Edition: BP 2025 (Ph. Eur. 11.6 update)<\/p>\n
Action and use<\/strong><\/p>\n Cyclo-oxygenase inhibitor; analgesic; anti-inflammatory.<\/p>\n Preparations<\/strong><\/p>\n Naproxen Oral Suspension Naproxen Tablets<\/p>\n Naproxen Gastro-resistant Tablets Ph Eur<\/p>\n (2S)-2-(6-Methoxynaphthalen-2-yl)propanoic acid.<\/p>\n Content<\/strong><\/p>\n 99.0 per cent to 101.0 per cent (dried substance).<\/p>\n White or almost white, crystalline powder.<\/p>\n Practically insoluble in water, soluble in ethanol (96 per cent) and in methanol.<\/p>\n First identification: A, D. <\/em><\/p>\n Second identification: A, B, C.<\/em><\/p>\n A. Specific optical rotation (2.2.7): + 59 to + 62 (dried substance).<\/p>\n Dissolve 0.50 g in ethanol (96 per cent) R and dilute to 25.0 mL with the same solvent.<\/p>\n B. Melting point (2.2.14): 154 \u00b0C to 158 \u00b0C.<\/p>\n C. Ultraviolet and visible absorption spectrophotometry (2.2.25).<\/p>\n Test solution\u00a0 Dissolve 40.0 mg in methanol R and dilute to 100.0 mL with the same solvent. Dilute 10.0 mL of the solution to 100.0 mL with methanol R.<\/p>\n Spectral range\u00a0 230-350 nm.<\/p>\n Absorption maxima\u00a0 At 262 nm, 271 nm, 316 nm and 331 nm.<\/p>\n Specific absorbances at the absorption maxima:<\/p>\n \u2014 at 262 nm: 216 to 238;<\/p>\n \u2014 at 271 nm: 219 to 241;<\/p>\n \u2014 at 316 nm: 61 to 69;<\/p>\n \u2014 at 331 nm: 79 to 87.<\/p>\n D. Infrared absorption spectrophotometry (2.2.24).<\/p>\n Comparison\u00a0 naproxen CRS.<\/em><\/p>\n The solution is clear (2.2.1) and not more intensely coloured than reference solution BY7 (2.2.2, Method II). Dissolve 1.25 g in methanol R and dilute to 25 mL with the same solvent.<\/p>\n Liquid chromatography (2.2.29). Protect the solutions from light.<\/p>\n Test solution\u00a0 Dissolve 25.0 mg of the substance to be examined in tetrahydrofuran R and dilute to 50.0 mL with the same solvent. Dilute 2.0 mL of the solution to 20.0 mL with the mobile phase.<\/p>\n Reference solution (a)\u00a0 Dilute 2.5 mL of the test solution to 100.0 mL with the mobile phase.<\/p>\n Reference solution (b)\u00a0 Dissolve 5 mg of racemic naproxen CRS in 10.0 mL of tetrahydrofuran R and dilute to 100.0 mL with the mobile phase.<\/p>\n Column:<\/p>\n \u2014 size: l = 0.25 m, \u00d8 = 4.6 mm;<\/p>\n \u2014 stationary phase: silica gel \u03c0-acceptor\/\u03c0-donor for chiral separations R (5 \u00b5m) (S,S);<\/p>\n \u2014 temperature: 25 \u00b0C.<\/p>\n Mobile phase\u00a0 glacial acetic acid R, acetonitrile R, 2-propanol R, hexane R (0.5:5:10:84.5 V\/V\/V\/V). Flow rate 2 mL\/min.<\/p>\n Detection\u00a0 Spectrophotometer at 263 nm.<\/p>\n Injection\u00a0 20 \u00b5L.<\/p>\n Run time\u00a0 1.5 times the retention time of naproxen (retention time = about 5 min).<\/p>\n System suitability\u00a0 Reference solution (b):<\/p>\n \u2014 resolution: minimum 3 between the peaks due to impurity G and naproxen.<\/p>\n Limit:<\/p>\n \u2014 impurity G: not more than the area of the principal peak in the chromatogram obtained with reference solution (a) (2.5 per cent).<\/p>\n Liquid chromatography (2.2.29). Protect the solutions from light.<\/p>\n Test solution\u00a0 Dissolve 12 mg of the substance to be examined in the mobile phase and dilute to 20 mL with the mobile phase.<\/p>\n Reference solution (a)\u00a0 Dilute 1.0 mL of the test solution to 50.0 mL with the mobile phase. Dilute 1.0 mL of this solution to 20.0 mL with the mobile phase.<\/p>\n Reference solution (b)\u00a0 Dissolve 6 mg of bromomethoxynaphthalene R (impurity N), 6.0 mg of naproxen impurity L CRS, 6 mg of 6-methoxy-2-naphthoic acid R (impurity O) and 6 mg of\u00a0 (1RS)-1-(6-methoxynaphthalen-2-yl)ethanol R (impurity K) in acetonitrile R and dilute to 10.0 mL with the same solvent. To 1.0 mL of the solution add 1.0 mL of the test solution and dilute to 50.0 mL with the mobile phase. Dilute 1.0 mL of this solution to 20.0 mL with the mobile phase.<\/p>\n Column:<\/p>\n \u2014 size: l = 0.10 m, \u00d8 = 4.0 mm;<\/p>\n \u2014 stationary phase: end-capped octadecylsilyl silica gel for chromatography R (3 \u00b5m);<\/p>\n \u2014 temperature: 50 \u00b0C.<\/p>\n Mobile phase\u00a0 Mix 42 volumes of acetonitrile R and 58 volumes of a 1.36 g\/L solution of potassium dihydrogen phosphate R previously adjusted to pH 2.0 with phosphoric acid R.<\/p>\n Flow rate\u00a0 1.5 mL\/min.<\/p>\n Detection\u00a0 Spectrophotometer at 230 nm.<\/p>\n Injection\u00a0 20 \u00b5L.<\/p>\n Run time\u00a0 1.5 times the retention time of impurity N.<\/p>\n Identification of impurities\u00a0 Use the chromatogram obtained with reference solution (b) to identify the peaks due to impurities K, L, N and O.<\/p>\n Relative retention\u00a0 With reference to naproxen (retention time = about 2.5 min): impurity O = about 0.8; impurity K = about 0.9; impurity L = about 1.4; impurity N = about 5.3.<\/p>\n System suitability\u00a0 Reference solution (b):<\/p>\n \u2014 resolution: minimum 2.2 between the peaks due to impurity K and naproxen.<\/p>\n Limits:<\/p>\n \u2014 correction factor: for the calculation of content, multiply the peak area of impurity O by 2.0;<\/p>\n \u2014 impurity O: not more than 1.5 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.15 per cent);<\/p>\n \u2014 impurity L: not more than 1.5 times the area of the corresponding peak in the chromatogram obtained with reference solution (b) (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: not more than 3 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.3 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)<\/strong><\/p>\n Maximum 0.5 per cent, determined on 1.000 g by drying in an oven at 105 \u00b0C for 3 h.<\/p>\n Sulfated ash (2.4.14)<\/strong><\/p>\n Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n Dissolve 0.200 g in a mixture of 25 mL of water R and 75 mL of methanol R. Titrate with 0.1 M sodium hydroxide, using 1 mL of phenolphthalein solution R as indicator.<\/p>\n 1 mL of 0.1 M sodium hydroxide is equivalent to 23.03 mg of C14H14O3.<\/p>\n Protected from light.<\/p>\n Specified impurities\u00a0 G, L, O.<\/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.<\/em><\/p>\n Control of impurities in substances for pharmaceutical use)\u00a0 A, B, C, D, E, F, H, I, J, K, M, N.<\/em><\/p>\n A. (2S)-2-(6-hydroxynaphthalen-2-yl)propanoic acid,<\/p>\n B. (2S)-2-(5-chloro-6-methoxynaphthalen-2-yl)propanoic acid,<\/p>\n C. (2S)-2-(5-bromo-6-methoxynaphthalen-2-yl)propanoic acid,<\/p>\n D. (2S)-2-(5-iodo-6-methoxynaphthalen-2-yl)propanoic acid,<\/p>\n E. methyl (2S)-2-(6-methoxynaphthalen-2-yl)propanoate,<\/p>\n F. ethyl (2S)-2-(6-methoxynaphthalen-2-yl)propanoate,<\/p>\n G. (2R)-2-(6-methoxynaphthalen-2-yl)propanoic acid ((R)-enantiomer),<\/p>\n H. 6-methoxynaphthalen-2-ol,<\/p>\n I. (6-methoxynaphthalen-2-yl)acetic acid,<\/p>\n J. 2-ethyl-6-methoxynaphthalene,<\/p>\n K. (1RS)-1-(6-methoxynaphthalen-2-yl)ethanol,<\/p>\n L. 1-(6-methoxynaphthalen-2-yl)ethanone,<\/p>\n M. 2-methoxynaphthalene (nerolin),<\/p>\n N. 2-bromo-6-methoxynaphthalene,<\/p>\n O. 6-methoxynaphthalene-2-carboxylic acid (6-methoxy-2-naphthoic acid).<\/p>\n Ph Eur<\/p>\n","protected":false},"excerpt":{"rendered":" Edition: BP 2025 (Ph. Eur. 11.6 update) Action and use Cyclo-oxygenase inhibitor; analgesic; anti-inflammatory. Preparations Naproxen Oral Suspension Naproxen Tablets Naproxen Gastro-resistant Tablets Ph Eur DEFINITION (2S)-2-(6-Methoxynaphthalen-2-yl)propanoic acid. Content 99.0 per cent to 101.0 per cent (dried substance). CHARACTERS Appearance White or almost white, crystalline powder. Solubility Practically insoluble in water, soluble in ethanol (96…<\/p>\n","protected":false},"author":5,"featured_media":25761,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-25760","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\/25760","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=25760"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/25760\/revisions"}],"predecessor-version":[{"id":25767,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/25760\/revisions\/25767"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/25761"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=25760"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=25760"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=25760"}],"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
Appearance of solution<\/h3>\n
Enantiomeric purity<\/h3>\n
Related substances<\/h3>\n
ASSAY<\/h2>\n
STORAGE<\/h2>\n
IMPURITIES<\/h2>\n
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