(Ph. Eur. monograph 0954)<\/p>\n
![\"Temazepam\"](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/Temazepam.jpg\")
<\/p>\n
C16<\/sub>H13<\/sub>ClN2<\/sub>O2\u00a0 \u00a0\u00a0<\/sub> 300.7\u00a0 \u00a0 \u00a0846-50-4<\/p>\n Action and use<\/strong><\/p>\n Benzodiazepine.<\/p>\n Preparations<\/strong><\/p>\n Temazepam Oral Solution<\/p>\n Temazepam Tablets<\/p>\n Ph Eur<\/p>\n (3RS)-7-Chloro-3-hydroxy-1-methyl-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one.<\/p>\n Content<\/strong><\/p>\n 98.0 per cent to 102.0 per cent (dried substance).<\/p>\n Appearance<\/strong><\/p>\n White or almost white, crystalline powder.<\/p>\n Solubility<\/strong><\/p>\n Practically insoluble in water, freely soluble in methylene chloride, sparingly soluble in ethanol (96 per cent).<\/p>\n Infrared absorption spectrophotometry (2.2.24).<\/p>\n Comparison: temazepam for ID and assay CRS.<\/p>\n Related substance<\/p>\n Liquid chromatography (2.2.29).<\/p>\n Solvent mixture: acetonitrile R, mobile phase A (30:70 V\/V).<\/p>\n Test solution (a): Dissolve 20.0 mg of the substance to be examined in 6 mL of acetonitrile R and dilute to 20.0 mL with a 3.9 g\/L solution of ammonium acetate R.<\/p>\n Test solution (b): Dilute 1.0 mL of test solution (a) to 10.0 mL with the solvent mixture.<\/p>\n Reference solution (a): Dissolve the contents of a vial of temazepam for system suitability CRS (containing impurities A, B, E and G) in 300 \u03bcL of acetonitrile R; then add 700 \u03bcL of mobile phase A.<\/p>\n Reference solution (b): Dilute 1.0 mL of test solution (a) 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 (c): Dissolve 20.0 mg of temazepam for ID and assay CRS in 6 mL of acetonitrile R and dilute to 20.0 mL with a 3.9 g\/L solution of ammonium acetate R. Dilute 1.0 mL of the solution to 10.0 mL with the solvent mixture.<\/p>\n Column:<\/p>\n \u2014 size: l = 0.075 m, \u00d8 = 4.6 mm;<\/p>\n \u2014 stationary phase: end-capped solid core octadecylsilyl silica gel for chromatography R (2.6 \u03bcm).<\/p>\n Mobile phase:<\/p>\n \u2014 mobile phase A: 3.9 g\/L solution of ammonium acetate R;<\/p>\n \u2014 mobile phase B: acetonitrile R.<\/p>\n Flow rate: 1.0 mL\/min.<\/p>\n Detection: Spectrophotometer at 254 nm.<\/p>\n Injection: 20 \u03bcL of test solution (a) and reference solutions (a) and (b).<\/p>\n Identification of impurities: Use the chromatogram supplied with temazepam for system suitability CRS and the chromatogram obtained with reference solution (a) to identify the peaks due to impurities A, B, E and G.<\/p>\n Relative retention:<\/p>\n With reference to temazepam (retention time = about 7 min):<\/p>\n \u2014 impurity B = about 0.57;<\/p>\n \u2014 impurity E = about 0.62;<\/p>\n \u2014 impurity G = about 1.2;<\/p>\n \u2014 impurity A = about 3.<\/p>\n System suitability: 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 G and Hv = height above the baseline of the lowest point of the curve separating this peak from the peak due to temazepam;<\/p>\n \u2014 resolution: minimum 2.0 between the peaks due to impurities B and E.<\/p>\n Calculation of percentage contents:<\/p>\n \u2014 correction factor: for the calculation of content, multiply the peak area of impurity E by 0.7;<\/p>\n \u2014 for each impurity, use the concentration of temazepam in reference solution (b).<\/p>\n Limits:<\/p>\n \u2014 impurity E: maximum 0.2 per cent;<\/p>\n \u2014 impurity A: maximum 0.05 per cent;<\/p>\n \u2014 unspecified impurities: for each impurity, maximum 0.10 per cent;<\/p>\n \u2014 total: maximum 0.5 per cent;<\/p>\n \u2014 reporting threshold: 0.05 per cent; do not disregard the peak due to impurity A;<\/p>\n \u2014 reporting threshold for impurity A: 0.025 per cent.<\/p>\n Loss on drying (2.2.32):<\/p>\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):<\/p>\n Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n Liquid chromatography (2.2.29) as described in the test for related substances with the following modification. Calculate the percentage content of C16<\/sub>H13<\/sub>ClN2<\/sub>O2\u00a0<\/sub> taking into account the assigned content of temazepam for ID and assay CRS.<\/p>\n Protected from light.<\/p>\n Specified impurities: A, E.<\/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.) A. [5-chloro-2-(methylamino)phenyl](phenyl)methanone,<\/p>\n B. (3RS)-7-chloro-3-hydroxy-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one (oxazepam),<\/p>\n C. (3RS)-7-chloro-1-methyl-2-oxo-5-phenyl-2,3-dihydro-1H-1,4-benzodiazepin-3-yl acetate,<\/p>\n D. (3RS)-7-chloro-3-methoxy-1-methyl-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one,<\/p>\n F. (5RS)-7-chloro-1-methyl-5-phenyl-4,5-dihydro-1H-1,4-benzodiazepine-2,3-dione,<\/p>\n G. (5RS)-7-chloro-1,4-dimethyl-5-phenyl-4,5-dihydro-1H-1,4-benzodiazepine-2,3-dione,<\/p>\n H. 7-chloro-1-methyl-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one (diazepam)<\/p>\n","protected":false},"excerpt":{"rendered":" (Ph. Eur. 11.6 update) General Notices (Ph. Eur. monograph 0954) C16H13ClN2O2\u00a0 \u00a0\u00a0 300.7\u00a0 \u00a0 \u00a0846-50-4 Action and use Benzodiazepine. Preparations Temazepam Oral Solution Temazepam Tablets Ph Eur DEFINITION (3RS)-7-Chloro-3-hydroxy-1-methyl-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one. Content 98.0 per cent to 102.0 per cent (dried substance). CHARACTERS Appearance White or almost white, crystalline powder. Solubility Practically insoluble in water, freely soluble in…<\/p>\n","protected":false},"author":4,"featured_media":28666,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-28634","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\/28634","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\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=28634"}],"version-history":[{"count":3,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/28634\/revisions"}],"predecessor-version":[{"id":28740,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/28634\/revisions\/28740"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/28666"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=28634"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=28634"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=28634"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}DEFINITION<\/h2>\n
CHARACTERS<\/h2>\n
IDENTIFICATION<\/h2>\n
TESTS<\/h2>\n
\n\n
\n Time (min)<\/th>\n Mobile phase A (per cent V\/V)<\/th>\n Mobile phase B (per cent V\/V)<\/th>\n<\/tr>\n \n 0 – 13<\/td>\n 70<\/td>\n 30<\/td>\n<\/tr>\n \n 13 – 25<\/td>\n 70 \u2192 30<\/td>\n 30 \u2192 70<\/td>\n<\/tr>\n \n 25 – 28<\/td>\n 30<\/td>\n 70<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n ASSAY<\/h2>\n
\nInjection: Test solution (b) and reference solution (c).<\/p>\nSTORAGE<\/h2>\n
IMPURITIES<\/h2>\n
\nB, C, D, F, G.<\/p>\n![\"A.](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/A.-5-chloro-2-methylaminophenylphenylmethanone.png\")
<\/p>\n![\"B.](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/B.-3RS-7-chloro-3-hydroxy-5-phenyl-13-dihydro-2H-14-benzodiazepin-2-one-oxazepam.png\")
<\/p>\n![\"C.](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/C.-3RS-7-chloro-1-methyl-2-oxo-5-phenyl-23-dihydro-1H-14-benzodiazepin-3-yl-acetate.png\")
<\/p>\n![\"D.](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/D.-3RS-7-chloro-3-methoxy-1-methyl-5-phenyl-13-dihydro-2H-14-benzodiazepin-2-one.png\")
<\/p>\n![\"F.](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/F.-5RS-7-chloro-1-methyl-5-phenyl-45-dihydro-1H-14-benzodiazepine-23-dione.png\")
<\/p>\n![\"G.](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/G.-5RS-7-chloro-14-dimethyl-5-phenyl-45-dihydro-1H-14-benzodiazepine-23-dione.png\")
<\/p>\n![\"H.](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/11\/H.-7-chloro-1-methyl-5-phenyl-13-dihydro-2H-14-benzodiazepin-2-one-diazepam.png\")
<\/p>\n