{"id":9936,"date":"2025-10-07T11:11:35","date_gmt":"2025-10-07T04:11:35","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=9936"},"modified":"2025-10-07T11:11:35","modified_gmt":"2025-10-07T04:11:35","slug":"dapsone","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/dapsone\/","title":{"rendered":"Dapsone"},"content":{"rendered":"

(Ph. Eur. monograph 0077)<\/p>\n

C_{12<\/sub>H_{12<\/sub>N_{2<\/sub>O_{2<\/sub>S\u00a0 \u00a0 \u00a0 \u00a0248.3\u00a0 \u00a0 \u00a0 \u00a080-08-0<\/p>\n}}}}

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

Folic acid synthesis inhibitor; treatment of leprosy.<\/p>\n

Preparation<\/strong><\/p>\n

Dapsone Tablets<\/p>\n

DEFINITION<\/h2>\n
4,4\u2032-Sulfonyldianiline.<\/p>\n
Content<\/h3>\n
99.0 per cent to 101.0 per cent (dried substance).<\/p>\n
CHARACTERS<\/h2>\n
Appearance<\/h3>\n
White or slightly yellowish-white, crystalline powder.<\/p>\n
Solubility<\/h3>\n
Practically insoluble in water, freely soluble in acetone, sparingly soluble in ethanol (96 per cent). It dissolves in dilute mineral acids.<\/p>\n
It shows polymorphism (5.9).<\/p>\n
IDENTIFICATION<\/h2>\n
Infrared absorption spectrophotometry (2.2.24).<\/p>\n
Comparison: dapsone CRS.<\/p>\n
If the spectra obtained in the solid state show differences, dissolve the substance to be examined and the reference substance separately in acetone R, evaporate to dryness and record new spectra using the residues.<\/p>\n
TESTS<\/h2>\n
Related substances<\/h3>\n
Liquid chromatography (2.2.29).<\/p>\n
Solvent mixture: acetonitrile R, water R (50:50 V\/V).<\/p>\n
Test solution: Dissolve 40.0 mg of the substance to be examined in 30 mL of the solvent mixture and dilute to 100.0 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 2 mg of the substance to be examined, 2 mg of 4-(4-aminobenzene-1-sulfonyl)phenol R, 2 mg of 4-(benzenesulfonyl)aniline R and 2 mg of 4,4\u2032-[oxybis[(4,1-phenylene)sulfonyl]]dianiline R (impurity C) in the solvent mixture and dilute to 50 mL with the solvent mixture. Dilute 1 mL of the solution to 10 mL with the solvent mixture.<\/p>\n
Column:<\/p>\n
\u2014 size: l = 0.25 m, \u00d8 = 4.6 mm;<\/p>\n
\u2014 stationary phase: end-capped octadecylsilyl silica gel for chromatography R (5 \u03bcm).<\/p>\n
Mobile phase:<\/p>\n
\u2014 mobile phase A: water for chromatography R;<\/p>\n
\u2014 mobile phase B: acetonitrile R;<\/p>\n\n\n\n\n\n\n
Time<\/strong>
\n(min)<\/strong><\/td>\n Mobile phase A<\/strong>
\n(per cent V\/V)<\/strong><\/td>\n Mobile phase B<\/strong>
\n(per cent V\/V)<\/strong><\/td>\n<\/tr>\n
0 – 10<\/td>\n 75<\/td>\n 25<\/td>\n<\/tr>\n
10 – 20<\/td>\n 75 \u2192 50<\/td>\n 25 \u2192 50<\/td>\n<\/tr>\n
20 – 35<\/td>\n 50<\/td>\n 50<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
Flow rate: 1.0 mL\/min.<\/p>\n
Detection: Spectrophotometer at 254 nm.<\/p>\n
Injection: 20 \u03bcL.<\/p>\n
Identification of impurities: Use the chromatogram obtained with reference solution (b) to identify the peaks due to impurities A, B and C.<\/p>\n
Relative retention: With reference to dapsone (retention time = about 7 min): impurity A = about 1.1; impurity B = about 2.5; impurity C = about 3.5.<\/p>\n
System suitability: Reference solution (b):<\/p>\n
\u2014 resolution: minimum 2.0 between the peaks due to dapsone and impurity A.<\/p>\n
Calculation of percentage contents:<\/p>\n
\u2014 correction factors: multiply the peak areas of the following impurities by the corresponding correction factor: impurity A = 1.9; impurity B = 2.7; impurity C = 1.7;<\/p>\n
\u2014 for each impurity, use the concentration of dapsone in reference solution (a).<\/p>\n
Limits:<\/p>\n
\u2014 impurity B: maximum 0.4 per cent;<\/p>\n
\u2014 impurities A, C: for each impurity, maximum 0.3 per cent;<\/p>\n
\u2014 unspecified impurities: for each impurity, maximum 0.10 per cent;<\/p>\n
\u2014 total: maximum 1.0 per cent;<\/p>\n
\u2014 reporting threshold: 0.05 per cent.<\/p>\n
Loss on drying (2.2.32)<\/h4>\n
Maximum 1.5 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
Carry out the determination of primary aromatic amino-nitrogen (2.5.8), using 0.100 g.<\/p>\n
1 mL of 0.1 M sodium nitrite is equivalent to 12.42 mg of C_{12<\/sub>H_{12<\/sub>N_{2<\/sub>O_{2<\/sub>S.<\/p>\n}}}}
STORAGE<\/h2>\n
Protected from light.<\/p>\n
IMPURITIES<\/h2>\n
Specified impurities A, B, C.<\/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).<\/p>\n
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) D, E, F.<\/p>\n
$\"Dapsone\"$ <\/p>\n
A. 4-(4-aminobenzene-1-sulfonyl)phenol,<\/p>\n
$\"Dapsone\"$ <\/p>\n
B. 4-(benzenesulfonyl)aniline,<\/p>\n
$\"Dapsone\"$ <\/p>\n
C. 1 ,7 -diamino-4-oxa-2\u03bb ,6\u03bb -dithia-1,7(1),3,5(1,4)-tetrabenzenaheptaphane-2,2,6,6-tetrone,<\/p>\n
$\"Dapsone\"$ <\/p>\n
D. 2-(4-aminobenzene-1-sulfonyl)aniline,<\/p>\n
$\"Dapsone\"$ <\/p>\n
E. 4-(4-chlorobenzene-1-sulfonyl)aniline,<\/p>\n
$\"Dapsone\"$ <\/p>\n
F. 1-(benzenesulfonyl)-4-chlorobenzene.<\/p>\n","protected":false},"excerpt":{"rendered":"
(Ph. Eur. monograph 0077) C12H12N2O2S\u00a0 \u00a0 \u00a0 \u00a0248.3\u00a0 \u00a0 \u00a0 \u00a080-08-0 Action and use Folic acid synthesis inhibitor; treatment of leprosy. Preparation Dapsone Tablets DEFINITION 4,4\u2032-Sulfonyldianiline. Content 99.0 per cent to 101.0 per cent (dried substance). CHARACTERS Appearance White or slightly yellowish-white, crystalline powder. Solubility Practically insoluble in water, freely soluble in acetone, sparingly soluble…<\/p>\n","protected":false},"author":2,"featured_media":9978,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-9936","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\/9936","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=9936"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/9936\/revisions"}],"predecessor-version":[{"id":9990,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/9936\/revisions\/9990"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/9978"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=9936"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=9936"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=9936"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

Time<\/strong> \n(min)<\/strong><\/td>\n	Mobile phase A<\/strong> \n(per cent V\/V)<\/strong><\/td>\n	Mobile phase B<\/strong> \n(per cent V\/V)<\/strong><\/td>\n<\/tr>\n
0 – 10<\/td>\n	75<\/td>\n	25<\/td>\n<\/tr>\n
10 – 20<\/td>\n	75 \u2192 50<\/td>\n	25 \u2192 50<\/td>\n<\/tr>\n
20 – 35<\/td>\n	50<\/td>\n	50<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Flow rate: 1.0 mL\/min.<\/p>\n Detection: Spectrophotometer at 254 nm.<\/p>\n Injection: 20 \u03bcL.<\/p>\n Identification of impurities: Use the chromatogram obtained with reference solution (b) to identify the peaks due to impurities A, B and C.<\/p>\n Relative retention: With reference to dapsone (retention time = about 7 min): impurity A = about 1.1; impurity B = about 2.5; impurity C = about 3.5.<\/p>\n System suitability: Reference solution (b):<\/p>\n \u2014 resolution: minimum 2.0 between the peaks due to dapsone and impurity A.<\/p>\n Calculation of percentage contents:<\/p>\n \u2014 correction factors: multiply the peak areas of the following impurities by the corresponding correction factor: impurity A = 1.9; impurity B = 2.7; impurity C = 1.7;<\/p>\n \u2014 for each impurity, use the concentration of dapsone in reference solution (a).<\/p>\n Limits:<\/p>\n \u2014 impurity B: maximum 0.4 per cent;<\/p>\n \u2014 impurities A, C: for each impurity, maximum 0.3 per cent;<\/p>\n \u2014 unspecified impurities: for each impurity, maximum 0.10 per cent;<\/p>\n \u2014 total: maximum 1.0 per cent;<\/p>\n \u2014 reporting threshold: 0.05 per cent.<\/p>\n Loss on drying (2.2.32)<\/h4>\n Maximum 1.5 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 Carry out the determination of primary aromatic amino-nitrogen (2.5.8), using 0.100 g.<\/p>\n 1 mL of 0.1 M sodium nitrite is equivalent to 12.42 mg of C_{12<\/sub>H_{12<\/sub>N_{2<\/sub>O_{2<\/sub>S.<\/p>\n}}}} STORAGE<\/h2>\n Protected from light.<\/p>\n IMPURITIES<\/h2>\n Specified impurities A, B, C.<\/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).<\/p>\n 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) D, E, F.<\/p>\n $\"Dapsone\"$ <\/p>\n A. 4-(4-aminobenzene-1-sulfonyl)phenol,<\/p>\n $\"Dapsone\"$ <\/p>\n B. 4-(benzenesulfonyl)aniline,<\/p>\n $\"Dapsone\"$ <\/p>\n C. 1 ,7 -diamino-4-oxa-2\u03bb ,6\u03bb -dithia-1,7(1),3,5(1,4)-tetrabenzenaheptaphane-2,2,6,6-tetrone,<\/p>\n $\"Dapsone\"$ <\/p>\n D. 2-(4-aminobenzene-1-sulfonyl)aniline,<\/p>\n $\"Dapsone\"$ <\/p>\n E. 4-(4-chlorobenzene-1-sulfonyl)aniline,<\/p>\n $\"Dapsone\"$ <\/p>\n F. 1-(benzenesulfonyl)-4-chlorobenzene.<\/p>\n","protected":false},"excerpt":{"rendered":" (Ph. Eur. monograph 0077) C12H12N2O2S\u00a0 \u00a0 \u00a0 \u00a0248.3\u00a0 \u00a0 \u00a0 \u00a080-08-0 Action and use Folic acid synthesis inhibitor; treatment of leprosy. Preparation Dapsone Tablets DEFINITION 4,4\u2032-Sulfonyldianiline. Content 99.0 per cent to 101.0 per cent (dried substance). CHARACTERS Appearance White or slightly yellowish-white, crystalline powder. Solubility Practically insoluble in water, freely soluble in acetone, sparingly soluble…<\/p>\n","protected":false},"author":2,"featured_media":9978,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-9936","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\/9936","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=9936"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/9936\/revisions"}],"predecessor-version":[{"id":9990,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/9936\/revisions\/9990"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/9978"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=9936"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=9936"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=9936"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

Content<\/h3>\n99.0 per cent to 101.0 per cent (dried substance).<\/p>\n

CHARACTERS<\/h2>\n

Appearance<\/h3>\nWhite or slightly yellowish-white, crystalline powder.<\/p>\n

Solubility<\/h3>\nPractically insoluble in water, freely soluble in acetone, sparingly soluble in ethanol (96 per cent). It dissolves in dilute mineral acids.<\/p>\nIt shows polymorphism (5.9).<\/p>\n

TESTS<\/h2>\n

Loss on drying (2.2.32)<\/h4>\nMaximum 1.5 per cent, determined on 1.000 g by drying in an oven at 105 \u00b0C.<\/p>\n

Sulfated ash (2.4.14)<\/h4>\nMaximum 0.1 per cent, determined on 1.0 g.<\/p>\n

ASSAY<\/h2>\nCarry out the determination of primary aromatic amino-nitrogen (2.5.8), using 0.100 g.<\/p>\n1 mL of 0.1 M sodium nitrite is equivalent to 12.42 mg of C12<\/sub>H12<\/sub>N2<\/sub>O2<\/sub>S.<\/p>\n

STORAGE<\/h2>\nProtected from light.<\/p>\n

Content<\/h3>\n
99.0 per cent to 101.0 per cent (dried substance).<\/p>\n

Appearance<\/h3>\n
White or slightly yellowish-white, crystalline powder.<\/p>\n

Solubility<\/h3>\n
Practically insoluble in water, freely soluble in acetone, sparingly soluble in ethanol (96 per cent). It dissolves in dilute mineral acids.<\/p>\n
It shows polymorphism (5.9).<\/p>\n

Loss on drying (2.2.32)<\/h4>\n
Maximum 1.5 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
Carry out the determination of primary aromatic amino-nitrogen (2.5.8), using 0.100 g.<\/p>\n
1 mL of 0.1 M sodium nitrite is equivalent to 12.42 mg of C_{12<\/sub>H_{12<\/sub>N_{2<\/sub>O_{2<\/sub>S.<\/p>\n}}}}

STORAGE<\/h2>\n
Protected from light.<\/p>\n