﻿{"id":25814,"date":"2025-11-04T17:23:31","date_gmt":"2025-11-04T10:23:31","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=25814"},"modified":"2025-11-04T17:23:31","modified_gmt":"2025-11-04T10:23:31","slug":"ofloxacin","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/ofloxacin\/","title":{"rendered":"Ofloxacin"},"content":{"rendered":"<p><em>(Ph. Eur. monograph 1455)<\/em><\/p>\n<p>C<sub>18<\/sub>H<sub>20<\/sub>FN<sub>3<\/sub>O<sub>4<\/sub> 361.4 82419-36-1<\/p>\n<p><strong>Action and use<\/strong><\/p>\n<p>Fluoroquinolone antibacterial.<\/p>\n<p><strong>Preparations<\/strong><\/p>\n<p>Ofloxacin Eye Drops<\/p>\n<p>Ofloxacin Infusion<\/p>\n<p>Ofloxacin Tablets<\/p>\n<h2>DEFINITION<\/h2>\n<p>(3RS)-9-Fluoro-3-methyl-10-(4-methylpiperazin-1-yl)-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid.<\/p>\n<h3>Content<\/h3>\n<p>99.0 per cent to 101.0 per cent (dried substance).<\/p>\n<h3>CHARACTERS<\/h3>\n<h3>Appearance<\/h3>\n<p>Pale yellow or bright yellow, crystalline powder.<\/p>\n<h3>Solubility<\/h3>\n<p>Slightly soluble in water, soluble in glacial acetic acid, soluble or slightly soluble in methylene chloride, slightly soluble in methanol.<\/p>\n<h2>IDENTIFICATION<\/h2>\n<p>A. Infrared absorption spectrophotometry (2.2.24).<\/p>\n<p>Comparison: ofloxacin CRS.<\/p>\n<p>B. Optical rotation (see Tests).<\/p>\n<h2>TESTS<\/h2>\n<h3>Optical rotation (2.2.7)<\/h3>\n<p>-0.10\u00b0 to + 0.10\u00b0.<\/p>\n<p>Dissolve 0.300 g in a mixture of 10 volumes of methanol R and 40 volumes of methylene chloride R and dilute to 10.0 mL with the same mixture of solvents.<\/p>\n<h3>Absorbance (2.2.25)<\/h3>\n<p>Maximum 0.25 at 440 nm.<\/p>\n<p>Dissolve 0.5 g in a 10.3 g\/L solution of hydrochloric acid R and dilute to 100.0 mL with the same solution.<\/p>\n<h3>Related substances<\/h3>\n<p>Liquid chromatography (2.2.29).<\/p>\n<p>Solvent mixture acetonitrile R, water R (10:60 V\/V).<\/p>\n<p>Buffer solution: Dissolve 3.08 g of ammonium acetate R and 5.38 g of sodium perchlorate R in about 900 mL of water for chromatography R. Adjust to pH 2.2 with phosphoric acid R and dilute to 1000 mL with<br \/>\nwater for chromatography R.<\/p>\n<p>Test solution: Dissolve 20.0 mg of the substance to be examined in the solvent mixture and dilute to 50.0 mL with the solvent mixture.<\/p>\n<p>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<p>Reference solution (b): Dissolve 5.0 mg of levofloxacin impurity F CRS (ofloxacin impurity A; S-enantiomer) in 42 mL of acetonitrile R and dilute to 250.0 mL with water R. Dilute 1.0 mL of this solution to 25.0 mL with<br \/>\nthe solvent mixture.<\/p>\n<p>Reference solution (c): Dissolve 5 mg of ofloxacin impurity D CRS and 5 mg of ofloxacin impurity E CRS in the solvent mixture and dilute to 25 mL with the solvent mixture. Mix 2 mL of the solution and 1 mL of the<br \/>\ntest solution and dilute to 50 mL with the solvent mixture. Dilute 1 mL of this solution to 10 mL with the solvent mixture.<\/p>\n<p>Column:<\/p>\n<p>\u2014 size: l = 0.15 m, \u00d8 = 4.6 mm;<\/p>\n<p>\u2014 stationary phase: end-capped octadecylsilyl silica gel for chromatography R (3 \u03bcm);<\/p>\n<p>\u2014 temperature: 38 \u00b0C.<\/p>\n<p>Mobile phase:<\/p>\n<p>\u2014 mobile phase A: acetonitrile for chromatography R, buffer solution (16:84 V\/V);<\/p>\n<p>\u2014 mobile phase B: methanol R1, acetonitrile for chromatography R, buffer solution (20:30:50 V\/V\/V);<\/p>\n<table style=\"border-collapse: collapse; width: 100%; height: 127px;\">\n<tbody>\n<tr style=\"height: 43px;\">\n<td style=\"width: 33.3333%; height: 43px; text-align: center;\"><strong>Time<\/strong><br \/>\n<strong>(min)<\/strong><\/td>\n<td style=\"width: 33.3333%; height: 43px; text-align: center;\"><strong>Mobile phase A<\/strong><br \/>\n<strong>(per cent V\/V)<\/strong><\/td>\n<td style=\"width: 33.3333%; height: 43px; text-align: center;\"><strong>Mobile phase B<\/strong><br \/>\n<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;\">100<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">0<\/td>\n<\/tr>\n<tr style=\"height: 21px;\">\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">5 &#8211; 10<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">100 \u2192 82<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">0 \u2192 18<\/td>\n<\/tr>\n<tr style=\"height: 21px;\">\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">10 &#8211; 15<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">82 \u2192 40<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">18 \u2192 60<\/td>\n<\/tr>\n<tr style=\"height: 21px;\">\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">15 &#8211; 30<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">40<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">60<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Flow rate: 1.0 mL\/min.<\/p>\n<p>Detection: Spectrophotometer at 294 nm and, for impurity A, at 240 nm.<\/p>\n<p>Injection: 10 \u03bcL.<\/p>\n<p>Identification of impurities: Use the chromatogram obtained with reference solution (b) to identify the peak due to impurity A; use the chromatogram obtained with reference solution (c) to identify the peaks due to<br \/>\nimpurities D and E.<\/p>\n<p>Relative retention: With reference to ofloxacin (retention time = about 10 min): impurity D = about 0.7; impurity E = about 0.93; impurity A = about 2.8.<\/p>\n<p>System suitability:<\/p>\n<p>\u2014 resolution: minimum 2.0 between the peaks due to impurity E and ofloxacin in the chromatogram obtained with reference solution (c);<\/p>\n<p>\u2014 signal-to-noise ratio: minimum 90 for the principal peak in the chromatogram obtained with referencesolution (a).<\/p>\n<p>Calculation of percentage contents:<\/p>\n<p>\u2014 correction factor: multiply the peak area of impurity D by 4.5;<\/p>\n<p>\u2014 for impurity A, use the concentration of impurity A in reference solution (b) and the peak areas recorded at 240 nm;<\/p>\n<p>\u2014 for impurities other than A, use the concentration of ofloxacin in reference solution (a) and the peak areas recorded at 294 nm.<\/p>\n<p>Limits:<\/p>\n<p>\u2014 impurity A: maximum 0.2 per cent;<\/p>\n<p>\u2014 impurity D: maximum 0.10 per cent;<\/p>\n<p>\u2014 unspecified impurities: for each impurity, maximum 0.10 per cent;<\/p>\n<p>\u2014 total: maximum 0.4 per cent;<\/p>\n<p>\u2014 reporting threshold: 0.05 per cent.<\/p>\n<h3>Loss on drying (2.2.32)<\/h3>\n<p>Maximum 0.2 per cent, determined on 1.000 g by drying at 105 \u00b0C for 4 h.<\/p>\n<h3>Sulfated ash (2.4.14)<\/h3>\n<p>Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n<h2>ASSAY<\/h2>\n<p>Dissolve 0.300 g in 100 mL of anhydrous acetic acid R. Titrate with 0.1 M perchloric acid, determining the end-point potentiometrically (2.2.20).<\/p>\n<p>1 mL of 0.1 M perchloric acid is equivalent to 36.14 mg of C<sub>18<\/sub>H<sub>20<\/sub>FN<sub>3<\/sub>O<sub>4<\/sub>.<\/p>\n<h2>STORAGE<\/h2>\n<p>In an airtight container, protected from light.<\/p>\n<h2>IMPURITIES<\/h2>\n<p>Specified impurities A, D.<\/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.<\/p>\n<p>Control of impurities in substances for pharmaceutical use) B, C, E, F.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-25851\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/2-14-300x163.jpg\" alt=\"Ofloxacin \" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/2-14-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/2-14-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/2-14-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/2-14.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>A. (3RS)-9,10-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-25852\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/3-13-300x163.jpg\" alt=\"Ofloxacin \" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/3-13-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/3-13-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/3-13-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/3-13.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>B. (3RS)-9-fluoro-3-methyl-10-(4-methylpiperazin-1-yl)-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazin-7- one,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-25853\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/4-12-300x163.jpg\" alt=\"Ofloxacin \" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/4-12-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/4-12-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/4-12-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/4-12.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>C. (3RS)-3-methyl-10-(4-methylpiperazin-1-yl)-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6- carboxylic acid,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-25854\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/5-11-300x163.jpg\" alt=\"Ofloxacin \" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/5-11-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/5-11-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/5-11-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/5-11.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>D. (3RS)-10-fluoro-3-methyl-9-(4-methylpiperazin-1-yl)-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de] [1,4]benzoxazine-6-carboxylic acid,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-25855\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/6-9-300x163.jpg\" alt=\"Ofloxacin \" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/6-9-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/6-9-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/6-9-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/6-9.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>E. (3RS)-9-fluoro-3-methyl-7-oxo-10-(piperazin-1-yl)-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6- carboxylic acid,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-25856\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/7-8-300x163.jpg\" alt=\"Ofloxacin \" width=\"300\" height=\"163\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/7-8-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/7-8-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/7-8-768x416.jpg 768w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/7-8.jpg 1200w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>F. 4-[(3RS)-6-carboxy-9-fluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazin-10-yl]-1- methylpiperazine 1-oxide.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>(Ph. Eur. monograph 1455) C18H20FN3O4 361.4 82419-36-1 Action and use Fluoroquinolone antibacterial. Preparations Ofloxacin Eye Drops Ofloxacin Infusion Ofloxacin Tablets DEFINITION (3RS)-9-Fluoro-3-methyl-10-(4-methylpiperazin-1-yl)-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid. Content 99.0 per cent to 101.0 per cent (dried substance). CHARACTERS Appearance Pale yellow or bright yellow, crystalline powder. Solubility Slightly soluble in water, soluble in glacial acetic acid, soluble or slightly&#8230;<\/p>\n","protected":false},"author":4,"featured_media":25850,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-25814","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\/25814","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=25814"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/25814\/revisions"}],"predecessor-version":[{"id":25866,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/25814\/revisions\/25866"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/25850"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=25814"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=25814"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=25814"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}