{"id":25581,"date":"2025-11-04T15:50:55","date_gmt":"2025-11-04T08:50:55","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=25581"},"modified":"2025-11-04T15:50:55","modified_gmt":"2025-11-04T08:50:55","slug":"nitrendipine","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/nitrendipine\/","title":{"rendered":"Nitrendipine"},"content":{"rendered":"

(Ph. Eur. monograph 1246)<\/p>\n

C18<\/sub>H20<\/sub>N2<\/sub>O6<\/sub>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 360.4\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a039562-70-4<\/p>\n

Action and use<\/strong><\/p>\n

Calcium channel blocker.<\/p>\n

DEFINITION<\/h2>\n

Ethyl methyl (4RS)-2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate.<\/p>\n

Content<\/h3>\n

98.5 per cent to 101.5 per cent (dried substance).<\/p>\n

CHARACTERS<\/h2>\n

Appearance<\/h3>\n

Yellow, crystalline powder.<\/p>\n

Solubility<\/h3>\n

Practically insoluble in water, freely soluble in ethyl acetate, sparingly soluble in anhydrous ethanol and in methanol.<\/p>\n

It shows polymorphism (5.9).<\/p>\n

Exposure to ultraviolet light leads to the formation of a nitrophenylpyridine derivative.<\/p>\n

Prepare solutions immediately before use either protected from light or under long-wavelength light (> 420 nm).<\/p>\n

IDENTIFICATION<\/h2>\n

Infrared absorption spectrophotometry (2.2.24).<\/p>\n

Comparison :nitrendipine CRS.<\/p>\n

If the spectra obtained in the solid state show differences, record new spectra using 20 g\/L solutions in methylene chloride R and a 0.2 mm cell.<\/p>\n

TESTS<\/h2>\n

Related substances<\/h3>\n

Liquid chromatography (2.2.29).<\/p>\n

Test solution: Dissolve 20 mg of the substance to be examined in 2.5 mL of tetrahydrofuran R and dilute to 10.0 mL with the mobile phase.<\/p>\n

Reference solution (a): Dilute 1.0 mL of the test solution to 100.0 mL with the mobile phase. Dilute 1.0 mL of this solution to 10.0 mL with the mobile phase.<\/p>\n

Reference solution (b): Dissolve 15.0 mg of nitrendipine impurity A CRS in 2.5 mL of tetrahydrofuran R and dilute to 10.0 mL with the mobile phase. Dilute 1.0 mL of this solution to 20.0 mL with the mobile phase.<\/p>\n

Reference solution (c): Dilute 0.5 mL of the test solution to 20.0 mL with the mobile phase.<\/p>\n

Reference solution (d): Mix 1.0 mL of reference solution (b) and 1.0 mL of reference solution (c), then dilute to 25.0 mL with the mobile phase.<\/p>\n

Reference solution (e): Dissolve 2 mg of nitrendipine for peak identification CRS (containing impurities B and C) in 0.5 mL of tetrahydrofuran R and dilute to 1.0 mL with the mobile phase.<\/p>\n

Column:<\/p>\n

\u2014 size: l = 0.125 m, \u00d8 = 4 mm;<\/p>\n

\u2014 stationary phase: irregular octadecylsilyl silica gel for chromatography R (5 \u03bcm);<\/p>\n

\u2014 temperature: 40 \u00b0C.<\/p>\n

Mobile phase: acetonitrile R, tetrahydrofuran R, water R (14:22:64 V\/V\/V).<\/p>\n

Flow rate: 1 mL\/min.<\/p>\n

Detection: Spectrophotometer at 235 nm.<\/p>\n

Injection: 10 \u03bcL of the test solution and reference solutions (a), (d) and (e).<\/p>\n

Run time: 5 times the retention time of nitrendipine.<\/p>\n

Identification of impurities: Use the chromatogram supplied with nitrendipine for peak identification CRS and the chromatogram obtained with reference solution (e) to identify the peaks due to impurities B and C; use the chromatogram obtained with reference solution (d) to identify the peak due to impurity A.<\/p>\n

Relative retention: With reference to nitrendipine (retention time = about 9 min): impurity B = about 0.7; impurity A = about 0.8; impurity C = about 1.4.<\/p>\n

System suitability: Reference solution (d):<\/p>\n

\u2014 resolution: minimum 2.0 between the peaks due to impurity A and nitrendipine.<\/p>\n

Limits:<\/p>\n

\u2014 impurities B, C: for each impurity, not more than 4 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.4 per cent);<\/p>\n

\u2014 impurity A: not more than the area of the corresponding peak in the chromatogram obtained with reference solution (d) (0.15 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 (a) (0.10 per cent);<\/p>\n

\u2014 total: maximum 0.7 per cent;<\/p>\n

\u2014 disregard limit: 0.5 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.05 per cent).<\/p>\n

Loss on drying (2.2.32)<\/h4>\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)<\/h4>\n

Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n

ASSAY<\/h2>\n

Dissolve 0.160 g with gentle heating if necessary 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. Titrate slowly towards the end of the titration. Carry out a blank titration.<\/p>\n

1 mL of 0.1 M cerium sulfate is equivalent to 18.02 mg of C18<\/sub>H20<\/sub>N2<\/sub>O6<\/sub>.<\/p>\n

STORAGE<\/h2>\n

Protected from light.<\/p>\n

IMPURITIES<\/h2>\n

Specified impurities A, B, C.<\/p>\n

\"Nitrendipine\"<\/p>\n

A. ethyl methyl 2,6-dimethyl-4-(3-nitrophenyl)pyridine-3,5-dicarboxylate,<\/p>\n

\"Nitrendipine\"<\/p>\n

B. dimethyl 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate,<\/p>\n

\"Nitrendipine\"<\/p>\n

C. diethyl 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate.<\/p>\n","protected":false},"excerpt":{"rendered":"

(Ph. Eur. monograph 1246) C18H20N2O6\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 360.4\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a039562-70-4 Action and use Calcium channel blocker. DEFINITION Ethyl methyl (4RS)-2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate. Content 98.5 per cent to 101.5 per cent (dried substance). CHARACTERS Appearance Yellow, crystalline powder. Solubility Practically insoluble in water, freely soluble in ethyl…<\/p>\n","protected":false},"author":2,"featured_media":25599,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-25581","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\/25581","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=25581"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/25581\/revisions"}],"predecessor-version":[{"id":25601,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/25581\/revisions\/25601"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/25599"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=25581"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=25581"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=25581"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}