{"id":31433,"date":"2025-11-13T16:09:00","date_gmt":"2025-11-13T09:09:00","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=31433"},"modified":"2025-11-13T16:09:00","modified_gmt":"2025-11-13T09:09:00","slug":"tolnaftate","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/tolnaftate\/","title":{"rendered":"Tolnaftate"},"content":{"rendered":"<p>Edition: BP 2025 (Ph. Eur. 11.6 update)<\/p>\n<p>C<sub>19<\/sub>H<sub>17<\/sub>NOS 307.4 2398-96-1<\/p>\n<p><strong>Action and use<\/strong><\/p>\n<p>Antifungal.<\/p>\n<h2>DEFINITION<\/h2>\n<p>O-Naphthalen-2-yl methyl(3-methylphenyl)carbamothioate.<\/p>\n<p><strong>Content<\/strong><\/p>\n<p>97.0 per cent to 103.0 per cent (dried substance).<\/p>\n<h2>CHARACTERS<\/h2>\n<h3>Appearance<\/h3>\n<p>White or yellowish-white powder.<\/p>\n<h3>Solubility<\/h3>\n<p>Practically insoluble in water, freely soluble in acetone and in methylene chloride, very slightly soluble in ethanol (96 per cent).<\/p>\n<h2>IDENTIFICATION<\/h2>\n<p>Infrared absorption spectrophotometry (2.2.24).<\/p>\n<p>Comparison tolnaftate CRS.<\/p>\n<h2>TESTS<\/h2>\n<h3>Impurity D<\/h3>\n<p>Liquid chromatography (2.2.29).<\/p>\n<p>Test solution Dissolve 0.400 g of the substance to be examined in 2 mL of methylene chloride R. Extract with 3 quantities, each of 3 mL, of 0.01 M hydrochloric acid. Combine the aqueous phases and dilute to 10.0 mL with 0.01 M hydrochloric acid.<\/p>\n<p>Reference solution (a) Dissolve 20.0 mg of N-methyl-m-toluidine R (impurity D) in 50.0 mL of methylene chloride R.<\/p>\n<p>Reference solution (b) Dilute 1.0 mL of reference solution (a) to 100.0 mL with methylene chloride R. Take 2.0 mL of this solution and extract with 3 quantities, each of 3 mL, of 0.01 M hydrochloric acid. Combine the aqueous phases and dilute to 10.0 mL with 0.01 M hydrochloric acid.<\/p>\n<p>Reference solution (c) Dissolve 10 mg of the substance to be examined in 25 mL of methanol R. Add 2 mL of this solution to 2 mL of reference solution (a) and dilute to 25 mL with methanol R.<\/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:<\/p>\n<p>\u2014 mobile phase A: trifluoroacetic acid R, methanol R, water R (0.1:10:90 V\/V\/V);<\/p>\n<p>\u2014 mobile phase B: trifluoroacetic acid R, water R, methanol R (0.1:10:90 V\/V\/V);<\/p>\n<table style=\"border-collapse: collapse; width: 100%;\">\n<tbody>\n<tr>\n<td style=\"width: 33.3333%; text-align: center;\"><strong>Time<\/strong><\/p>\n<p><strong>(min)<\/strong><\/td>\n<td style=\"width: 33.3333%; text-align: center;\"><strong>Mobile phase A<\/strong><\/p>\n<p><strong>(per cent V\/V)<\/strong><\/td>\n<td style=\"width: 33.3333%; text-align: center;\"><strong>Mobile phase B<\/strong><\/p>\n<p><strong>(per cent V\/V)<\/strong><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 33.3333%; text-align: center;\">0 &#8211; 3<\/p>\n<p>3 &#8211; 8<\/p>\n<p>8 &#8211; 20<\/td>\n<td style=\"width: 33.3333%; text-align: center;\">70<\/p>\n<p>70 \u2192 0<\/p>\n<p>0<\/td>\n<td style=\"width: 33.3333%; text-align: center;\">30<\/p>\n<p>30 \u2192 100<\/p>\n<p>100<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Flow rate 1.0 mL\/min.<\/p>\n<p>Detection Spectrophotometer at 254 nm.<\/p>\n<p>Injection 100 \u03bcL of the test solution and reference solution (b); 10 \u03bcL of reference solution (c).<\/p>\n<p>Relative retention With reference to tolnaftate (retention time = about 15 min): impurity D = about 0.25.<\/p>\n<p>System suitability:<\/p>\n<p>\u2014 resolution: minimum 5.0 between the peaks due to impurity D and tolnaftate in the chromatogram obtained with reference solution (c);<\/p>\n<p>\u2014 symmetry factor: maximum 1.9 for the peak due to impurity D in the chromatogram obtained with reference solution (b).<\/p>\n<p>Limit:<\/p>\n<p>\u2014 impurity D: not more than the area of the principal peak in the chromatogram obtained with reference solution (b) (20 ppm).<\/p>\n<h3>Related substances<\/h3>\n<p>Liquid chromatography (2.2.29).<\/p>\n<p>Test solution Dissolve 25 mg of the substance to be examined in 5 mL of methanol R and dilute to 25.0 mL with the same solvent.<\/p>\n<p>Reference solution (a) Dilute 1.0 mL of the test solution to 100.0 mL with methanol R. Dilute 1.0 mL of this solution to 10.0 mL with methanol R.<\/p>\n<p>Reference solution (b) Dissolve 5 mg of tolnaftate for system suitability CRS (containing resolution component A) in 5.0 mL of methanol R.<\/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:<\/p>\n<p>\u2014 mobile phase A: trifluoroacetic acid R, water R, methanol R (0.1:30:70 V\/V\/V);<\/p>\n<p>\u2014 mobile phase B: trifluoroacetic acid R, water R, methanol R (0.1:10:90 V\/V\/V);<\/p>\n<table style=\"border-collapse: collapse; width: 100%;\">\n<tbody>\n<tr>\n<td style=\"width: 33.3333%; text-align: center;\"><strong>Time<\/strong><\/p>\n<p><strong>(min)<\/strong><\/td>\n<td style=\"width: 33.3333%; text-align: center;\"><strong>Mobile phase A<\/strong><\/p>\n<p><strong>(per cent V\/V)<\/strong><\/td>\n<td style=\"width: 33.3333%; text-align: center;\"><strong>Mobile phase B<\/strong><\/p>\n<p><strong>(per cent V\/V)<\/strong><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 33.3333%; text-align: center;\">0 &#8211; 12<\/p>\n<p>12 &#8211; 30<\/p>\n<p>30 &#8211; 33<\/td>\n<td style=\"width: 33.3333%; text-align: center;\">100<\/p>\n<p>100 \u2192 0<\/p>\n<p>0<\/td>\n<td style=\"width: 33.3333%; text-align: center;\">0<\/p>\n<p>0 \u2192 100<\/p>\n<p>100<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Flow rate 1.0 mL\/ min.<\/p>\n<p>Detection Spectrophotometer at 254 nm.<\/p>\n<p>Injection 10 \u03bcL.<\/p>\n<p>Relative retention With reference to tolnaftate (retention time = about 18 min): resolution component A = about 0.7.<\/p>\n<p>System suitability Reference solution (b):<\/p>\n<p>\u2014 resolution: minimum 5.0 between the peaks due to resolution component A and tolnaftate.<\/p>\n<p>Limits:<\/p>\n<p>\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<p>\u2014 total: not more than twice the area of the principal peak in the chromatogram obtained with reference solution (a) (0.2 per cent);<\/p>\n<p>\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<p>Loss on drying (2.2.32)<\/p>\n<p>Maximum 0.5 per cent, determined on 1.000 g by drying at 60 \u00b0C at a pressure not exceeding 0.7 kPa for 3 h.<\/p>\n<p>Sulfated ash (2.4.14)<\/p>\n<p>Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n<h2>ASSAY<\/h2>\n<p>Dissolve 50.0 mg in methanol R and dilute to 250.0 mL with the same solvent. Dilute 2.0 mL of this solution to 50.0 mL with methanol R. Measure the absorbance (2.2.25) at the absorption maximum at 257 nm.<\/p>\n<p>Calculate the content of C<sub>19<\/sub>H<sub>17<\/sub>NOS taking the specific absorbance to be 720.<\/p>\n<p>STORAGE<\/p>\n<p>Protected from light.<\/p>\n<h2>IMPURITIES<\/h2>\n<p>Specified impurities 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. Control of impurities in substances for pharmaceutical use) A, B.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-31465\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-1.jpg\" alt=\"Tolnaftate\" width=\"1200\" height=\"650\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-1.jpg 1200w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-1-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-1-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-1-768x416.jpg 768w\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" \/><\/p>\n<p>A. naphthalen-2-ol (\u03b2-naphthol),<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-31467\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-3.jpg\" alt=\"Tolnaftate\" width=\"1200\" height=\"650\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-3.jpg 1200w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-3-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-3-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-3-768x416.jpg 768w\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" \/><\/p>\n<p>B. O,O-dinaphthalen-2-yl carbonothioate,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-31466\" src=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-2.jpg\" alt=\"Tolnaftate\" width=\"1200\" height=\"650\" srcset=\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-2.jpg 1200w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-2-300x163.jpg 300w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-2-1024x555.jpg 1024w, https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Tolnaftate-2-768x416.jpg 768w\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" \/><\/p>\n<p>D. N,3-dimethylaniline (N-methyl-m-toluidine).<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Edition: BP 2025 (Ph. Eur. 11.6 update) C19H17NOS 307.4 2398-96-1 Action and use Antifungal. DEFINITION O-Naphthalen-2-yl methyl(3-methylphenyl)carbamothioate. Content 97.0 per cent to 103.0 per cent (dried substance). CHARACTERS Appearance White or yellowish-white powder. Solubility Practically insoluble in water, freely soluble in acetone and in methylene chloride, very slightly soluble in ethanol (96 per cent). IDENTIFICATION&#8230;<\/p>\n","protected":false},"author":5,"featured_media":31464,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-31433","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\/31433","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=31433"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/31433\/revisions"}],"predecessor-version":[{"id":31478,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/31433\/revisions\/31478"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/31464"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=31433"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=31433"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=31433"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}