Edition: BP 2025 (Ph. Eur. 11.6 update)<\/p>\n
Action and use<\/strong><\/p>\n Rifamycin antimycobacterial drug.<\/p>\n (9S,12E,14S,15R,16S,17R,18R,19R,20S,21S,22E,24Z)-6,18,20-Trihydroxy-14-methoxy-7,9,15,17,19,21,25-heptamethyl-1\u2032-(2-methylpropyl)-5,10,26-trioxo-3,5,9,10-tetrahydrospiro[9,4-(epoxypentadeca[1,11,13]trienimino)-2H- furo[2\u2032,3\u2032:7,8]naphtho[1,2-d]imidazole-2,4\u2032-piperidine]-16-yl acetate.<\/p>\n Semi-synthetic product derived from a fermentation product.<\/p>\n Content<\/strong><\/p>\n 96.0 per cent to 102.0 per cent (anhydrous substance).<\/p>\n Reddish-violet amorphous powder.<\/p>\n Slightly soluble in water, soluble in methanol, slightly soluble in ethanol (96 per cent).<\/p>\n A. Infrared absorption spectrophotometry (2.2.24).<\/p>\n Preparation\u00a0 Discs.<\/p>\n Comparison\u00a0 rifabutin CRS.<\/p>\n B. Examine the chromatograms obtained in the test for related substances.<\/p>\n Results The principal peak in the chromatogram obtained with the test solution is similar in retention time and size to the principal peak in the chromatogram obtained with reference solution (a).<\/p>\n Thin-layer chromatography (2.2.27).<\/p>\n Test solution\u00a0 Dissolve 0.100 g of the substance to be examined in a mixture of equal volumes of methanol R and methylene chloride R and dilute to 10 mL with the same mixture of solvents.<\/p>\n Reference solution Dissolve 10 mg of rifabutin impurity A CRS in a mixture of equal volumes of methanol R and methylene chloride R and dilute to 10 mL with the same mixture of solvents. Dilute 3 mL of the solution to 100 mL with a mixture of equal volumes of methanol R and methylene chloride R.<\/p>\n Plate\u00a0 TLC silica gel F254 plate R.<\/p>\n Mobile phase acetone R, light petroleum R (23:77 V\/V). Application 10 \u00b5L.<\/p>\n Development\u00a0 Over 2\/3 of the plate.<\/p>\n Drying\u00a0 In air.<\/p>\n Detection Expose the plate to iodine vapour for about 5 min, then spray with potassium iodide and starch solution R and allow to stand for 5 min.<\/p>\n Limit:<\/p>\n \u2014 impurity A: any spot corresponding to impurity A is not more intense than the spot in the chromatogram obtained with the reference solution (0.3 per cent).<\/p>\n Liquid chromatography (2.2.29).<\/p>\n Test solution Dissolve 50.0 mg of the substance to be examined in the mobile phase and dilute to 50.0 mL with the mobile phase.<\/p>\n Reference solution (a) Dissolve 50.0 mg of rifabutin CRS in the mobile phase and dilute to 50.0 mL with the mobile phase.<\/p>\n Reference solution (b)\u00a0 Dilute 1.0 mL of reference solution (a) to 100.0 mL with the mobile phase.<\/p>\n Reference solution (c) Dissolve about 10 mg of rifabutin CRS in 2 mL of methanol R, add 1 mL of dilute sodium hydroxide solution R and allow to stand for about 4 min. Add 1 mL of dilute hydrochloric acid R and dilute to 50 mL with the mobile phase.<\/p>\n Column:<\/p>\n \u2014 size: l = 0.110 m, \u00d8 = 4.6 mm,<\/p>\n \u2014 stationary phase: octylsilyl silica gel for chromatography R (5 \u00b5m).<\/p>\n Mobile phase Mix equal volumes of acetonitrile R and a 13.6 g\/L solution of potassium dihydrogen phosphate R adjusted to pH 6.5 with dilute sodium hydroxide solution R.<\/p>\n Flow rate\u00a0 1 mL\/min.<\/p>\n Detection\u00a0 Spectrophotometer at 254 nm.<\/p>\n Injection\u00a0 20 \u00b5L.<\/p>\n Run time\u00a0 2.5 times the retention time of rifabutin.<\/p>\n Relative retention With reference to rifabutin (retention time = about 9 min): impurity E = about 0.5; impurity B = about 0.6; impurity D = about 0.9; impurity C = about 1.3.<\/p>\n System suitability\u00a0 Reference solution (c):<\/p>\n \u2014 resolution: minimum 2.0 between the second peak of the 3 peaks due to degradation products and the peak due to rifabutin.<\/p>\n Limits:<\/p>\n \u2014 any impurity: not more than the area of the principal peak in the chromatogram obtained with reference solution (b) (1.0 per cent); not more than 1 such peak has an area greater than half the area of the principal peak in the chromatogram obtained with reference solution (b) (0.5 per cent),<\/p>\n \u2014 total: not more than 3 times the area of the principal peak in the chromatogram obtained with reference solution (b) (3.0 per cent),<\/p>\n \u2014 disregard limit: 0.05 times the area of the principal peak in the chromatogram obtained with reference solution (b) (0.05 per cent).<\/p>\n Water (2.5.12)<\/strong><\/p>\n Maximum 2.5 per cent, determined on 0.200 g.<\/p>\n Sulfated ash (2.4.14)<\/strong><\/p>\n Maximum 0.3 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.<\/p>\n Injection Test solution and reference solution (a). Calculate the percentage content of ribabutin.<\/p>\n A. 1-(2-methylpropyl)piperidin-4-one,<\/p>\n B. 3-aminorifamycin S,<\/p>\n C. 21,31-didehydrorifabutin,<\/p>\n D. 3-amino-4-imidorifamycin S,<\/p>\n E. 16-deacetylrifabutin.<\/p>\n","protected":false},"excerpt":{"rendered":" Edition: BP 2025 (Ph. Eur. 11.6 update) Action and use Rifamycin antimycobacterial drug. DEFINITION (9S,12E,14S,15R,16S,17R,18R,19R,20S,21S,22E,24Z)-6,18,20-Trihydroxy-14-methoxy-7,9,15,17,19,21,25-heptamethyl-1\u2032-(2-methylpropyl)-5,10,26-trioxo-3,5,9,10-tetrahydrospiro[9,4-(epoxypentadeca[1,11,13]trienimino)-2H- furo[2\u2032,3\u2032:7,8]naphtho[1,2-d]imidazole-2,4\u2032-piperidine]-16-yl acetate. Semi-synthetic product derived from a fermentation product. Content 96.0 per cent to 102.0 per cent (anhydrous substance). CHARACTERS Appearance Reddish-violet amorphous powder. Solubility Slightly soluble in water, soluble in methanol, slightly soluble in ethanol (96 per cent). IDENTIFICATION…<\/p>\n","protected":false},"author":5,"featured_media":30069,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-30068","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\/30068","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=30068"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/30068\/revisions"}],"predecessor-version":[{"id":30072,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/30068\/revisions\/30072"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/30069"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=30068"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=30068"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=30068"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}DEFINITION<\/h2>\n
CHARACTERS<\/h2>\n
Appearance<\/h3>\n
Solubility<\/h3>\n
IDENTIFICATION<\/h2>\n
TESTS<\/h2>\n
Impurity A<\/h3>\n
Related substances<\/h3>\n
ASSAY<\/h2>\n
IMPURITIES<\/h2>\n