Action and use<\/strong><\/p>\n Antiviral (cytomegalovirus).<\/p>\n Preparation<\/strong><\/p>\n Foscarnet Infusion<\/p>\n Trisodium phosphonatoformate hexahydrate.<\/p>\n 98.5 per cent to 101.0 per cent (dried substance).<\/p>\n White or almost white, crystalline powder.<\/p>\n Soluble in water, practically insoluble in ethanol (96 per cent).<\/p>\n A. Infrared absorption spectrophotometry (2.2.24).<\/p>\n Comparison foscarnet sodium hexahydrate CRS.<\/p>\n B. It gives reaction (a) of sodium (2.3.1).<\/p>\n Dissolve 0.5 g in carbon dioxide-free water R and dilute to 25 mL with the same solvent.<\/p>\n Solution S is not more opalescent than reference suspension I (2.2.1) and is colourless (2.2.2, Method II).<\/p>\n 9.0 to 11.0 for solution S.<\/p>\n Gas chromatography (2.2.28).<\/p>\n Test solution: Dissolve 0.250 g of the substance to be examined in 9.0 mL of a 6 g\/L solution of glacial acetic acid R using a magnetic stirrer. Add 1.0 mL of anhydrous ethanol R and mix.<\/p>\n Reference solution: Dissolve 25.0 mg of foscarnet impurity D CRS in anhydrous ethanol R and dilute to 100.0 mL with the same solvent. Dilute 1.0 mL of this solution to 10.0 mL with anhydrous ethanol R.<\/p>\n Column:<\/p>\n \u2014 material: fused silica;<\/p>\n \u2014 size: l = 25 m, \u00d8 = 0.31 mm;<\/p>\n \u2014 stationary phase: phenyl(5)methyl(95)polysiloxane R (film thickness 0.5 \u03bcm).<\/p>\n Carrier gas helium for chromatography R.<\/p>\n Split ratio 1:20.<\/p>\n Temperature:<\/p>\n Detection Flame ionisation.<\/p>\n Injection 3 \u03bcL<\/p>\n Limit:<\/p>\n \u2014 impurity D: not more than the area of the principal peak in the chromatogram obtained with the reference solution (0.1 per cent).<\/p>\n Liquid chromatography (2.2.29).<\/p>\n Test solution: Dissolve 25 mg of the substance to be examined in the mobile phase and dilute to 10.0 mL with the mobile phase.<\/p>\n Reference solution (a): Dilute 1.0 mL of the test solution to 50.0 mL with the mobile phase. Dilute 1.0 mL of this solution to 10.0 mL with the mobile phase.<\/p>\n Reference solution (b): Dissolve 5 mg of foscarnet impurity B CRS in the mobile phase, add 2 mL of the test solution and dilute to 50 mL with the mobile phase.<\/p>\n Reference solution (c): Dissolve the contents of a vial of foscarnet impurity mixture CRS (impurities A and C) in 1 mL of mobile phase.<\/p>\n Column:<\/p>\n \u2014 size: l = 0.10 m, \u00d8 = 4.6 mm;<\/p>\n \u2014 stationary phase: octadecylsilyl silica gel for chromatography R (3 \u03bcm).<\/p>\n Mobile phase: Dissolve 3.22 g of sodium sulfate decahydrate R in water for chromatography R, add 3 mL of glacial acetic acid R and 6 mL of a 44.61 g\/L solution of sodium pyrophosphate R and dilute to 1000 mL with water for chromatography R (solution A); dissolve 3.22 g of sodium sulfate decahydrate R in water for chromatography R, add 6.8 g of sodium acetate R and 6 mL of a 44.61 g\/L solution of sodium pyrophosphate R and dilute to 1000 mL with water for chromatography R (solution B). Mix about 700 mL of solution A and about 300 mL of solution B to obtain a solution of pH 4.4. To 1000 mL of this solution, add 0.25 g of tetrahexylammonium hydrogen sulfate R and 100 mL of methanol R1.<\/p>\n Flow rate 1.0 mL\/min.<\/p>\n Detection Spectrophotometer at 230 nm.<\/p>\n Injection 40 \u03bcL.<\/p>\n Run time 2.5 times the retention time of foscarnet.<\/p>\n Identification of impurities: Use the chromatogram supplied with foscarnet impurity mixture CRS and the chromatogram obtained with reference solution (c) to identify the peaks due to impurities A and C; use the chromatogram obtained with reference solution (b) to identify the peak due to impurity B.<\/p>\n Relative retention: With reference to foscarnet (retention time = about 5 min): impurity A = about 0.7; System suitability Reference solution (b):<\/p>\n \u2014 resolution: minimum 7.0 between the peaks due to foscarnet and impurity B.<\/p>\n Limits:<\/p>\n \u2014 impurities A, B, C: for each impurity, not more than the area of the principal peak in the chromatogram obtained with reference solution (a) (0.2 per cent);<\/p>\n \u2014 unspecified impurities: for each impurity, not more than 0.25 times the area of the principal peak in the \u2014 total: not more than twice the area of the principal peak in the chromatogram obtained with reference solution (a) (0.4 per cent);<\/p>\n \u2014 disregard limit: 0.2 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.04 per cent); disregard any peak with a relative retention less than 0.6.<\/p>\n Liquid chromatography (2.2.29).<\/p>\n Test solution: Dissolve 60.0 mg of the substance to be examined in water R and dilute to 25.0 mL with the same solvent.<\/p>\n Reference solution (a): Dissolve 28 mg of sodium dihydrogen phosphate monohydrate R in water R and dilute to 100 mL with the same solvent.<\/p>\n Reference solution (b): Dissolve 43 mg of sodium phosphite pentahydrate R in water R and dilute to 100 mL with the same solvent.<\/p>\n Reference solution (c): Dilute 1.0 mL of reference solution (a) and 1.0 mL of reference solution (b) to 25 mL with water R.<\/p>\n Reference solution (d): Dilute 3 mL of reference solution (a) and 3 mL of reference solution (b) to 25 mL with water R.<\/p>\n Column:<\/p>\n \u2014 size: l = 0.05 m, \u00d8 = 4.6 mm;<\/p>\n \u2014 stationary phase: anion-exchange resin R.<\/p>\n Mobile phase Dissolve 0.102 g of potassium hydrogen phthalate R in water for chromatography R, add 2.5 mL of 1 M nitric acid and dilute to 1000 mL with water for chromatography R.<\/p>\n Flow rate 1.4 mL\/min.<\/p>\n Detection Spectrophotometer at 290 nm (indirect detection).<\/p>\n Injection 20 \u03bcL of the test solution and reference solutions (c) and (d).<\/p>\n System suitability Reference solution (d):<\/p>\n \u2014 resolution: minimum 2.0 between the peaks due to phosphate (1 peak) and phosphite;<\/p>\n \u2014 signal-to-noise ratio: minimum 10 for the principal peak.<\/p>\n Limits:<\/p>\n \u2014 phosphate: not more than the area of the corresponding peak in the chromatogram obtained with reference solution (c) (0.3 per cent);<\/p>\n \u2014 phosphite: not more than the area of the corresponding peak in the chromatogram obtained with reference solution (c) (0.3 per cent).<\/p>\n 35.0 per cent to 37.0 per cent, determined on 1.000 g by drying in an oven at 150 \u00b0C.<\/p>\n Less than 83.3 IU\/g, if intended for use in the manufacture of parenteral preparations without a further appropriate procedure for the removal of bacterial endotoxins.<\/p>\n Dissolve 0.200 g in 50 mL of water R. Titrate with 0.05 M sulfuric acid, determining the end-point potentiometrically (2.2.20) at the 1 point of inflexion.<\/p>\n 1 mL of 0.05 M sulfuric acid is equivalent to 19.20 mg of CNa3<\/sub>O5<\/sub>P.<\/p>\n Protected from light.<\/p>\n Specified impurities A, B, C, D.<\/p>\n A. disodium (ethoxycarbonyl)phosphonate,<\/p>\n B. disodium (ethoxyoxydophosphanyl)formate,<\/p>\n C. ethyl sodium (ethoxycarbonyl)phosphonate,<\/p>\n D. ethyl (diethoxyphosphoryl)formate.<\/p>\n","protected":false},"excerpt":{"rendered":" (Foscarnet Sodium Hexahydrate, Ph. Eur. monograph 1520) CNa3O5P,6H2O\u00a0 \u00a0300.0\u00a0 \u00a034156-56-4 Action and use Antiviral (cytomegalovirus). Preparation Foscarnet Infusion DEFINITION Trisodium phosphonatoformate hexahydrate. Content 98.5 per cent to 101.0 per cent (dried substance). CHARACTERS Appearance White or almost white, crystalline powder. Solubility Soluble in water, practically insoluble in ethanol (96 per cent). IDENTIFICATION A. Infrared absorption…<\/p>\n","protected":false},"author":3,"featured_media":12467,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-12443","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\/12443","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=12443"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/12443\/revisions"}],"predecessor-version":[{"id":12470,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/12443\/revisions\/12470"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/12467"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=12443"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=12443"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=12443"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}DEFINITION<\/h2>\n
Content<\/h3>\n
CHARACTERS<\/h2>\n
Appearance<\/h3>\n
Solubility<\/h3>\n
IDENTIFICATION<\/h2>\n
TESTS<\/h2>\n
Solution S<\/h3>\n
Appearance of solution<\/h3>\n
pH (2.2.3)<\/h3>\n
Impurity D<\/h3>\n
\n\n
\n <\/td>\n Time
\n(min)<\/td>\nTemperature
\n(\u00b0C)<\/td>\n<\/tr>\n\n Column<\/td>\n \u00a00 – 8<\/td>\n 100 \u2192 180<\/td>\n<\/tr>\n \n Injection port<\/td>\n <\/td>\n 200<\/td>\n<\/tr>\n \n Detector<\/td>\n <\/td>\n 250<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Related substances<\/h3>\n
\nimpurity B = about 1.5; impurity C = about 2.0.<\/p>\n
\nchromatogram obtained with reference solution (a) (0.05 per cent);<\/p>\nPhosphate and phosphite<\/h3>\n
Loss on drying (2.2.32)<\/h4>\n
Bacterial endotoxins (2.6.14)<\/h4>\n
ASSAY<\/h2>\n
STORAGE<\/h2>\n
IMPURITIES<\/h2>\n
![\"Foscarnet](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/1-124-300x163.jpg\")
<\/p>\n![\"Foscarnet](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/2-123-300x163.jpg\")
<\/p>\n![\"Foscarnet](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/3-115-300x163.jpg\")
<\/p>\n![\"Foscarnet](\"https:\/\/nhathuocngocanh.com\/bp\/wp-content\/uploads\/2025\/10\/4-105-300x163.jpg\")
<\/p>\n