{"id":28864,"date":"2025-11-10T08:22:10","date_gmt":"2025-11-10T01:22:10","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=28864"},"modified":"2025-11-10T08:22:10","modified_gmt":"2025-11-10T01:22:10","slug":"tenoxicam","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/tenoxicam\/","title":{"rendered":"Tenoxicam"},"content":{"rendered":"

Edition: BP 2025 (Ph. Eur. 11.6 update)
\nGeneral Notices (Ph. Eur. monograph 1156)<\/p>\n

\"C13H11N3O4S2
C13H11N3O4S2 337.4 59804-37-4<\/figcaption><\/figure>\n

Action and use<\/strong>
\nCyclo-oxygenase inhibitor; analgesic; anti-inflammatory.<\/p>\n

Preparations
\nTenoxicam Injection
\nTenoxicam Tablets<\/p>\n

Ph Eur<\/p>\n

DEFINITION<\/h2>\n

4-Hydroxy-2-methyl-N-(pyridin-2-yl)-2H-thieno[2,3-e]1,2-thiazine-3-carboxamide 1,1-dioxide.<\/p>\n

Content: 99.0 per cent to 101.0 per cent (anhydrous substance).<\/p>\n

CHARACTERS<\/h2>\n

Appearance<\/h3>\n

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

Solubility<\/h3>\n

Practically insoluble in water, sparingly soluble in methylene chloride, very slightly soluble in anhydrous ethanol. It dissolves in solutions of acids and alkalis. It shows polymorphism (5.9).<\/p>\n

IDENTIFICATION<\/h2>\n

Infrared absorption spectrophotometry (2.2.24). Comparison: tenoxicam CRS.
\nIf the spectra obtained in the solid state show differences, dissolve the substance to be examined and the reference substance separately in the minimum volume of methylene chloride R, evaporate to dryness and record new spectra using the residues.<\/p>\n

TESTS<\/h2>\n

Appearance of solution<\/h3>\n

The solution is clear (2.2.1).<\/p>\n

Dissolve 0.10 g in methylene chloride R and dilute to 20 mL with the same solvent.<\/p>\n

Related substances<\/h3>\n

Liquid chromatography (2.2.29). Carry out the test protected from light.<\/p>\n

Solvent mixture: Mix equal volumes of acetonitrile R and water R. Adjust to apparent pH 3.2 with dilute phosphoric acid R1.<\/p>\n

Test solution: Dissolve 35 mg of the substance to be examined in the solvent mixture, sonicate and dilute to 50.0 mL with the solvent mixture.<\/p>\n

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

Reference solution (b): Dissolve 7 mg of pyridin-2-amine R (impurity A) in the solvent mixture and dilute to 100.0 mL with the solvent mixture. Dilute 1.0 mL of this solution to 100.0 mL with the solvent mixture.<\/p>\n

Reference solution (c): Dissolve the contents of a vial of tenoxicam impurity mixture CRS (impurities B, G and H) in 1.0 mL of the test solution.<\/p>\n

Column:
\n\u2014 size: l = 0.15 m, \u00d8 = 4.6 mm;
\n\u2014 stationary phase: diisopropylcyanosilyl silica gel for chromatography R (3.5 \u03bcm);
\n\u2014 temperature: 35 \u00b0C.<\/p>\n

Mobile phase:
\n\u2014 mobile phase A: mix 25 volumes of methanol R2 and 75 volumes of water for chromatography R and adjust to apparent pH 3.2 with dilute phosphoric acid R1;
\n\u2014 mobile phase B: mix 25 volumes of water for chromatography R and 75 volumes of methanol R2 and adjust to apparent pH 3.2 with dilute phosphoric acid R1.<\/p>\n\n\n\n\n\n\n
Time (min)<\/td>\nMobile phase A (% V\/V)<\/td>\nMobile phase B (% V\/V)<\/td>\n<\/tr>\n
0 – 5<\/td>\n96<\/td>\n4<\/td>\n<\/tr>\n
5-16<\/td>\n96 \u2192 76<\/td>\n4 \u2192 24<\/td>\n<\/tr>\n
16-25<\/td>\n76<\/td>\n24<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Flow rate 1.0 mL\/min.<\/p>\n

Detection: Spectrophotometer at 230 nm.
\nInjection: 20 \u03bcL.<\/p>\n

Identification of impurities:
\n\u2014 use the chromatogram obtained with reference solution (b) to identify the peak due to impurity A;
\n\u2014 use the chromatogram supplied with tenoxicam impurity mixture CRS and the chromatogram obtained with reference solution (c) to identify the peaks due to impurities B, G and H; for identification of impurities G and H, which may be inverted in the elution order, take into account the heights of the corresponding peaks in the chromatogram supplied with tenoxicam impurity mixture CRS.<\/p>\n

Relative retention: With reference to tenoxicam (retention time = about 12 min): impurity A = about 0.1; impurity G = about 0.85; impurity H = about 0.9; impurity B = about 1.3.<\/p>\n

System suitability (Reference solution c):
\n\u2014 resolution: minimum 1.3 between the peaks due to impurity H (or G if peaks are inverted) and tenoxicam, and between the peaks due to impurities G and H; if necessary, optimise the apparent pH of the mobile phases within the range 3.0\u20133.4.<\/p>\n

Limits:
\n\u2014 correction factors: impurity A = 0.2; impurity B = 2.0;
\n\u2014 impurities A, B: for each impurity, \u22641.5\u00d7 the area of the principal peak in reference solution (a) (0.15%);
\n\u2014 unspecified impurities: \u2264 the area of the principal peak in reference solution (a) (0.10%);
\n\u2014 total impurities: \u22643\u00d7 the area of the principal peak in reference solution (a) (0.3%);
\n\u2014 disregard limit: 0.5\u00d7 the area of the principal peak in reference solution (a) (0.05%).<\/p>\n

Water (2.5.12): Maximum 0.5% (determined on 1.000 g).
\nSulfated ash (2.4.14): Maximum 0.1% (determined on 1.0 g).<\/p>\n

ASSAY<\/h2>\n

Dissolve 0.250 g in 5 mL of anhydrous formic acid R. Add 70 mL of anhydrous acetic acid R. Titrate with 0.1 M perchloric acid, determining the end-point potentiometrically (2.2.20).
\n1 mL of 0.1 M perchloric acid \u2261 33.74 mg of C13H11N3O4S2.<\/p>\n

STORAGE<\/h2>\n

Protected from light.<\/p>\n

IMPURITIES<\/h2>\n

Specified impurities: A, B.
\nOther detectable impurities: C, D, E, F, G, H (these are limited by the general acceptance criterion for unspecified impurities and\/or by the general monograph Substances for pharmaceutical use (2034)). It is therefore not necessary to identify these impurities for compliance purposes.<\/p>\n

\"A.
A. pyridin-2-amine,<\/figcaption><\/figure>\n
\"B.
B. methyl 4-hydroxy-2-methyl-2H-thieno[2,3-e]1,2-thiazine-3-carboxylate 1,1-dioxide,<\/figcaption><\/figure>\n
\"C.
C. N-methylthiophene-2-carboxamide,<\/figcaption><\/figure>\n
\"D.
D. N-methyl-N\u2032-(pyridin-2-yl)-ethanediamide,<\/figcaption><\/figure>\n
\"E.
E. 2-methylthieno[2,3-d]isothiazol-3(2H)-one 1,1-dioxide,<\/figcaption><\/figure>
\"F.
F. 4-hydroxy-N,2-dimethyl-N-(pyridin-2-yl)-2H-thieno[2,3-e]1,2-thiazine-3-carboxamide 1,1-dioxide,<\/figcaption><\/figure>
\"G.
G. 4-hydroxy-2-methyl-2H-thieno[2,3-e]1,2-thiazine-3-carboxamide 1,1-dioxide,<\/figcaption><\/figure>
\"H.
H. 3-[(methylamino)sulfonyl]thiophene-2-carboxylic acid.<\/figcaption><\/figure>\n","protected":false},"excerpt":{"rendered":"

Edition: BP 2025 (Ph. Eur. 11.6 update) General Notices (Ph. Eur. monograph 1156) Action and use Cyclo-oxygenase inhibitor; analgesic; anti-inflammatory. Preparations Tenoxicam Injection Tenoxicam Tablets Ph Eur DEFINITION 4-Hydroxy-2-methyl-N-(pyridin-2-yl)-2H-thieno[2,3-e]1,2-thiazine-3-carboxamide 1,1-dioxide. Content: 99.0 per cent to 101.0 per cent (anhydrous substance). CHARACTERS Appearance Yellow, crystalline powder. Solubility Practically insoluble in water, sparingly soluble in methylene chloride,…<\/p>\n","protected":false},"author":5,"featured_media":28868,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-28864","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\/28864","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=28864"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/28864\/revisions"}],"predecessor-version":[{"id":28881,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/28864\/revisions\/28881"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/28868"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=28864"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=28864"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=28864"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}