﻿{"id":25327,"date":"2025-11-04T11:43:04","date_gmt":"2025-11-04T04:43:04","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=25327"},"modified":"2025-11-04T11:43:04","modified_gmt":"2025-11-04T04:43:04","slug":"nifedipine","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/nifedipine\/","title":{"rendered":"Nifedipine"},"content":{"rendered":"<p>(Ph. Eur. monograph 0627)<\/p>\n<p>C<sub>17<\/sub>H<sub>18<\/sub>N<sub>2<\/sub>O<sub>6\u00a0<\/sub> \u00a0 \u00a0 \u00a0 \u00a0346.3\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a021829-25-4<\/p>\n<p><strong>Action and use<\/strong><\/p>\n<p>Calcium channel blocker.<\/p>\n<p><strong>Preparations<\/strong><\/p>\n<p>Nifedipine Capsules<\/p>\n<p>Nifedipine Oral Suspension<\/p>\n<p>Nifedipine Prolonged-release Capsules<\/p>\n<p>Nifedipine Prolonged-release Capsules<\/p>\n<p>Nifedipine Prolonged-release Tablets<\/p>\n<h2>DEFINITION<\/h2>\n<p>Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate.<\/p>\n<h3>Content<\/h3>\n<p>98.0 per cent to 102.0 per cent (dried substance).<\/p>\n<h2>CHARACTERS<\/h2>\n<h3>Appearance<\/h3>\n<p>Yellow, crystalline powder.<\/p>\n<h3>Solubility<\/h3>\n<p>Practically insoluble in water, freely soluble in acetone, sparingly soluble in anhydrous ethanol.<\/p>\n<p>When exposed to daylight and to artificial light of certain wavelengths, it readily converts to a nitrosophenylpyridine derivative. Exposure to ultraviolet light leads to the formation of a nitrophenylpyridine derivative.<\/p>\n<p>Prepare solutions immediately before use in the dark or under long-wavelength light (&gt; 420 nm) and protect them from light.<\/p>\n<h2>IDENTIFICATION<\/h2>\n<p>First identification: B.<\/p>\n<p>Second identification: A, C, D.<\/p>\n<p>A. Melting point (2.2.14): 171 \u00b0C to 175 \u00b0C.<\/p>\n<p>B. Infrared absorption spectrophotometry (2.2.24).<\/p>\n<p>Comparison: nifedipine CRS.<\/p>\n<p>C. Thin-layer chromatography (2.2.27).<\/p>\n<p>Test solution: Dissolve 10 mg of the substance to be examined in methanol R and dilute to 10 mL with the same solvent.<\/p>\n<p>Reference solution: Dissolve 10 mg of nifedipine CRS in methanol R and dilute to 10 mL with the same solvent.<\/p>\n<p>Plate: TLC silica gel F254 plate R.<\/p>\n<p>Mobile phase: ethyl acetate R, cyclohexane R (40:60 V\/V).<\/p>\n<p>Application: 5 \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>Results: The principal spot in the chromatogram obtained with the test solution is similar in position, appearance at 254 nm and size to the principal spot in the chromatogram obtained with the reference solution.<\/p>\n<p>D. To 25 mg in a test tube, add 10 mL of a mixture of 1.5 volumes of hydrochloric acid R, 3.5 volumes of water R and 5 volumes of alcohol R and dissolve with gentle heating. Add 0.5 g of zinc R in granules and allow to stand for 5 min with occasional swirling. Filter into a second test tube, add 5 mL of a 10 g\/L solution of sodium nitrite R to the filtrate and allow to stand for 2 min. Add 2 mL of a 50 g\/L solution of ammonium sulfamate R, shake vigorously with care and add 2 mL of a 5 g\/L solution of naphthylethylenediamine dihydrochloride R. An intense red colour develops which persists for not less than 5 min.<\/p>\n<h2>TESTS<\/h2>\n<h3>Impurity D and other basic impurities<\/h3>\n<p>Transfer 4 g to a 250 mL conical flask and dissolve in 160 mL of glacial acetic acid R using an ultrasonic bath. Titrate with 0.1 M perchloric acid using 0.25 mL of naphtholbenzein solution R as indicator until the colour changes from brownish-yellow to green. Not more than 0.48 mL of 0.1 M perchloric acid is required<br \/>\n(0.14 per cent).<\/p>\n<h3>Related substances<\/h3>\n<p>Liquid chromatography (2.2.29).<\/p>\n<p>Test solution: Dissolve 0.200 g of the substance to be examined in 20 mL of methanol R and dilute to 50.0 mL with the mobile phase.<\/p>\n<p>Reference solution (a): Dissolve 10 mg of nifedipine impurity A CRS in methanol R and dilute to 25.0 mL with the same solvent.<\/p>\n<p>Reference solution (b): Dissolve 10 mg of nifedipine impurity B CRS in methanol R and dilute to 25.0 mL with the same solvent.<\/p>\n<p>Reference solution (c): Mix 1.0 mL of reference solution (a), 1.0 mL of reference solution (b) and 0.1 mL of the test solution and dilute to 20.0 mL with the mobile phase. Dilute 2.0 mL of this solution to 10.0 mL with the mobile phase.<\/p>\n<p>Column:<\/p>\n<p>\u2014 size: l = 0.15 m, \u00d8 = 4.6 mm,<\/p>\n<p>\u2014 stationary phase: octadecylsilyl silica gel for chromatography R (5 \u03bcm).<\/p>\n<p>Mobile phase: acetonitrile R, methanol R, water R (9:36:55 V\/V\/V).<\/p>\n<p>Flow rate: 1.0 mL\/min.<\/p>\n<p>Detection: Spectrophotometer at 235 nm.<\/p>\n<p>Injection: 20 \u03bcL; inject the test solution and reference solution (c).<\/p>\n<p>Run time: Twice the retention time of nifedipine.<\/p>\n<p>Elution order: Impurity A, impurity B, nifedipine.<\/p>\n<p>Retention time: Nifedipine = about 15.5 min.<\/p>\n<p>System suitability: Reference solution (c):<\/p>\n<p>\u2014 resolution: minimum 1.5 between the peaks due to impurity A and impurity B and minimum 1.5 between the peaks due to impurity B and nifedipine.<\/p>\n<p>Limits:<\/p>\n<p>\u2014 impurity A: not more than the area of the corresponding peak in the chromatogram obtained with reference solution (c) (0.1 per cent),<\/p>\n<p>\u2014 impurity B: not more than the area of the corresponding peak in the chromatogram obtained with reference solution (c) (0.1 per cent),<\/p>\n<p>\u2014 any other impurity: not more than the area of the peak due to nifedipine in the chromatogram obtained with reference solution (c) (0.1 per cent),<\/p>\n<p>\u2014 total: not more than 0.3 per cent,<\/p>\n<p>\u2014 disregard limit: 0.1 times the area of the peak due to nifedipine in the chromatogram obtained with reference solution (c) (0.01 per cent).<\/p>\n<h4>Loss on drying (2.2.32)<\/h4>\n<p>Maximum 0.5 per cent, determined on 1.000 g by drying in an oven at 105 \u00b0C for 2 h.<\/p>\n<h4>Sulfated ash (2.4.14)<\/h4>\n<p>Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n<h2>ASSAY<\/h2>\n<p>Dissolve 0.1300 g in a mixture of 25 mL of 2-methyl-2-propanol R and 25 mL of perchloric acid solution R. Titrate with 0.1 M cerium sulfate using 0.1 mL of ferroin R as indicator, until the pink colour disappears. Titrate slowly towards the end of the titration. Carry out a blank titration.<\/p>\n<p>1 mL of 0.1 M cerium sulfate is equivalent to 17.32 mg of C<sub>17<\/sub>H<sub>18<\/sub>N<sub>2<\/sub>O<sub>6<\/sub>.<\/p>\n<h2>STORAGE<\/h2>\n<p>Protected from light.<\/p>\n<h2>IMPURITIES<\/h2>\n<p>Specified impurities A, B, C, D.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-25329\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-2-300x163.jpg\" alt=\"Nifedipine\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-2-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-2-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-2-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-2.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>A. dimethyl 2,6-dimethyl-4-(2-nitrophenyl)pyridine-3,5-dicarboxylate (nitrophenylpyridine analogue),<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-25330\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-3-300x163.jpg\" alt=\"Nifedipine\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-3-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-3-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-3-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-3.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>B. dimethyl 2,6-dimethyl-4-(2-nitrosophenyl)pyridine-3,5-dicarboxylate (nitrosophenylpyridine analogue),<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-25331\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-4-300x163.jpg\" alt=\"Nifedipine\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-4-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-4-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-4-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-4.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>C. methyl 2-(2-nitrobenzylidene)-3-oxobutanoate,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-25332\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-5-300x163.jpg\" alt=\"Nifedipine\" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-5-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-5-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-5-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Nifedipine-5.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>D. methyl 3-aminobut-2-enoate.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>(Ph. Eur. monograph 0627) C17H18N2O6\u00a0 \u00a0 \u00a0 \u00a0 \u00a0346.3\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a021829-25-4 Action and use Calcium channel blocker. Preparations Nifedipine Capsules Nifedipine Oral Suspension Nifedipine Prolonged-release Capsules Nifedipine Prolonged-release Capsules Nifedipine Prolonged-release Tablets DEFINITION Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate. Content 98.0 per cent to 102.0 per cent (dried substance). CHARACTERS Appearance Yellow, crystalline powder. Solubility&#8230;<\/p>\n","protected":false},"author":2,"featured_media":25333,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-25327","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\/25327","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\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=25327"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/25327\/revisions"}],"predecessor-version":[{"id":25335,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/25327\/revisions\/25335"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/25333"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=25327"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=25327"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=25327"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}