{"id":11825,"date":"2025-10-10T09:59:26","date_gmt":"2025-10-10T02:59:26","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=11825"},"modified":"2025-10-10T09:59:26","modified_gmt":"2025-10-10T02:59:26","slug":"demeclocycline-hydrochloride","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/demeclocycline-hydrochloride\/","title":{"rendered":"Demeclocycline Hydrochloride"},"content":{"rendered":"<p>(Ph. Eur. monograph 0176)<\/p>\n<p>C<sub>21<\/sub>H<sub>22<\/sub>Cl<sub>2<\/sub>N<sub>2<\/sub>O<sub>8<\/sub> 501.3 64-73-3<\/p>\n<p><strong>Action and use<\/strong><\/p>\n<p>Tetracycline antibacterial.<\/p>\n<p><strong>Preparation<\/strong><\/p>\n<p>Demeclocycline Capsules<\/p>\n<h2>DEFINITION<\/h2>\n<p>(4S,4aS,5aS,6S,12aS)-7-Chloro-4-(dimethylamino)-3,6,10,12,12a-pentahydroxy-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide hydrochloride.<\/p>\n<p>Substance produced by certain strains of Streptomyces aureofaciens.<\/p>\n<h3>Content<\/h3>\n<p>89.5 per cent to 102.0 per cent (anhydrous substance).<\/p>\n<h2>CHARACTERS<\/h2>\n<h3>Appearance<\/h3>\n<p>Yellow powder.<\/p>\n<h3>Solubility<\/h3>\n<p>Soluble or sparingly soluble in water, slightly soluble in ethanol (96 per cent), very slightly soluble in acetone. It dissolves in solutions of alkali hydroxides and carbonates.<\/p>\n<h2>IDENTIFICATION<\/h2>\n<p>A. Thin-layer chromatography (2.2.27).<\/p>\n<p>Test solution: Dissolve 5 mg of the substance to be examined in methanol R and dilute to 10 mL with the same solvent.<\/p>\n<p>Reference solution (a): Dissolve 5 mg of demeclocycline hydrochloride CRS in methanol R and dilute to 10 mL with the same solvent.<\/p>\n<p>Reference solution (b): Dissolve 5 mg of demeclocycline hydrochloride CRS, 5 mg of chlortetracycline hydrochloride R and 5 mg of tetracycline hydrochloride R in methanol R and dilute to 10 mL with the same solvent.<\/p>\n<p>Plate: TLC octadecylsilyl silica gel F254 plate R.<\/p>\n<p>Mobile phase: Mix 20 volumes of acetonitrile R, 20 volumes of methanol R and 60 volumes of a 63 g\/L solution of oxalic acid R previously adjusted to pH 2 with concentrated ammonia R.<\/p>\n<p>Application: 1 \u03bcL.<\/p>\n<p>Development: Over 3\/4 of the plate.<\/p>\n<p>Drying: In air.<\/p>\n<p>Detection: Examine in ultraviolet light at 254 nm.<\/p>\n<p>System suitability: The chromatogram obtained with reference solution (b) shows 3 clearly separated spots.<\/p>\n<p>Results: The principal spot in the chromatogram obtained with the test solution is similar in position and size to the principal spot in the chromatogram obtained with reference solution (a).<\/p>\n<p>B. To about 2 mg add 5 mL of sulfuric acid R. A violet colour develops. Add the solution to 2.5 mL of water R. The colour becomes yellow.<\/p>\n<p>C. It gives reaction (a) of chlorides (2.3.1).<\/p>\n<h2>TESTS<\/h2>\n<h3>pH (2.2.3)<\/h3>\n<p>2.0 to 3.0.<\/p>\n<p>Dissolve 0.1 g in carbon dioxide-free water R and dilute to 10 mL with the same solvent.<\/p>\n<h3>Related substances<\/h3>\n<p>Liquid chromatography (2.2.29). Prepare the solutions immediately before use.<\/p>\n<p>Buffer 1 22.2 g\/L solution of sodium edetate R adjusted to pH 7.5 with a 40 g\/L solution of sodium hydroxide R.<\/p>\n<p>Buffer 2 17.0 g\/L solution of tetrapropylammonium hydrogen sulfate R adjusted to pH 7.5 with a 40 g\/L solution of sodium hydroxide R.<\/p>\n<p>Test solution: Dissolve 25.0 mg of the substance to be examined in a 1.0 g\/L solution of hydrochloric acid R and dilute to 50.0 mL with the same solution.<\/p>\n<p>Reference solution (a): Dissolve 25.0 mg of demeclocycline hydrochloride CRS in a 1.0 g\/L solution of hydrochloric acid R and dilute to 50.0 mL with the same solution.<\/p>\n<p>Reference solution (b): Dilute 1.0 mL of the test solution to 100.0 mL with a 1.0 g\/L solution of hydrochloric acid R.<\/p>\n<p>Reference solution (c): Dissolve 5 mg of demeclocycline for system suitability CRS (containing impurities A, B, C, E and G) in a 1.0 g\/L solution of hydrochloric acid R and dilute to 10 mL with the same solution.<\/p>\n<p>Column:<\/p>\n<p>\u2014 size: l = 0.075 m, \u00d8 = 4.6 mm;<\/p>\n<p>\u2014 stationary phase: end-capped octylsilyl silica gel for chromatography with embedded polar groups R (3.5 \u03bcm);<\/p>\n<p>\u2014 temperature: 40 \u00b0C.<\/p>\n<p>Mobile phase:<\/p>\n<p>\u2014 mobile phase A: acetonitrile R, water for chromatography R, buffer 1, buffer 2 (2:28:35:35 V\/V\/V\/V);<\/p>\n<p>\u2014 mobile phase B: acetonitrile R, buffer 1, buffer 2 (30:35:35 V\/V\/V);<\/p>\n<table style=\"border-collapse: collapse; width: 100%; height: 106px;\">\n<tbody>\n<tr style=\"height: 43px;\">\n<td style=\"width: 33.3333%; height: 43px; text-align: center;\"><strong>Time<\/strong><\/p>\n<p><strong>(min)<\/strong><\/td>\n<td style=\"width: 33.3333%; height: 43px; text-align: center;\"><strong>Mobile phase A<\/strong><\/p>\n<p><strong>(per cent V\/V)<\/strong><\/td>\n<td style=\"width: 33.3333%; height: 43px; text-align: center;\"><strong>Mobile phase B<\/strong><\/p>\n<p><strong>(per cent V\/V)<\/strong><\/td>\n<\/tr>\n<tr style=\"height: 21px;\">\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">0 &#8211; 5<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">83<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">17<\/td>\n<\/tr>\n<tr style=\"height: 21px;\">\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">5 &#8211; 15<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">83 \u2192 30<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">17 \u2192 70<\/td>\n<\/tr>\n<tr style=\"height: 21px;\">\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">15 &#8211; 25<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">30<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">70<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Flow rate: 1 mL\/min.<\/p>\n<p>Detection: Spectrophotometer at 280 nm.<\/p>\n<p>Injection: 10 \u03bcL of the test solution and reference solutions (b) and (c).<\/p>\n<p>Identification of impurities: Use the chromatogram supplied with demeclocycline for system suitability CRS and the chromatogram obtained with reference solution (c) to identify the peaks due to impurities A, B, C, E and G.<\/p>\n<p>Relative retention: With reference to demeclocycline (retention time = about 14 min): impurity C = about 0.3; impurity B = about 0.7; impurity A = about 0.8; impurity E = about 1.2; impurity G = about 1.6.<\/p>\n<p>System suitability: Reference solution (c):<\/p>\n<p>\u2014 resolution: minimum 2.5 between the peaks due to impurities A and B.<\/p>\n<p>Calculation of percentage contents:<\/p>\n<p>\u2014 for each impurity, use the concentration of demeclocycline hydrochloride in reference solution (b).<\/p>\n<p>Limits:<\/p>\n<p>\u2014 impurities A, B: for each impurity, maximum 5.0 per cent;<\/p>\n<p>\u2014 impurities C, G: for each impurity, maximum 0.3 per cent;<\/p>\n<p>\u2014 impurity E: maximum 0.2 per cent;<\/p>\n<p>\u2014 any other impurity: for each impurity, maximum 0.15 per cent;<\/p>\n<p>\u2014 total: maximum 10.0 per cent;<\/p>\n<p>\u2014 reporting threshold: 0.05 per cent.<\/p>\n<h3>Water (2.5.12)<\/h3>\n<p>Maximum 3.0 per cent, determined on 1.000 g.<\/p>\n<h3>Sulfated ash (2.4.14)<\/h3>\n<p>Maximum 0.5 per cent, determined on 1.0 g.<\/p>\n<h2>ASSAY<\/h2>\n<p>Liquid chromatography (2.2.29) as described in the test for related substances with the following modification.<\/p>\n<p>Injection: 10 \u03bcL of the test solution and reference solution (a).<\/p>\n<p>Calculate the percentage content of C<sub>21<\/sub>H<sub>22<\/sub>Cl<sub>2<\/sub>N<sub>2<\/sub>O<sub>8<\/sub> using the chromatogram obtained with reference solution (a) and taking into account the assigned content of demeclocycline hydrochloride CRS.<\/p>\n<h2>STORAGE<\/h2>\n<p>Protected from light.<\/p>\n<h2>IMPURITIES<\/h2>\n<p>Specified impurities A, B, C, E, G.<\/p>\n<p>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) D, F.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-11854\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/2-102-300x163.jpg\" alt=\"Demeclocycline Hydrochloride\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/2-102-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/2-102-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/2-102-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/2-102.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>A. (4S,4aS,5aS,6S,12aS)-4-(dimethylamino)-3,6,10,12,12a-pentahydroxy-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide (demethyltetracycline),<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-11855\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/3-96-300x163.jpg\" alt=\"Demeclocycline Hydrochloride\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/3-96-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/3-96-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/3-96-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/3-96.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>B. (4R,4aS,5aS,6S,12aS)-7-chloro-4-(dimethylamino)-3,6,10,12,12a-pentahydroxy-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide (4-epidemeclocycline),<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-11856\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/4-88-300x163.jpg\" alt=\"Demeclocycline Hydrochloride\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/4-88-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/4-88-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/4-88-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/4-88.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>C. (4R,4aS,5aS,6S,12aS)-4-(dimethylamino)-3,6,10,12,12a-pentahydroxy-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide (4-epidemethyltetracycline),<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-11857\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/5-68-300x163.jpg\" alt=\"Demeclocycline Hydrochloride\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/5-68-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/5-68-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/5-68-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/5-68.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>D. (4R,4aS,12aS)-4-(dimethylamino)-3,10,11,12a-tetrahydroxy-1,12-dioxo-1,4,4a,5,12,12a-hexahydrotetracene-2-carboxamide (4-epianhydrodemethyltetracycline),<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-11858\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/6-58-300x163.jpg\" alt=\"Demeclocycline Hydrochloride\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/6-58-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/6-58-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/6-58-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/6-58.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>E. (4S,4aS,12aS)-4-(dimethylamino)-3,10,11,12a-tetrahydroxy-1,12-dioxo-1,4,4a,5,12,12a-hexahydrotetracene-2-carboxamide (anhydrodemethyltetracycline),<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-11859\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/7-50-300x163.jpg\" alt=\"Demeclocycline Hydrochloride\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/7-50-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/7-50-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/7-50-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/7-50.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>F. (4R,4aS,12aS)-7-chloro-4-(dimethylamino)-3,10,11,12a-tetrahydroxy-1,12-dioxo-1,4,4a,5,12,12a-hexahydrotetracene-2-carboxamide (4-epianhydrodemeclocycline),<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-11860\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/8-36-300x163.jpg\" alt=\"Demeclocycline Hydrochloride\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/8-36-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/8-36-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/8-36-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/8-36.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>G. (4S,4aS,12aS)-7-chloro-4-(dimethylamino)-3,10,11,12a-tetrahydroxy-1,12-dioxo-1,4,4a,5,12,12a-hexahydrotetracene-2-carboxamide (anhydrodemeclocycline).<\/p>\n","protected":false},"excerpt":{"rendered":"<p>(Ph. Eur. monograph 0176) C21H22Cl2N2O8 501.3 64-73-3 Action and use Tetracycline antibacterial. Preparation Demeclocycline Capsules DEFINITION (4S,4aS,5aS,6S,12aS)-7-Chloro-4-(dimethylamino)-3,6,10,12,12a-pentahydroxy-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide hydrochloride. Substance produced by certain strains of Streptomyces aureofaciens. Content 89.5 per cent to 102.0 per cent (anhydrous substance). CHARACTERS Appearance Yellow powder. Solubility Soluble or sparingly soluble in water, slightly soluble in ethanol (96 per cent), very&#8230;<\/p>\n","protected":false},"author":4,"featured_media":11853,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-11825","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\/11825","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=11825"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/11825\/revisions"}],"predecessor-version":[{"id":11878,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/11825\/revisions\/11878"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/11853"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=11825"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=11825"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=11825"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}