{"id":23415,"date":"2025-10-31T17:28:55","date_gmt":"2025-10-31T10:28:55","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=23415"},"modified":"2025-10-31T17:59:06","modified_gmt":"2025-10-31T10:59:06","slug":"diclazuril","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/diclazuril\/","title":{"rendered":"Diclazuril"},"content":{"rendered":"

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

DEFINITION<\/h2>\n

(RS)-(4-Chlorophenyl)[2,6-dichloro-4-(3,5-dioxo-4,5-dihydro-1,2,4-triazin-2(3H)-yl)phenyl]acetonitrile.<\/p>\n

Content<\/strong><\/p>\n

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

CHARACTERS<\/h2>\n

Appearance<\/h3>\n

White or light yellow powder.<\/p>\n

Solubility<\/h3>\n

Practically insoluble in water, sparingly soluble in dimethylformamide, practically insoluble in ethanol (96 per cent) and in methylene chloride.<\/p>\n

IDENTIFICATION<\/h2>\n

Infrared absorption spectrophotometry (2.2.24).<\/p>\n

Comparison\u00a0 diclazuril CRS.<\/p>\n

TESTS<\/h2>\n

Related substances<\/h3>\n

Liquid chromatography (2.2.29).<\/p>\n

Test solution Dissolve 20.0 mg of the substance to be examined in dimethylformamide R and dilute to 20.0 mL with the same solvent.<\/p>\n

Reference solution (a)\u00a0 Dissolve 5 mg of diclazuril for system suitability CRS (containing impurity D) in
\ndimethylformamide R and dilute to 5 mL with the same solvent.<\/p>\n

Reference solution (b) Dilute 1.0 mL of the test solution to 100.0 mL with dimethylformamide R. Dilute 1.0 mL of the solution to 10.0 mL with dimethylformamide R.<\/p>\n

Column:<\/p>\n

\u2014 size: l = 0.10 m, \u00d8 = 4.6 mm;<\/p>\n

\u2014 stationary phase: base-deactivated end-capped octadecylsilyl silica gel for chromatography R (3 \u00b5m);<\/p>\n

\u2014 temperature: 35 \u00b0C.<\/p>\n

Mobile phase:<\/p>\n

\u2014 mobile phase A: mix 10 volumes of a 6.3 g\/L solution of ammonium formate R adjusted to pH 4.0 with formic acid R, 15 volumes of acetonitrile for chromatography R and 75 volumes of water for chromatography R;<\/p>\n

\u2014 mobile phase B: mix 10 volumes of a 6.3 g\/L solution of ammonium formate R adjusted to pH 4.0 with formic acid R, 85 volumes of acetonitrile for chromatography R and 5 volumes of water for chromatography R;<\/p>\n\n\n\n\n\n
Time (min)<\/strong><\/td>\nMobile phase A (per cent V\/V)<\/strong><\/td>\nMobile phase B (per cent V\/V)<\/strong><\/td>\n<\/tr>\n
0 – 20<\/td>\n100 \u2192 0<\/td>\n0 \u2192 100<\/td>\n<\/tr>\n
20 – 25<\/td>\n0<\/td>\n100<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Flow rate\u00a0 1.0 mL\/min.<\/p>\n

Detection\u00a0 Spectrophotometer at 230 nm.<\/p>\n

Injection\u00a0 5 \u00b5L.<\/p>\n

System suitability\u00a0 Reference solution (a):<\/p>\n

\u2014 peak-to-valley ratio: minimum 1.5, where Hp = height above the baseline of the peak due to impurity D and<\/p>\n

Hv = height above the baseline of the lowest point of the curve separating this peak from the peak due to diclazuril.<\/p>\n

Identification of impurities Use the chromatogram supplied with diclazuril for system suitability CRS and the chromatogram obtained with reference solution (a) to identify the peak due to impurity D.<\/p>\n

Relative retention\u00a0 With reference to diclazuril (retention time = about 14 min): impurity D = about 1.03.<\/p>\n

Limits:<\/p>\n

\u2014 correction factor: for the calculation of content, multiply the peak area of impurity D by 1.9;<\/p>\n

\u2014 impurity D: not more than the area of the principal peak in the chromatogram obtained with reference solution (b) (0.1 per cent);<\/p>\n

\u2014 unspecified impurities: for each impurity, not more than twice the area of the principal peak in the chromatogram obtained with reference solution (b) (0.20 per cent);<\/p>\n

\u2014 total: not more than 7 times the area of the principal peak in the chromatogram obtained with reference solution (b) (0.7 per cent);<\/p>\n

\u2014 disregard limit: the area of the principal peak in the chromatogram obtained with reference solution (b) (0,10 per cent); do not disregard the peak due to impurity D.<\/p>\n

Loss on drying (2.2.32)<\/h3>\n

Maximum 0.5 per cent, determined on 1.000 g by drying in an oven at 105 \u00b0C for 4 h.<\/p>\n

Sulfated ash (2.4.14)<\/h3>\n

Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n

ASSAY<\/h2>\n

Dissolve 0.150 g in 75 mL of dimethylformamide R. Carry out a potentiometric titration (2.2.20), using 0.1 M tetrabutylammonium hydroxide. Read the volume added at the second inflexion point. Carry out a blank titration.<\/p>\n

1 mL of 0.1 M tetrabutylammonium hydroxide is equivalent to 20.38 mg of C17H9Cl3N4O2.<\/p>\n

STORAGE<\/h2>\n

Protected from light.<\/p>\n

IMPURITIES<\/h2>\n

Specified impurities\u00a0 D.<\/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. Control of impurities in substances for pharmaceutical use) A, B, C, E, F, G, H, I.<\/em><\/p>\n

\"Diclazuril\"<\/p>\n

A. 2-[3,5-dichloro-4-[(RS)-(4-chlorophenyl)cyanomethyl]phenyl]-3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazine-6-carboxylic\u00a0 acid,<\/p>\n

\"Diclazuril\"<\/p>\n

B. (RS)-[2,6-dichloro-4-(3,5-dioxo-4,5-dihydro-1,2,4-triazin-2(3H)-yl)phenyl](4-hydroxyphenyl)acetonitrile,<\/p>\n

\"Diclazuril\"<\/p>\n

C. 2-[3,5-dichloro-4-[(RS)-(4-chlorophenyl)cyanomethyl]phenyl]-3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazine-6- carboxamide,<\/p>\n

\"Diclazuril\"<\/p>\n

D. 2-[3,5-dichloro-4-(4-chlorobenzoyl)phenyl]-1,2,4-triazine-3,5(2H,4H)-dione,<\/p>\n

\"Diclazuril\"<\/p>\n

E. (RS)-(4-amino-2,6-dichlorophenyl)(4-chlorophenyl)acetonitrile,<\/p>\n

\"Diclazuril\"<\/p>\n

F. 2-[3,5-dichloro-4-[(4-chlorophenyl)methyl]phenyl]-1,2,4-triazine-3,5(2H,4H)-dione,<\/p>\n

\"Diclazuril\"<\/p>\n

G. butyl 2-[3,5-dichloro-4-[(RS)-(4-chlorophenyl)cyanomethyl]phenyl]-3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazine-6- carboxylate,<\/p>\n

\"Diclazuril\"<\/p>\n

H. (RS)-(4-chlorophenyl)(2,6-dichlorophenyl)acetonitrile,<\/p>\n

\"Diclazuril\"<\/p>\n

I. N,2-bis[3,5-dichloro-4-[(\u039e)-(4-chlorophenyl)cyanomethyl]phenyl]-3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazine-6- carboxamide.<\/p>\n","protected":false},"excerpt":{"rendered":"

Edition: BP 2025 (Ph. Eur. 11.6 update) DEFINITION (RS)-(4-Chlorophenyl)[2,6-dichloro-4-(3,5-dioxo-4,5-dihydro-1,2,4-triazin-2(3H)-yl)phenyl]acetonitrile. Content 99.0 per cent to 101.0 per cent (dried substance). CHARACTERS Appearance White or light yellow powder. Solubility Practically insoluble in water, sparingly soluble in dimethylformamide, practically insoluble in ethanol (96 per cent) and in methylene chloride. IDENTIFICATION Infrared absorption spectrophotometry (2.2.24). Comparison\u00a0 diclazuril CRS. TESTS…<\/p>\n","protected":false},"author":5,"featured_media":23416,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[176],"tags":[],"class_list":["post-23415","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-british-pharmacopoeia-veterinary-2020"],"acf":[],"_links":{"self":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/23415","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=23415"}],"version-history":[{"count":4,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/23415\/revisions"}],"predecessor-version":[{"id":23468,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/23415\/revisions\/23468"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/23416"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=23415"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=23415"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=23415"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}