{"id":25502,"date":"2025-11-04T15:15:40","date_gmt":"2025-11-04T08:15:40","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=25502"},"modified":"2025-11-04T16:24:43","modified_gmt":"2025-11-04T09:24:43","slug":"xylazine-hydrochloride","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/xylazine-hydrochloride\/","title":{"rendered":"Xylazine Hydrochloride"},"content":{"rendered":"

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

Action and use<\/p>\n

Analgesic.<\/p>\n

Ph Eur<\/p>\n

\n

DEFINITION<\/h2>\n

N-(2,6-Dimethylphenyl)-5,6-dihydro-4H-1,3-thiazin-2-amine hydrochloride.<\/p>\n

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

98.0 per cent to 102.0 per cent (dried substance).<\/p>\n

CHARACTERS<\/h2>\n

Appearance<\/h3>\n

White or almost white, crystalline powder, hygroscopic.<\/p>\n

Solubility<\/h3>\n

Freely soluble in water, very soluble in methanol, freely soluble in methylene chloride. It shows polymorphism (5.9).<\/p>\n

IDENTIFICATION<\/h2>\n

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

Comparison\u00a0 xylazine hydrochloride CRS.<\/em><\/p>\n

If the spectra obtained show differences, dissolve the substance to be examined and the reference substance separately in the minimum volume of water R, evaporate to dryness at 60 \u00b0C at a pressure of 10-20 kPa, and record new spectra using the residues.<\/p>\n

B. It gives reaction (a) of chlorides (2.3.1).<\/p>\n

TESTS<\/h2>\n

Solution S<\/h3>\n

Dissolve 5.0 g in carbon dioxide-free water R, heating at 60 \u00b0C if necessary; allow to cool and dilute to 50.0 mL with the same solvent.<\/p>\n

Appearance of solution<\/h3>\n

Solution S is not more opalescent than reference suspension II (2.2.1) and is colourless (2.2.2, Method II).<\/p>\n

pH (2.2.3)<\/strong><\/p>\n

4.0 to 5.5 for solution S.<\/p>\n

Related substances<\/h3>\n

Liquid chromatography (2.2.29). Prepare the solutions immediately before use.<\/p>\n

Solvent mixture<\/em>\u00a0 Mix 8 volumes of acetonitrile R, 30 volumes of methanol R and 62 volumes of a 2.72 g\/L solution of potassium dihydrogen phosphate R previously adjusted to pH 7.2 with dilute sodium hydroxide solution R.<\/p>\n

Test solution<\/em> Dissolve 0.100 g of the substance to be examined in the solvent mixture and dilute to 20.0 mL with the solvent mixture.<\/p>\n

Reference solution (a)<\/em> Dilute 1.0 mL of the test solution to 50.0 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)<\/em>\u00a0 Dissolve 5.0 mg of bupivacaine impurity F CRS (xylazine impurity A) in acetonitrile R and dilute to 100.0 mL with the same solvent.<\/p>\n

Reference solution (c)<\/em>\u00a0 Dilute 1.0 mL of reference solution (b) to 100.0 mL with the solvent mixture.<\/p>\n

Reference solution (d)<\/em> Dilute 1 mL of the test solution to 100 mL with the solvent mixture. Mix 10 mL of this solution with 10 mL of reference solution (b). Dilute 1 mL of this solution to 5 mL with the solvent mixture.<\/p>\n

Column:<\/em><\/p>\n

\u2014 size: l<\/em> = 0.15 m, \u00d8 = 3.9 mm;<\/p>\n

\u2014 stationary phase:<\/em> end-capped octylsilyl silica gel for chromatography with embedded polar groups R (5 \u00b5m);<\/p>\n

\u2014 temperature:<\/em> 40 \u00b0C.<\/p>\n

Mobile phase:<\/p>\n

\u2014 mobile phase A:<\/em> mix 30 volumes of methanol R1 and 70 volumes of a 2.72 g\/L solution of potassium dihydrogen phosphate R previously adjusted to pH 7.2 with dilute sodium hydroxide solution R;<\/p>\n

\u2014 mobile phase B:<\/em> methanol R1, acetonitrile for chromatography R (30:70 V\/V);<\/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 – 15<\/td>\n89 \u2192 28<\/td>\n11 \u2192 72<\/td>\n<\/tr>\n
15 – 21<\/td>\n28<\/td>\n72<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

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

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

Injection<\/em>\u00a0 20 \u00b5L of the test solution and reference solutions (a), (c) and (d).<\/p>\n

Identification of impurities<\/em> Use the chromatogram obtained with reference solution (c) to identify the peak due to impurity A.<\/p>\n

Relative retention<\/em>\u00a0 With reference to xylazine (retention time = about 8 min): impurity A = about 0.8.<\/p>\n

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

\u2014 resolution:<\/em> minimum 4.0 between the peaks due to impurity A and xylazine.<\/p>\n

Calculation of percentage contents:<\/em><\/p>\n

\u2014 for impurity A, use the concentration of impurity A in reference solution (c);<\/p>\n

\u2014 for impurities other than A, use the concentration of xylazine hydrochloride in reference solution (a).<\/p>\n

Limits:<\/em><\/p>\n

\u2014 impurity A:<\/em> maximum 0.01 per cent;<\/p>\n

\u2014 unspecified impurities:<\/em> for each impurity, maximum 0.20 per cent;<\/p>\n

\u2014 total:<\/em> maximum 0.2 per cent;<\/p>\n

\u2014 reporting threshold:<\/em> 0.10 per cent, except for impurity A.<\/p>\n

Loss on drying (2.2.32)<\/strong><\/p>\n

Maximum 0.5 per cent, determined on 1.000 g by drying in an oven at 105 \u00b0C for 2 h.<\/p>\n

Sulfated ash (2.4.14)<\/strong><\/p>\n

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

ASSAY<\/h2>\n

Dissolve 0.200 g in 25 mL of ethanol (96 per cent) R. Add 25 mL of water R. Titrate with 0.1 M sodium hydroxide, determining the end-point potentiometrically (2.2.20).<\/p>\n

1 mL of 0.1 M sodium hydroxide is equivalent to 25.68 mg of C12<\/sub>H17<\/sub>ClN2<\/sub>S.<\/p>\n

STORAGE<\/h2>\n

In an airtight container, protected from light.<\/p>\n

IMPURITIES<\/h2>\n

Specified impurities\u00a0 A.<\/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) B, C, D.<\/em><\/p>\n

\"Xylazine<\/p>\n

A. 2,6-dimethylaniline (2,6-xylidine),<\/p>\n

\"Xylazine<\/p>\n

B. N,N\u2032-bis(2,6-dimethylphenyl)thiourea,<\/p>\n

\"Xylazine<\/p>\n

C. 1-isothiocyanato-2,6-dimethylbenzene,<\/p>\n

\"Xylazine<\/p>\n

D. N-(2,6-dimethylphenyl)-N\u2032-(3-hydroxypropyl)thiourea.<\/p>\n","protected":false},"excerpt":{"rendered":"

Edition: BP 2025 (Ph. Eur. 11.6 update) Action and use Analgesic. Ph Eur DEFINITION N-(2,6-Dimethylphenyl)-5,6-dihydro-4H-1,3-thiazin-2-amine hydrochloride. Content 98.0 per cent to 102.0 per cent (dried substance). CHARACTERS Appearance White or almost white, crystalline powder, hygroscopic. Solubility Freely soluble in water, very soluble in methanol, freely soluble in methylene chloride. It shows polymorphism (5.9). IDENTIFICATION A….<\/p>\n","protected":false},"author":5,"featured_media":25503,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[176],"tags":[],"class_list":["post-25502","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\/25502","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=25502"}],"version-history":[{"count":4,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/25502\/revisions"}],"predecessor-version":[{"id":25690,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/25502\/revisions\/25690"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/25503"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=25502"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=25502"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=25502"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}