Action and use<\/strong><\/p>\n Antihistamine.<\/p>\n (13bRS)-9,13b-Dihydro-1H-dibenzo[c,f]imidazo[1,5-a]azepin-3-amine hydrochloride.<\/p>\n 99.0 per cent to 101.0 per cent (dried substance).<\/p>\n White or almost white, hygroscopic, crystalline powder.<\/p>\n Solubility<\/p>\n Freely soluble in water and in methanol, sparingly soluble in methylene chloride, slightly soluble in acetonitrile.<\/p>\n IDENTIFICATION<\/p>\n A. Infrared absorption spectrophotometry (2.2.24).<\/p>\n Comparison epinastine hydrochloride CRS.<\/p>\n B. It gives reaction (a) of chlorides (2.3.1).<\/p>\n TESTS<\/p>\n Acidity or alkalinity<\/p>\n Dissolve 1.0 g in carbon dioxide-free water R and dilute to 10 mL with the same solvent. Add 0.1 mL of methyl red mixed solution R and 0.25 mL of 0.01 M sodium hydroxide. The solution is green. Add 0.5 mL of 0.01 M hydrochloric acid. The solution is reddish-violet.<\/p>\n Related substances<\/p>\n Liquid chromatography (2.2.29).<\/p>\n Buffer solution pH 4.4 Dissolve 3.8 g of sodium pentanesulfonate monohydrate R and 4.0 g of potassium dihydrogen phosphate R in 900 mL of water for chromatography R, adjust to pH 4.4 with phosphoric acid R and dilute to 1000 mL with water for chromatography R.<\/p>\n Solvent mixture Mobile phase B, mobile phase A (25:75 V\/V).<\/p>\n Test solution Dissolve 50.0 mg of the substance to be examined in 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 5 mg of epinastine for system suitability A CRS (containing impurity A) in 10 mL of the solvent mixture.<\/p>\n Column:<\/p>\n \u2014 size: l = 0.10 m, \u00d8 = 3.0 mm;<\/p>\n \u2014 stationary phase: base-deactivated end-capped octadecylsilyl silica gel for chromatography R (3 \u03bcm);<\/p>\n \u2014 temperature: 50 \u00b0C.<\/p>\n Mobile phase :<\/p>\n \u2014 mobile phase A: methanol R1, buffer solution pH 4.4 (15:85 V\/V);<\/p>\n \u2014 mobile phase B: methanol R1, acetonitrile for chromatography R (15:85 V\/V);<\/p>\n Flow rate 1.4 mL\/min.<\/p>\n Detection: Spectrophotometer at 220 nm.<\/p>\n Injection 10 \u03bcL.<\/p>\n Identification of impurities: Use the chromatogram supplied with epinastine for system suitability A CRS and the chromatogram obtained with reference solution (b) to identify the peak due to impurity A.<\/p>\n Relative retention: With reference to epinastine (retention time = about 4 min): impurity A = about 1.2. \u2014 peak-to-valley ratio: minimum 2.0, where Hp = height above the baseline of the peak due to impurity A and Hv = height above the baseline of the lowest point of the curve separating this peak from the peak due to epinastine.<\/p>\n Calculation of percentage contents:<\/p>\n \u2014 for each impurity, use the concentration of epinastine hydrochloride in reference solution (a).<\/p>\n Limits:<\/p>\n \u2014 impurity A: maximum 0.15 per cent;<\/p>\n \u2014 unspecified impurities: for each impurity, maximum 0.10 per cent;<\/p>\n \u2014 total: maximum 0.7 per cent;<\/p>\n \u2014 reporting threshold: 0.05 per cent.<\/p>\n Loss on drying (2.2.32)<\/p>\n Maximum 1.0 per cent, determined on 1.000 g by drying in an oven at 105 \u00b0C.<\/p>\n Sulfated ash (2.4.14)<\/p>\n Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n ASSAY<\/p>\n Dissolve 0.200 g in 100 mL of a mixture of 1 volume of anhydrous acetic acid R and 2 volumes of acetic anhydride R.<\/p>\n Titrate with 0.1 M perchloric acid, determining the end-point potentiometrically (2.2.20).<\/p>\n 1 mL of 0.1 M perchloric acid is equivalent to 28.58 mg of. C16<\/sub>H16<\/sub>ClN3<\/sub>.<\/p>\n STORAGE<\/p>\n In an airtight container.<\/p>\n IMPURITIES<\/p>\n Specified impurities A.<\/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.<\/p>\n A. 9H-dibenzo[c,f]imidazo[1,5-a]azepin-3-amine,<\/p>\n B. (13bRS)-7-bromo-9,13b-dihydro-1H-dibenzo[c,f]imidazo[1,5-a]azepin-3-amine.<\/p>\n","protected":false},"excerpt":{"rendered":" (Ph. Eur. monograph 2411) C16H16ClN3\u00a0 \u00a0285.8\u00a0 \u00a0108929-04-0 Action and use Antihistamine. DEFINITION (13bRS)-9,13b-Dihydro-1H-dibenzo[c,f]imidazo[1,5-a]azepin-3-amine hydrochloride. Content 99.0 per cent to 101.0 per cent (dried substance). CHARACTERS Appearance White or almost white, hygroscopic, crystalline powder. Solubility Freely soluble in water and in methanol, sparingly soluble in methylene chloride, slightly soluble in acetonitrile. IDENTIFICATION A. Infrared absorption spectrophotometry…<\/p>\n","protected":false},"author":3,"featured_media":10635,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-10623","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-volumes-1-2"],"acf":[],"_links":{"self":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/10623","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\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=10623"}],"version-history":[{"count":3,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/10623\/revisions"}],"predecessor-version":[{"id":10641,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/10623\/revisions\/10641"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/10635"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=10623"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=10623"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=10623"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}DEFINITION<\/h2>\n
Content<\/h3>\n
CHARACTERS<\/h2>\n
Appearance<\/h3>\n
\n\n
\n Time
\n(min)<\/td>\nMobile phase A
\n(per cent V\/V)<\/td>\nMobile phase B
\n(per cent V\/V)<\/td>\n<\/tr>\n\n 0 – 4<\/td>\n 80<\/td>\n 10<\/td>\n<\/tr>\n \n 4 – 13<\/td>\n \u00a080 \u2192 30<\/td>\n 20 \u2192 70<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\nSystem suitability Reference solution (b):<\/p>\n![\"Epinastine](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/1-63-300x163.jpg\")
<\/p>\n![\"Epinastine](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/2-62-300x163.jpg\")
<\/p>\n