Pharmacopoeia-2025-1-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Pimobendan-British-Pharmacopoeia-2025-1-768x416.jpg 768w\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" \/><\/p>\n<p>A. (3RS)-4-[2-(4-methoxyphenyl)-1H-benzimidazol-5-yl]-3-methyl-4-oxobutanoic acid,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-25086\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Pimobendan-British-Pharmacopoeia-2025-2.jpg\" alt=\"Pimobendan\" width=\"1200\" height=\"650\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Pimobendan-British-Pharmacopoeia-2025-2.jpg 1200w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Pimobendan-British-Pharmacopoeia-2025-2-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Pimobendan-British-Pharmacopoeia-2025-2-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Pimobendan-British-Pharmacopoeia-2025-2-768x416.jpg 768w\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" \/><\/p>\n<p>B. N-[2-amino-4-[(4RS)-4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl]phenyl]-4-methoxybenzamide.<\/p>\n<hr \/>\n<p>Ph Eur<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Edition: BP 2025 (Ph. Eur. 11.6 update) Action and use Inhibitor of phosphodiesterase type III; calcium sensitizer. Preparation Pimobendan Capsules Ph Eur DEFINITION (5RS)-6-[2-(4-Methoxyphenyl)-1H-benzimidazol-5-yl]-5-methyl-4,5-dihydropyridazin-3(2H)-one. Content 98.0 per cent to 101.0 per cent (anhydrous substance). CHARACTERS Appearance White or slightly yellowish, hygroscopic powder. Solubility Practically insoluble in water, freely soluble in dimethylformamide, slightly soluble in acetone&#8230;<\/p>\n","protected":false},"author":5,"featured_media":24834,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[176],"tags":[],"class_list":["post-24833","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\/24833","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=24833"}],"version-history":[{"count":3,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/24833\/revisions"}],"predecessor-version":[{"id":25087,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/24833\/revisions\/25087"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/24834"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=24833"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=24833"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=24833"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}