{"id":13951,"date":"2025-10-14T14:44:49","date_gmt":"2025-10-14T07:44:49","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=13951"},"modified":"2025-10-14T14:44:49","modified_gmt":"2025-10-14T07:44:49","slug":"gemfibrozil","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/gemfibrozil\/","title":{"rendered":"Gemfibrozil"},"content":{"rendered":"

(Ph. Eur. monograph 1694)<\/p>\n

C_{15<\/sub>H_{22<\/sub>O_{3\u00a0<\/sub> \u00a0 \u00a0 \u00a0250.3\u00a0 \u00a0 \u00a0 \u00a025812-30-0<\/p>\n}}}

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

Fibrate; lipid-regulating drug.<\/p>\n

Preparations<\/strong><\/p>\n

Gemfibrozil Capsules<\/p>\n

Gemfibrozil Tablets<\/p>\n

DEFINITION<\/h2>\n
5-(2,5-Dimethylphenoxy)-2,2-dimethylpentanoic acid.<\/p>\n
Content<\/h3>\n
99.0 per cent to 101.0 per cent (anhydrous substance).<\/p>\n
CHARACTERS<\/h2>\n
Appearance<\/h3>\n
White or almost white, waxy, crystalline powder.<\/p>\n
Solubility<\/h3>\n
Practically insoluble in water, very soluble in methylene chloride, freely soluble in anhydrous ethanol and in methanol.<\/p>\n
IDENTIFICATION<\/h2>\n
A. Melting point (2.2.14): 58 \u00b0C to 61 \u00b0C.<\/p>\n
B. Infrared absorption spectrophotometry (2.2.24).<\/p>\n
Comparison: gemfibrozil CRS.<\/p>\n
TESTS<\/h2>\n
Related substances<\/h3>\n
Liquid chromatography (2.2.29).<\/p>\n
Test solution: Dissolve 40.0 mg of the substance to be examined in mobile phase A and dilute to 10.0 mL with mobile phase A.<\/p>\n
Reference solution (a): Dissolve the contents of a vial of gemfibrozil for system suitability CRS (containing impurities C, D and E) in 2.0 mL of acetonitrile R.<\/p>\n
Reference solution (b): Dilute 1.0 mL of the test solution to 100.0 mL with mobile phase A. Dilute 1.0 mL of this solution to 10.0 mL with mobile phase A.<\/p>\n
Reference solution (c): Dissolve 5 mg of 2,5-dimethylphenol R (impurity A) in mobile phase A and dilute to 10.0 mL with mobile phase A.<\/p>\n
Column:<\/p>\n
\u2014 size: l = 0.25 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: dissolve 0.49 g of potassium acetate R in 400 mL of water for chromatography R, adjust to pH 4.0 with phosphoric acid R and add 600 mL of acetonitrile R;<\/p>\n
\u2014 mobile phase B: acetonitrile R;<\/p>\n\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 – 5<\/td>\n 100<\/td>\n 0<\/td>\n<\/tr>\n
5 – 20<\/td>\n 100 \u2192 0<\/td>\n 0 \u2192 100<\/td>\n<\/tr>\n
20 – 25<\/td>\n 0<\/td>\n 100<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
Flow rate: 1.5 mL\/min.<\/p>\n
Detection: Spectrophotometer at 276 nm.<\/p>\n
Injection: 20 \u03bcL.<\/p>\n
Identification of impurities: Use the chromatogram supplied with gemfibrozil for system suitability CRS and the chromatogram obtained with reference solution (a) to identify the peaks due to impurities C, D and E; use the chromatogram obtained with reference solution (c) to identify the peak due to impurity A.<\/p>\n
Relative retention: With reference to gemfibrozil (retention time = about 7 min): impurity A = about 0.4; impurity C = about 1.3; impurity D = about 1.5; impurity E = about 1.7; impurity I = about 2.0; impurity H = about 2.9.<\/p>\n
System suitability: Reference solution (a):<\/p>\n
\u2014 resolution: minimum 6.0 between the peaks due to gemfibrozil and impurity C, and minimum 2.0 between the peaks due to impurities D and E.<\/p>\n
Limits:<\/p>\n
\u2014 correction factors: for the calculation of content multiply the peak areas of the following impurities by the corresponding correction factor: impurity A = 0.5; impurity D = 1.8; impurity E = 0.2; impurity H = 0.6;<\/p>\n
\u2014 impurities E, I: for each impurity, not more than twice the area of the principal peak in the chromatogram obtained with reference solution (b) (0.2 per cent);<\/p>\n
\u2014 impurities A, D, H: for each impurity, not more than the area of the principal peak in the chromatogram obtained with reference solution (b) (0.1 per cent);<\/p>\n
\u2014 unspecified impurities: for each impurity, not more than the area of the principal peak in the chromatogram obtained with reference solution (b) (0.10 per cent);<\/p>\n
\u2014 total: not more than 5 times the area of the principal peak in the chromatogram obtained with reference solution (b) (0.5 per cent);<\/p>\n
\u2014 disregard limit: 0.5 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)<\/h4>\n
Maximum 0.25 per cent, determined on 2.000 g.<\/p>\n
Sulfated ash (2.4.14)<\/h4>\n
Maximum 0.1 per cent, determined on 2.0 g. Allow to stand for 1 h after the first moistening before heating.<\/p>\n
ASSAY<\/h2>\n
Dissolve 0.200 g in 40 mL of methanol R. Add 10 mL of water R and 1 mL of 0.1 M hydrochloric acid. Carry out a potentiometric titration (2.2.20) using 0.1 M sodium hydroxide. Read the volume added between the 2 points of inflexion.<\/p>\n
1 mL of 0.1 M sodium hydroxide is equivalent to 25.03 mg of C_{15<\/sub>H_{22<\/sub>O_{3<\/sub>.<\/p>\n}}}
STORAGE<\/h2>\n
Protected from light.<\/p>\n
IMPURITIES<\/h2>\n
Specified impurities A, D, E, H, I.<\/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, F, G.<\/p>\n
<\/p>\n
A. 2,5-dimethylphenol (p-xylenol),<\/p>\n
B. 5-(2,5-dimethylphenoxy)-2,2-dimethylpentanamide,<\/p>\n
C. 2-[3-(2-ethoxyethoxy)propoxy]-1,4-dimethylbenzene,<\/p>\n
D. 5-[3,6-dimethyl-2-(prop-1-en-1-yl)phenoxy]-2,2-dimethylpentanoic acid,<\/p>\n
E. 5-[2,5-dimethyl-4-(prop-1-en-1-yl)phenoxy]-2,2-dimethylpentanoic acid,<\/p>\n
F. 1,4-dimethyl-2-(4-phenylbutoxy)benzene,<\/p>\n
G. 1,4-dimethyl-2-(prop-2-en-1-yloxy)benzene,<\/p>\n
H. 1,1\u2032-[propane-1,3-diylbis(oxy)]bis(2,5-dimethylbenzene),<\/p>\n
I. methyl 5-(2,5-dimethylphenoxy)-2,2-dimethylpentanoate.<\/p>\n","protected":false},"excerpt":{"rendered":"
(Ph. Eur. monograph 1694) C15H22O3\u00a0 \u00a0 \u00a0 \u00a0250.3\u00a0 \u00a0 \u00a0 \u00a025812-30-0 Action and use Fibrate; lipid-regulating drug. Preparations Gemfibrozil Capsules Gemfibrozil Tablets DEFINITION 5-(2,5-Dimethylphenoxy)-2,2-dimethylpentanoic acid. Content 99.0 per cent to 101.0 per cent (anhydrous substance). CHARACTERS Appearance White or almost white, waxy, crystalline powder. Solubility Practically insoluble in water, very soluble in methylene chloride, freely…<\/p>\n","protected":false},"author":2,"featured_media":13983,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-13951","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\/13951","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=13951"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/13951\/revisions"}],"predecessor-version":[{"id":13995,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/13951\/revisions\/13995"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/13983"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=13951"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=13951"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=13951"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

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 – 5<\/td>\n	100<\/td>\n	0<\/td>\n<\/tr>\n
5 – 20<\/td>\n	100 \u2192 0<\/td>\n	0 \u2192 100<\/td>\n<\/tr>\n
20 – 25<\/td>\n	0<\/td>\n	100<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Flow rate: 1.5 mL\/min.<\/p>\n Detection: Spectrophotometer at 276 nm.<\/p>\n Injection: 20 \u03bcL.<\/p>\n Identification of impurities: Use the chromatogram supplied with gemfibrozil for system suitability CRS and the chromatogram obtained with reference solution (a) to identify the peaks due to impurities C, D and E; use the chromatogram obtained with reference solution (c) to identify the peak due to impurity A.<\/p>\n Relative retention: With reference to gemfibrozil (retention time = about 7 min): impurity A = about 0.4; impurity C = about 1.3; impurity D = about 1.5; impurity E = about 1.7; impurity I = about 2.0; impurity H = about 2.9.<\/p>\n System suitability: Reference solution (a):<\/p>\n \u2014 resolution: minimum 6.0 between the peaks due to gemfibrozil and impurity C, and minimum 2.0 between the peaks due to impurities D and E.<\/p>\n Limits:<\/p>\n \u2014 correction factors: for the calculation of content multiply the peak areas of the following impurities by the corresponding correction factor: impurity A = 0.5; impurity D = 1.8; impurity E = 0.2; impurity H = 0.6;<\/p>\n \u2014 impurities E, I: for each impurity, not more than twice the area of the principal peak in the chromatogram obtained with reference solution (b) (0.2 per cent);<\/p>\n \u2014 impurities A, D, H: for each impurity, not more than the area of the principal peak in the chromatogram obtained with reference solution (b) (0.1 per cent);<\/p>\n \u2014 unspecified impurities: for each impurity, not more than the area of the principal peak in the chromatogram obtained with reference solution (b) (0.10 per cent);<\/p>\n \u2014 total: not more than 5 times the area of the principal peak in the chromatogram obtained with reference solution (b) (0.5 per cent);<\/p>\n \u2014 disregard limit: 0.5 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)<\/h4>\n Maximum 0.25 per cent, determined on 2.000 g.<\/p>\n Sulfated ash (2.4.14)<\/h4>\n Maximum 0.1 per cent, determined on 2.0 g. Allow to stand for 1 h after the first moistening before heating.<\/p>\n ASSAY<\/h2>\n Dissolve 0.200 g in 40 mL of methanol R. Add 10 mL of water R and 1 mL of 0.1 M hydrochloric acid. Carry out a potentiometric titration (2.2.20) using 0.1 M sodium hydroxide. Read the volume added between the 2 points of inflexion.<\/p>\n 1 mL of 0.1 M sodium hydroxide is equivalent to 25.03 mg of C_{15<\/sub>H_{22<\/sub>O_{3<\/sub>.<\/p>\n}}} STORAGE<\/h2>\n Protected from light.<\/p>\n IMPURITIES<\/h2>\n Specified impurities A, D, E, H, I.<\/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, F, G.<\/p>\n <\/p>\n A. 2,5-dimethylphenol (p-xylenol),<\/p>\n B. 5-(2,5-dimethylphenoxy)-2,2-dimethylpentanamide,<\/p>\n C. 2-[3-(2-ethoxyethoxy)propoxy]-1,4-dimethylbenzene,<\/p>\n D. 5-[3,6-dimethyl-2-(prop-1-en-1-yl)phenoxy]-2,2-dimethylpentanoic acid,<\/p>\n E. 5-[2,5-dimethyl-4-(prop-1-en-1-yl)phenoxy]-2,2-dimethylpentanoic acid,<\/p>\n F. 1,4-dimethyl-2-(4-phenylbutoxy)benzene,<\/p>\n G. 1,4-dimethyl-2-(prop-2-en-1-yloxy)benzene,<\/p>\n H. 1,1\u2032-[propane-1,3-diylbis(oxy)]bis(2,5-dimethylbenzene),<\/p>\n I. methyl 5-(2,5-dimethylphenoxy)-2,2-dimethylpentanoate.<\/p>\n","protected":false},"excerpt":{"rendered":" (Ph. Eur. monograph 1694) C15H22O3\u00a0 \u00a0 \u00a0 \u00a0250.3\u00a0 \u00a0 \u00a0 \u00a025812-30-0 Action and use Fibrate; lipid-regulating drug. Preparations Gemfibrozil Capsules Gemfibrozil Tablets DEFINITION 5-(2,5-Dimethylphenoxy)-2,2-dimethylpentanoic acid. Content 99.0 per cent to 101.0 per cent (anhydrous substance). CHARACTERS Appearance White or almost white, waxy, crystalline powder. Solubility Practically insoluble in water, very soluble in methylene chloride, freely…<\/p>\n","protected":false},"author":2,"featured_media":13983,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-13951","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\/13951","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=13951"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/13951\/revisions"}],"predecessor-version":[{"id":13995,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/13951\/revisions\/13995"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/13983"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=13951"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=13951"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=13951"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

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

CHARACTERS<\/h2>\n

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

Solubility<\/h3>\nPractically insoluble in water, very soluble in methylene chloride, freely soluble in anhydrous ethanol and in methanol.<\/p>\n

IDENTIFICATION<\/h2>\nA. Melting point (2.2.14): 58 \u00b0C to 61 \u00b0C.<\/p>\nB. Infrared absorption spectrophotometry (2.2.24).<\/p>\nComparison: gemfibrozil CRS.<\/p>\n

TESTS<\/h2>\n

Water (2.5.12)<\/h4>\nMaximum 0.25 per cent, determined on 2.000 g.<\/p>\n

Sulfated ash (2.4.14)<\/h4>\nMaximum 0.1 per cent, determined on 2.0 g. Allow to stand for 1 h after the first moistening before heating.<\/p>\n

STORAGE<\/h2>\nProtected from light.<\/p>\n

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

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

Solubility<\/h3>\n
Practically insoluble in water, very soluble in methylene chloride, freely soluble in anhydrous ethanol and in methanol.<\/p>\n

IDENTIFICATION<\/h2>\n
A. Melting point (2.2.14): 58 \u00b0C to 61 \u00b0C.<\/p>\n
B. Infrared absorption spectrophotometry (2.2.24).<\/p>\n
Comparison: gemfibrozil CRS.<\/p>\n

Water (2.5.12)<\/h4>\n
Maximum 0.25 per cent, determined on 2.000 g.<\/p>\n

Sulfated ash (2.4.14)<\/h4>\n
Maximum 0.1 per cent, determined on 2.0 g. Allow to stand for 1 h after the first moistening before heating.<\/p>\n

STORAGE<\/h2>\n
Protected from light.<\/p>\n