{"id":10212,"date":"2025-10-07T14:50:22","date_gmt":"2025-10-07T07:50:22","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=10212"},"modified":"2025-10-07T14:50:22","modified_gmt":"2025-10-07T07:50:22","slug":"dexamethasone-isonicotinate","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/dexamethasone-isonicotinate\/","title":{"rendered":"Dexamethasone Isonicotinate"},"content":{"rendered":"

(Ph. Eur. monograph 2237)<\/p>\n

C_{28<\/sub>H_{32<\/sub>FNO_{6<\/sub>\u00a0 \u00a0 \u00a0 \u00a0497.6\u00a0 \u00a0 \u00a0 \u00a02265-64-7<\/p>\n}}}

Action and use<\/strong><\/p>\n

Glucocorticoid.<\/p>\n

DEFINITION<\/h2>\n
9-Fluoro-11\u03b2,17-dihydroxy-16\u03b1-methyl-3,20-dioxopregna-1,4-dien-21-yl pyridine-4-carboxylate.<\/p>\n
Content<\/h3>\n
99.0 per cent to 101.0 per cent (dried substance).<\/p>\n
CHARACTERS<\/h2>\n
Appearance<\/h3>\n
White or almost white crystalline powder.<\/p>\n
Solubility<\/h3>\n
Practically insoluble in water, slightly soluble in anhydrous ethanol and in acetone.<\/p>\n
IDENTIFICATION<\/h2>\n
Infrared absorption spectrophotometry (2.2.24).<\/p>\n
Comparison: dexamethasone isonicotinate CRS.<\/p>\n
TESTS<\/h2>\n
Specific optical rotation (2.2.7)<\/h3>\n
+ 142 to + 146 (dried substance).<\/p>\n
Suspend 0.200 g in 4.0 mL of ethyl acetate R and dilute to 20.0 mL with ethanol (96 per cent) R. Treat in an ultrasonic ba until a clear solution is obtained.<\/p>\n
Related substances<\/h3>\n
Liquid chromatography (2.2.29). Prepare solutions immediately before use.<\/p>\n
Test solution: Suspend 50.0 mg in 7 mL of acetonitrile R and dilute to 10.0 mL with water R. Treat in an ultrasonic bath until a clear solution is obtained.<\/p>\n
Reference solution (a): Suspend 5.0 mg of dexamethasone CRS (impurity A) and 5.0 mg of dexamethasone acetate CR (impurity B) in 70 mL of acetonitrile R, add 1.0 mL of the test solution and dilute to 100.0 mL with water R. Treat in an ultrasonic bath until a clear solution is obtained.<\/p>\n
Reference solution (b): Dilute 1.0 mL of reference solution (a) to 10.0 mL with water R.<\/p>\n
Reference solution (c): Suspend 5 mg of dexamethasone isonicotinate for impurity C identification CRS in 0.7 mL of acetonitrile R and dilute to 1 mL with water R. Treat in an ultrasonic bath until a clear solution is obtained.<\/p>\n
Column:<\/p>\n
\u2014 size: l = 0.125 m, \u00d8 = 4.0 mm,<\/p>\n
\u2014 stationary phase: end-capped octadecylsilyl silica gel for chromatography R (5 \u03bcm).<\/p>\n
Mobile phase:<\/p>\n
\u2014 mobile phase A: water for chromatography R,<\/p>\n
\u2014 mobile phase B: acetonitrile for chromatography R,<\/p>\n\n\n\n\n\n
Time<\/strong>
\n(min)<\/strong><\/td>\n Mobile phase A<\/strong>
\n(per cent V\/V)<\/strong><\/td>\n Mobile phase B<\/strong>
\n(per cent V\/V)<\/strong><\/td>\n<\/tr>\n
0 – 2<\/td>\n 68<\/td>\n 32<\/td>\n<\/tr>\n
2 – 20<\/td>\n 68 \u2192 50<\/td>\n 32 \u2192 50<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
Flow rate: 1.2 mL\/min.<\/p>\n
Detection: Spectrophotometer at 240 nm.<\/p>\n
Injection: 10 \u03bcL.<\/p>\n
Identification of impurities: Use the chromatogram obtained with reference solution (a) to identify the peaks due to impurities A and B; use the chromatogram supplied with dexamethasone isonicotinate for impurity C identification CRS an the chromatogram obtained with reference solution (c) to identify the peak due to impurity C.<\/p>\n
Relative retention: With reference to dexamethasone isonicotinate (retention time = about 12 min): impurity A = about 0.4 impurity C = about 0.6; impurity B = about 0.8.<\/p>\n
System suitability: Reference solution (a):<\/p>\n
\u2014 resolution: minimum 5.0 between the peaks due to impurity B and dexamethasone isonicotinate.<\/p>\n
Limits:<\/p>\n
\u2014 impurity A: not more than 5 times the area of the corresponding peak in the chromatogram obtained with reference solution (b) (0.5 per cent),<\/p>\n
\u2014 impurity B: not more than 3 times the area of the corresponding peak in the chromatogram obtained with reference solution (b) (0.3 per cent),<\/p>\n
\u2014 impurity C: not more than 3 times the area of the peak due to dexamethasone isonicotinate in the chromatogram obtained with reference solution (b) (0.3 per cent),<\/p>\n
\u2014 unspecified impurities: for each impurity, not more than the area of the peak due to dexamethasone isonicotinate i the chromatogram obtained with reference solution (b) (0.10 per cent),<\/p>\n
\u2014 total: not more than 8 times the area of the peak due to dexamethasone isonicotinate in the chromatogram obtained with reference solution (b) (0.8 per cent),<\/p>\n
\u2014 disregard limit: 0.5 times the area of the peak due to dexamethasone isonicotinate in the chromatogram obtained with reference solution (b) (0.05 per cent).<\/p>\n
Loss on drying (2.2.32)<\/h4>\n
Maximum 1.0 per cent, determined on 1.000 g by drying in vacuo at 105 \u00b0C at a pressure not exceeding 0.1 kPa for 4 h.<\/p>\n
ASSAY<\/h2>\n
Dissolve 0.400 g in a mixture of 5 mL of anhydrous formic acid R and 50 mL of glacial acetic acid R. 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 49.76 mg of 6C_{28<\/sub>H_{32<\/sub>FNO_{6<\/sub>.<\/p>\n}}}
IMPURITIES<\/h2>\n
Specified impurities A, B, C.<\/p>\n
$\"Dexamethasone$ <\/p>\n
A. 9-fluoro-11\u03b2,17,21-trihydroxy-16\u03b1-methylpregna-1,4-diene-3,20-dione (dexamethasone),<\/p>\n
$\"Dexamethasone$ <\/p>\n
B. 9-fluoro-11\u03b2,17-dihydroxy-16\u03b1-methyl-3,20-dioxopregna-1,4-dien-21-yl acetate (dexamethasone acetate),<\/p>\n
$\"Dexamethasone$ <\/p>\n
C. 9-fluoro-11\u03b2,17-dihydroxy-16\u03b1-methylpregna-1,4-diene-3,20-dione (21-deoxydexamethasone).<\/p>\n","protected":false},"excerpt":{"rendered":"
(Ph. Eur. monograph 2237) C28H32FNO6\u00a0 \u00a0 \u00a0 \u00a0497.6\u00a0 \u00a0 \u00a0 \u00a02265-64-7 Action and use Glucocorticoid. DEFINITION 9-Fluoro-11\u03b2,17-dihydroxy-16\u03b1-methyl-3,20-dioxopregna-1,4-dien-21-yl pyridine-4-carboxylate. Content 99.0 per cent to 101.0 per cent (dried substance). CHARACTERS Appearance White or almost white crystalline powder. Solubility Practically insoluble in water, slightly soluble in anhydrous ethanol and in acetone. IDENTIFICATION Infrared absorption spectrophotometry (2.2.24). Comparison:…<\/p>\n","protected":false},"author":2,"featured_media":10234,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174,1],"tags":[],"class_list":["post-10212","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-medicinal-substances","category-volumes-1-2"],"acf":[],"_links":{"self":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/10212","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\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=10212"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/10212\/revisions"}],"predecessor-version":[{"id":10240,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/10212\/revisions\/10240"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/10234"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=10212"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=10212"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=10212"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

Content<\/h3>\n99.0 per cent to 101.0 per cent (dried substance).<\/p>\n

CHARACTERS<\/h2>\n

Appearance<\/h3>\nWhite or almost white crystalline powder.<\/p>\n

Solubility<\/h3>\nPractically insoluble in water, slightly soluble in anhydrous ethanol and in acetone.<\/p>\n

IDENTIFICATION<\/h2>\nInfrared absorption spectrophotometry (2.2.24).<\/p>\nComparison: dexamethasone isonicotinate CRS.<\/p>\n

TESTS<\/h2>\n

Specific optical rotation (2.2.7)<\/h3>\n+ 142 to + 146 (dried substance).<\/p>\nSuspend 0.200 g in 4.0 mL of ethyl acetate R and dilute to 20.0 mL with ethanol (96 per cent) R. Treat in an ultrasonic ba until a clear solution is obtained.<\/p>\n

Loss on drying (2.2.32)<\/h4>\nMaximum 1.0 per cent, determined on 1.000 g by drying in vacuo at 105 \u00b0C at a pressure not exceeding 0.1 kPa for 4 h.<\/p>\n

Content<\/h3>\n
99.0 per cent to 101.0 per cent (dried substance).<\/p>\n

Appearance<\/h3>\n
White or almost white crystalline powder.<\/p>\n

Solubility<\/h3>\n
Practically insoluble in water, slightly soluble in anhydrous ethanol and in acetone.<\/p>\n

IDENTIFICATION<\/h2>\n
Infrared absorption spectrophotometry (2.2.24).<\/p>\n
Comparison: dexamethasone isonicotinate CRS.<\/p>\n

Specific optical rotation (2.2.7)<\/h3>\n
+ 142 to + 146 (dried substance).<\/p>\n
Suspend 0.200 g in 4.0 mL of ethyl acetate R and dilute to 20.0 mL with ethanol (96 per cent) R. Treat in an ultrasonic ba until a clear solution is obtained.<\/p>\n

Loss on drying (2.2.32)<\/h4>\n
Maximum 1.0 per cent, determined on 1.000 g by drying in vacuo at 105 \u00b0C at a pressure not exceeding 0.1 kPa for 4 h.<\/p>\n