Action and use<\/strong><\/p>\n Antidote to folic acid antagonists.<\/p>\n Calcium (2S)-2-[4-[[[(6S)-2-amino-5-formyl-4-oxo-1,4,5,6,7,8-hexahydropteridin-6- \u2014 calcium levofolinate (C20H21CaN7O7; Mr 511.5): 97.0 per cent to 102.0 per cent (anhydrous substance);<\/p>\n \u2014 calcium (Ca; Ar 40.08): 7.54 per cent to 8.14 per cent (anhydrous substance).<\/p>\n It contains a variable quantity of water.<\/p>\n White or light yellow, amorphous or crystalline, hygroscopic powder.<\/p>\n Slightly soluble in water, practically insoluble in acetone and in ethanol (96 per cent).<\/p>\n It shows polymorphism (5.9).<\/p>\n First identification: A, B, D.<\/p>\n Second identification: A, C, D.<\/p>\n A. Specific optical rotation (see Tests).<\/p>\n B. Infrared absorption spectrophotometry (2.2.24).<\/p>\n Comparison: calcium folinate CRS.<\/p>\n If the spectra obtained show differences, dissolve the substance to be examined and the reference substance separately in the minimum quantity of water R and add dropwise sufficient acetone R to produce a precipitate. Allow to stand for 15 min, collect the precipitate by centrifugation, wash the precipitate twice with a minimum quantity of acetone R and dry. Record new spectra using the residues.<\/p>\n C. Thin-layer chromatography (2.2.27).<\/p>\n Test solution: Dissolve 15 mg of the substance to be examined in a 3 per cent V\/V solution of ammonia R and dilute to 5 mL with the same solvent.<\/p>\n Reference solution: Dissolve 15 mg of calcium folinate CRS in a 3 per cent V\/V solution of ammonia R and dilute to 5 mL with the same solvent.<\/p>\n Plate: cellulose for chromatography F254 R as the coating substance.<\/p>\n Mobile phase: The lower layer of a mixture of 1 volume of isoamyl alcohol R and 10 volumes of a 50 g\/L solution of citric acid monohydrate R previously adjusted to pH 8 with ammonia R.<\/p>\n Application: 5 \u03bcL.<\/p>\n Development: Over 2\/3 of the plate.<\/p>\n Drying: In air.<\/p>\n Detection: Examine in ultraviolet light at 254 nm.<\/p>\n Results: The principal spot in the chromatogram obtained with the test solution is similar in position and size to the principal spot in the chromatogram obtained with the reference solution.<\/p>\n D. It gives reaction (b) of calcium (2.3.1).<\/p>\n Carry out the tests as rapidly as possible, protected from actinic light.<\/p>\n Dissolve 0.40 g in carbon dioxide-free water R, heating at 40 \u00b0C if necessary, and dilute to 50.0 mL with the same solvent.<\/p>\n Solution S is clear (2.2.1).<\/p>\n 7.5 to 8.5 for solution S.<\/p>\n -15.0 to -10.0 (anhydrous substance), measured at 25 \u00b0C.<\/p>\n Dissolve 0.200 g in tris(hydroxymethyl)aminomethane solution R previously adjusted to pH 8.1 with sodium hydroxide solution R or hydrochloric acid R1 and dilute to 20.0 mL with the same solvent.<\/p>\n Maximum 0.25, determined at 420 nm on solution S.<\/p>\n Head-space gas chromatography (2.2.28): use the standard additions method.<\/p>\n Test solution: Dissolve 0.25 g of the substance to be examined in water R and dilute to 10.0 mL with the same solvent.<\/p>\n Reference solution: Dilute 0.750 g of anhydrous ethanol R to 1000.0 mL with water R.<\/p>\n Column:<\/p>\n \u2014 material: fused silica;<\/p>\n \u2014 size: l = 10 m, \u00d8 = 0.32 mm;<\/p>\n \u2014 stationary phase: styrene-divinylbenzene copolymer R.<\/p>\n Carrier gas: nitrogen for chromatography R.<\/p>\n Flow rate: 4 mL\/min.<\/p>\n Static head-space conditions that may be used:<\/p>\n \u2014 equilibration temperature: 80 \u00b0C;<\/p>\n \u2014 equilibration time: 20 min;<\/p>\n \u2014 pressurisation time: 30 s.<\/p>\n Temperature:<\/p>\n Detection: Flame ionisation.<\/p>\n Injection: At least 3 times.<\/p>\n Limit:<\/p>\n \u2014 ethanol: maximum 3.0 per cent.<\/p>\n Liquid chromatography (2.2.29). Prepare the solutions immediately before use.<\/p>\n Test solution: Dissolve 10.0 mg of the substance to be examined in water R and dilute to 10.0 mL with the same solvent.<\/p>\n Reference solution (a): Dissolve 10.0 mg of calcium folinate CRS in water R and dilute to 10.0 mL with the same solvent.<\/p>\n Reference solution (b): Dilute 1.0 mL of the test solution to 100.0 mL with water R. Dilute 1.0 mL of this solution to 10.0 mL with water R.<\/p>\n Reference solution (c): Dissolve 5 mg of calcium folinate for system suitability A CRS (containing impurities A, B, C, D, E, F and I) in 5 mL of a 2.5 g\/L solution of sodium hydrogen carbonate R.<\/p>\n Column:<\/p>\n \u2014 size: l = 0.25 m, \u00d8 = 4 mm;<\/p>\n \u2014 stationary phase: end-capped octadecylsilyl silica gel for chromatography R (5 \u03bcm);<\/p>\n \u2014 temperature: 40 \u00b0C.<\/p>\n Mobile phase: Mix 165 mL of methanol R and 835 mL of a solution containing 4.0 mL of tetrabutylammonium dihydrogen phosphate solution R and 1.42 g of disodium hydrogen phosphate dihydrate R in water for chromatography R, previously adjusted to pH 7.7 with phosphoric acid R or dilute sodium hydroxide solution R.<\/p>\n Flow rate: 1.25 mL\/min.<\/p>\n Detection: Spectrophotometer at 254 nm.<\/p>\n Injection: 10 \u03bcL of the test solution and reference solutions (b) and (c).<\/p>\n Run time: 4 times the retention time of folinic acid.<\/p>\n Identification of impurities: Use the chromatogram supplied with calcium folinate for system suitability A CRS and the chromatogram obtained with reference solution (c) to identify the peaks due to impurities A, B, C, D, E, F and I.<\/p>\n Relative retention: With reference to folinic acid (retention time = about 12.0 min): impurity E = about 0.4; impurity A = about 0.6; impurity F = about 0.7; impurity B = about 0.8; impurity I = about 1.3 (may be eluted as 1 or 2 peaks); impurity D = about 2.1; impurity C = about 2.6.<\/p>\n System suitability: Reference solution (c):<\/p>\n \u2014 resolution: minimum 2.0 between the peaks due to impurities A and F.<\/p>\n Calculation of percentage contents:<\/p>\n \u2014 correction factors: multiply the peak areas of the following impurities by the corresponding correction factor: impurity A = 0.6; impurity B = 0.5; impurity C = 0.6; impurity D = 0.3; impurity E = 0.6; impurity F = 0.6; impurity I = 0.6;<\/p>\n \u2014 for each impurity, use the concentration of calcium levofolinate hydrate in reference solution (b).<\/p>\n Limits:<\/p>\n \u2014 impurities A, E: for each impurity, maximum 0.3 per cent;<\/p>\n \u2014 impurities B, C, D, F: for each impurity, maximum 0.2 per cent;<\/p>\n \u2014 impurity I: maximum 0.2 per cent, for the sum of the areas of the 2 peaks;<\/p>\n \u2014 unspecified impurities: for each impurity, maximum 0.20 per cent;<\/p>\n \u2014 total: maximum 1.5 per cent;<\/p>\n \u2014 reporting threshold: 0.05 per cent.<\/p>\n The thresholds indicated under Related substances (Table 2034.-1) in the general monograph Substances for pharmaceutical use (2034) do not apply.<\/p>\n Liquid chromatography (2.2.29): use the normalisation procedure.<\/p>\n Test solution: Dissolve 50.0 mg of the substance to be examined in water R and dilute to 100.0 mL with the same solvent.<\/p>\n Reference solution (a): Dissolve 10.0 mg of calcium folinate CRS in water R and dilute to 20.0 mL with the same solvent.<\/p>\n Reference solution (b): Dilute 1.0 mL of reference solution (a) to 100.0 mL with water R.<\/p>\n Column:<\/p>\n \u2014 size: l = 0.15 m, \u00d8 = 4 mm;<\/p>\n \u2014 stationary phase: human albumin coated silica gel for chiral separation R (5 \u03bcm);<\/p>\n \u2014 temperature: 40 \u00b0C.<\/p>\n Mobile phase: Dissolve 9.72 g of sodium dihydrogen phosphate R in 890 mL of water for chromatography R and adjust to pH 5.0 with sodium hydroxide solution R; add 100 mL of 2-propanol R and 10 mL of acetonitrile R.<\/p>\n Flow rate: 1 mL\/min.<\/p>\n Detection: Spectrophotometer at 286 nm.<\/p>\n Injection: 10 \u03bcL.<\/p>\n Retention times: Levofolinic acid = about 9 min; impurity H = about 19 min.<\/p>\n System suitability:<\/p>\n \u2014 resolution: minimum 5.0 between the peaks due to levofolinic acid and impurity H in the chromatogram obtained with reference solution (a). The sum of the areas of the 2 peaks is 100 per cent. The peak area of impurity H is 48 per cent to 52 per cent. In the chromatogram obtained with reference solution (b) 2 clearly visible peaks are obtained.<\/p>\n Limit:<\/p>\n \u2014 impurity H: maximum 0.5 per cent.<\/p>\n Maximum 0.5 per cent.<\/p>\n Dissolve 0.300 g in 50 mL of water R heating at 40 \u00b0C if necessary. Add 10 mL of dilute nitric acid R and titrate with 0.005 M silver nitrate determining the end-point potentiometrically (2.2.20).<\/p>\n 1 mL of 0.005 M silver nitrate is equivalent to 0.177 mg of Cl.<\/p>\n (2.5.12): 10.0 per cent to 17.0 per cent.<\/p>\n Dissolve 0.100 g in a mixture of 15 mL of formamide R and 50 mL of the titration solvent. Stir for about 6 min before titrating and use a suitable titrant that does not contain pyridine.<\/p>\n Carry out the assays as rapidly as possible, protected from actinic light.<\/p>\n Dissolve 0.400 g in 150 mL of water R and dilute to 300 mL with the same solvent. Carry out the complexometric titration of calcium (2.5.11).<\/p>\n 1 mL of 0.1 M sodium edetate is equivalent to 4.008 mg of Ca.<\/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).<\/p>\n Calculate the percentage content of C20<\/sub>H21<\/sub>CaN7<\/sub>O7<\/sub> taking into account the assigned content of calcium folinate CRS.<\/p>\n In an airtight container, protected from light. If the substance is sterile, the container is also sterile and tamper-evident.<\/p>\n The label states, where applicable, that the substance is suitable for use in the manufacture of parenteral preparations.<\/p>\n Specified impurities A, B, C, D, E, F, 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. 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) G.<\/p>\n A. (2S)-2-(4-aminobenzamido)pentanedioic acid,<\/p>\n B. (2S)-2-[4-[[[(6R)-2-amino-5-formyl-4-oxo-1,4,5,6,7,8-hexahydropteridin-6-yl]methyl]\n(formyl)amino]benzamido]pentanedioic acid (5,10-diformyltetrahydrolevofolic acid),<\/p>\n C. (2S)-2-[4-[[(2-amino-4-oxo-1,4-dihydropteridin-6- yl)methyl]amino]benzamido]pentanedioic acid (folic acid),<\/p>\n D. (2S)-2-[4-[[(2-amino-4-oxo-1,4-dihydropteridin-6-yl)methyl](formyl)amino]benzamido]pentanedioic acid (10-formylfolic acid),<\/p>\n E. 4-[[[(6S)-2-amino-5-formyl-4-oxo-1,4,5,6,7,8-hexahydropteridin-6-yl]methyl]amino]benzoic acid ((6S)-5- formyltetrahydropteroic acid),<\/p>\n F. (2S)-2-[4-[[(2-amino-4-oxo-1,4,7,8-tetrahydropteridin-6-yl)methyl](formyl)amino]benzamido]pentanedioic acid (10- formyldihydrofolic acid),<\/p>\n G. (2S)-2-[4-[[(2-amino-4-oxo-1,4,7,8-tetrahydropteridin-6-yl)methyl]amino]benzamido]pentanedioic acid (dihydrofolic acid),<\/p>\n H. (2S)-2-[4-[[[(6R)-2-amino-5-formyl-4-oxo-1,4,5,6,7,8-hexahydropteridin-6-yl]methyl]amino]benzamido]pentanedioic acid (dextrofolinic acid),<\/p>\n I. (2S)-2-[4-[(6aR)-3-amino-1-oxo-1,4,5,6,6a,7-hexahydroimidazo[1,5-f]pteridin-8(9H)-yl]benzamido]pentanedioic acid ((6aR)-5,10-methylenetetrahydrofolic acid).<\/p>\n","protected":false},"excerpt":{"rendered":" Calcium Levofolinate Pentahydrate (Ph. Eur. monograph 1606) C20H21CaN7O7,xH2O\u00a0 \u00a0 \u00a0 511.5 (anhydrous substance) Action and use Antidote to folic acid antagonists. DEFINITION Calcium (2S)-2-[4-[[[(6S)-2-amino-5-formyl-4-oxo-1,4,5,6,7,8-hexahydropteridin-6- yl]methyl]amino]benzamido]pentanedioate hydrate. Content \u2014 calcium levofolinate (C20H21CaN7O7; Mr 511.5): 97.0 per cent to 102.0 per cent (anhydrous substance); \u2014 calcium (Ca; Ar 40.08): 7.54 per cent to 8.14 per cent (anhydrous…<\/p>\n","protected":false},"author":2,"featured_media":4662,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-4598","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\/4598","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=4598"}],"version-history":[{"count":4,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/4598\/revisions"}],"predecessor-version":[{"id":5325,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/4598\/revisions\/5325"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/4662"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=4598"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=4598"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=4598"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}DEFINITION<\/h2>\n
\nyl]methyl]amino]benzamido]pentanedioate hydrate.<\/p>\nContent<\/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)<\/h4>\n
Specific optical rotation (2.2.7)<\/h4>\n
Absorbance (2.2.25)<\/h4>\n
Ethanol<\/h3>\n
\n\n
\n <\/td>\n Time<\/strong>
\n(min)<\/strong><\/td>\nTemperature<\/strong>
\n(\u00b0C)<\/strong><\/td>\n<\/tr>\n\n Column<\/td>\n 0 – 14<\/td>\n 80 \u2192 220<\/td>\n<\/tr>\n \n Injection port<\/td>\n <\/td>\n 110<\/td>\n<\/tr>\n \n Detector<\/td>\n <\/td>\n 270<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Related substances<\/h3>\n
Impurity H<\/h3>\n
Chlorides<\/h3>\n
Water<\/h4>\n
ASSAY<\/h2>\n
Calcium<\/h3>\n
Calcium folinate<\/h4>\n
STORAGE<\/h2>\n
LABELLING<\/h2>\n
IMPURITIES<\/h2>\n
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