{"id":26279,"date":"2025-11-05T15:00:47","date_gmt":"2025-11-05T08:00:47","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=26279"},"modified":"2025-11-05T15:00:47","modified_gmt":"2025-11-05T08:00:47","slug":"pentazocine","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/pentazocine\/","title":{"rendered":"Pentazocine"},"content":{"rendered":"<p><em>(Ph. Eur. monograph 1462)<\/em><\/p>\n<p>C<sub>19<\/sub>H<sub>27<\/sub>NO 285.4 359-83-1<\/p>\n<p><strong>Action and use<\/strong><\/p>\n<p>Opioid receptor agonist; analgesic.<\/p>\n<p><strong>Preparation<\/strong><\/p>\n<p>Pentazocine Injection<\/p>\n<h2>DEFINITION<\/h2>\n<p>Pentazocine contains not less than 99.0 per cent and not more than the equivalent of 101.0 per cent of (2RS,6RS,11RS)-6,11-dimethyl-3-(3-methylbut-2-enyl)-1,2,3,4,5,6-hexahydro-2,6-methano-3-benzazocin-8-ol, calculated with reference to the dried substance.<\/p>\n<h2>CHARACTERS<\/h2>\n<p>A white or almost white powder, practically insoluble in water, freely soluble in methylene chloride and soluble in ethanol (96 per cent).<\/p>\n<p>It shows polymorphism (5.9).<\/p>\n<h2>IDENTIFICATION<\/h2>\n<p>Examine by infrared absorption spectrophotometry (2.2.24), comparing with the Ph. Eur. reference spectrum for pentazocine (form A).<\/p>\n<h2>TESTS<\/h2>\n<h3>Absorbance (2.2.25)<\/h3>\n<p>Dissolve 0.100 g in a mixture of 20 mL of water R and 1 mL of 1 M hydrochloric acid, and dilute to 100.0 mL with water R.<\/p>\n<p>To 10.0 mL add 1 mL of 1 M hydrochloric acid and dilute to 100.0 mL with water R. The absorbance at the absorption maximum at 278 nm is 0.67 to 0.71, calculated with reference to the dried substance.<\/p>\n<h3>Related substances<\/h3>\n<p>Examine by thin-layer chromatography (2.2.27), using a TLC silica gel F254 plate R.<\/p>\n<p>Test solution: Dissolve 0.20 g of the substance to be examined in methylene chloride R and dilute to 10 mL with the same solvent.<\/p>\n<p>Reference solution (a): Dilute 1 mL of the test solution to 100 mL with methylene chloride R.<\/p>\n<p>Reference solution (b): Dilute 5 mL of reference solution (a) to 10 mL with methylene chloride R.<\/p>\n<p>Reference solution (c): Dilute 5 mL of reference solution (a) to 20 mL with methylene chloride R.<\/p>\n<p>Apply to the plate 10 \u03bcL of each solution. Develop over a path corresponding to two thirds of the plate height using a mixture of 3 volumes of isopropylamine R, 3 volumes of methanol R and 94 volumes of methylene chloride R. Allow the plate to dry in air and examine in ultraviolet light at 254 nm. Heat the plate at 100-105 \u00b0C for 15 min, allow to cool, expose to iodine vapour and re-examine under ultraviolet light at 254 nm. By each method of visualisation: any spot in the chromatogram obtained with the test solution, apart from the principal spot, is not more intense than the spot obtained with reference solution (a) (1 per cent); not more than one such spot is more intense than the spot in the chromatogram obtained with reference solution (b) (0.5 per cent) and not more than 4 such spots are more intense than the spot in the chromatogram obtained with reference solution (c) (0.25 per cent).<\/p>\n<h3>Loss on drying (2.2.32)<\/h3>\n<p>Not more than 0.5 per cent, determined on 1.000 g by drying at 60 \u00b0C at a pressure not exceeding 0.7 kPa for 4 h.<\/p>\n<h3>Sulfated ash (2.4.14)<\/h3>\n<p>Not more than 0.1 per cent, determined on 1.0 g.<\/p>\n<h2>ASSAY<\/h2>\n<p>Dissolve 0.200 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<p>1 mL of 0.1 M perchloric acid is equivalent to 28.54 mg of C<sub>19<\/sub>H<sub>27<\/sub>NO.<\/p>\n<h2>STORAGE<\/h2>\n<p>Store protected from light.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>(Ph. Eur. monograph 1462) C19H27NO 285.4 359-83-1 Action and use Opioid receptor agonist; analgesic. Preparation Pentazocine Injection DEFINITION Pentazocine contains not less than 99.0 per cent and not more than the equivalent of 101.0 per cent of (2RS,6RS,11RS)-6,11-dimethyl-3-(3-methylbut-2-enyl)-1,2,3,4,5,6-hexahydro-2,6-methano-3-benzazocin-8-ol, calculated with reference to the dried substance. CHARACTERS A white or almost white powder, practically insoluble in&#8230;<\/p>\n","protected":false},"author":4,"featured_media":26281,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-26279","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\/26279","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=26279"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/26279\/revisions"}],"predecessor-version":[{"id":26283,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/26279\/revisions\/26283"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/26281"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=26279"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=26279"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=26279"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}