Edition: BP 2025 (Ph. Eur. 11.6 update)<\/p>\n
Action and use<\/strong><\/p>\n Alpha2-adrenoceptor antagonist.<\/p>\n Methyl 17\u03b1-hydroxyyohimban-16\u03b1-carboxylate hydrochloride.<\/p>\n Content<\/strong><\/p>\n 97.0 per cent to 102.0 per cent (dried substance).<\/p>\n White or slightly yellowish, crystalline powder.<\/p>\n Sparingly soluble in water, practically insoluble in ethanol (96 per cent) and in methylene chloride.<\/p>\n A. Infrared absorption spectrophotometry (2.2.24).<\/p>\n Comparison\u00a0 yohimbine hydrochloride CRS.<\/p>\n B. It gives reaction (a) of chlorides (2.3.1).<\/p>\n Dissolve 0.500 g in carbon dioxide-free water R with heating, allow to cool to room temperature and dilute to 50.0 mL with the same solvent.<\/p>\n pH (2.2.3)<\/strong><\/p>\n 3.5 to 5.5 for solution S.<\/p>\n Specific optical rotation (2.2.7)<\/strong><\/p>\n + 101.0 to + 105.0 (dried substance), determined on solution S.<\/p>\n Liquid chromatography (2.2.29). Prepare the solutions protected from light.<\/p>\n Test solution Dissolve 10.0 mg of the substance to be examined in methanol R and dilute to 50.0 mL with the same solvent.<\/p>\n Reference solution (a)\u00a0 Dissolve 5 mg of yohimbine for system suitability CRS (containing impurities A, F and G) in Reference solution (b) Dilute 1.0 mL of the test solution to 100.0 mL with methanol R. Reference solution (c) Dilute 1.0 mL of reference solution (b) to 10.0 mL with methanol R.<\/p>\n Reference solution (d) Dissolve 5.0 mg of yohimbine hydrochloride CRS in methanol R and dilute to 25.0 mL with the same solvent.<\/p>\n Column:<\/p>\n \u2014 size: l = 0.125 m, \u00d8 = 4.0 mm;<\/p>\n \u2014 stationary phase: octylsilyl silica gel for chromatography R (4 \u00b5m);<\/p>\n \u2014 temperature: 40 \u00b0C.<\/p>\n Mobile phase Mix 50 mL of a 9.08 g\/L solution of potassium dihydrogen phosphate R, 100 mL of an 11.88 g\/L solution of disodium hydrogen phosphate dihydrate R, 285 mL of acetonitrile for chromatography R, 4.0 g of sodium laurilsulfate R and 355 mL of water for chromatography R.<\/p>\n Flow rate\u00a0 1.5 mL\/min.<\/p>\n Detection\u00a0 Spectrophotometer at 229 nm.<\/p>\n Injection\u00a0 10 \u00b5L of the test solution and of reference solutions (a) (b) and (c).<\/p>\n Run time\u00a0 3 times the retention time of yohimbine.<\/p>\n Identification of impurities Use the chromatogram supplied with yohimbine for system suitability CRS and the chromatogram obtained with reference solution (a) to identify the peaks due to impurities A, F and G.<\/p>\n Relative retention With reference to yohimbine (retention time = about 7 min): impurity F = about 0.65; impurity G = about 0.70; impurity A = about 0.75.<\/p>\n System suitability\u00a0 Reference solution (a):<\/p>\n \u2014 peak-to-valley ratio: minimum 1.3, where Hp = height above the baseline of the peak due to impurity G and<\/p>\n Hv = height above the baseline of the lowest point of the curve separating this peak from the peak due to impurity A; minimum 1.3, where Hp = height above the baseline of the peak due to impurity G and Hv = height above the baseline of the lowest point of the curve separating this peak from the peak due to impurity F.<\/p>\n Limits:<\/p>\n \u2014 sum of impurities A and G: not more than the area of the principal peak in the chromatogram obtained with reference solution (b) (1.0 per cent);<\/p>\n \u2014 impurity F: not more than 4 times the area of the principal peak in the chromatogram obtained with reference solution (c) (0.4 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 (c) (0.10 per cent);<\/p>\n \u2014 total: not more than twice the area of the principal peak in the chromatogram obtained with reference solution (b) (2.0 per cent);<\/p>\n \u2014 disregard limit: 0.5 times the area of the principal peak in the chromatogram obtained with reference solution (c) (0.05 per cent).<\/p>\n Loss on drying (2.2.32)<\/strong><\/p>\n Maximum 0.5 per cent, determined on 1.000 g by drying in an oven at 105 \u00b0C.<\/p>\n Sulfated ash (2.4.14)<\/strong><\/p>\n Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n Liquid chromatography (2.2.29) as described in the test for related substances with the following modification.<\/p>\n Injection\u00a0 Test solution and reference solution (d).<\/p>\n Calculate the percentage content of C21<\/sub>H27<\/sub>ClN2<\/sub>O3<\/sub> taking into account the assigned content of yohimbine hydrochloride CRS.<\/p>\n In an airtight container, protected from light.<\/p>\n Specified impurities\u00a0 A, F, G.<\/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) B, C, D, E.<\/em><\/p>\n A. methyl 17\u03b2-hydroxyyohimban-16\u03b1-carboxylate (\u03b2-yohimbine),<\/p>\n B. methyl 17\u03b1-hydroxy-20\u03b1-yohimban-16\u03b2-carboxylate (\u03b1-yohimbine),<\/p>\n C. methyl 17\u03b1-hydroxyyohimban-16\u03b2-carboxylate (corynantheine),<\/p>\n D. methyl 17\u03b1-hydroxy-3\u03b2-yohimban-16\u03b1-carboxylate (pseudo-yohimbine),<\/p>\n E. methyl (2Z)-2-[(2S,3R,12bS)-3-ethyl-1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]quinolizin-2-yl]-3-methoxyprop-2- enoate,<\/p>\n F. unknown structure,<\/p>\n G. unknown structure.<\/p>\n","protected":false},"excerpt":{"rendered":" Edition: BP 2025 (Ph. Eur. 11.6 update) Action and use Alpha2-adrenoceptor antagonist. DEFINITION Methyl 17\u03b1-hydroxyyohimban-16\u03b1-carboxylate hydrochloride. Content 97.0 per cent to 102.0 per cent (dried substance). CHARACTERS Appearance White or slightly yellowish, crystalline powder. Solubility Sparingly soluble in water, practically insoluble in ethanol (96 per cent) and in methylene chloride. IDENTIFICATION A. Infrared absorption spectrophotometry…<\/p>\n","protected":false},"author":5,"featured_media":31653,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-31652","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\/31652","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=31652"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/31652\/revisions"}],"predecessor-version":[{"id":31656,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/31652\/revisions\/31656"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/31653"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=31652"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=31652"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=31652"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}DEFINITION<\/h2>\n
CHARACTERS<\/h2>\n
Appearance<\/h3>\n
Solubility<\/h3>\n
IDENTIFICATION<\/h2>\n
TESTS<\/h2>\n
Solution S<\/h3>\n
Related substances<\/h3>\n
\nmethanol R and dilute to 25 mL with the same solvent.<\/p>\nASSAY<\/h2>\n
STORAGE<\/h2>\n
IMPURITIES<\/h2>\n