{"id":26613,"date":"2025-11-05T19:40:49","date_gmt":"2025-11-05T12:40:49","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=26613"},"modified":"2025-11-06T17:48:29","modified_gmt":"2025-11-06T10:48:29","slug":"oseltamivir-phosphate","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/oseltamivir-phosphate\/","title":{"rendered":"Oseltamivir Phosphate"},"content":{"rendered":"

Edition: BP 2025 (Ph. Eur. 11.6 update)<\/p>\n

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

Treatment of influenza.<\/p>\n

Preparation<\/strong><\/p>\n

Paediatric Oseltamivir Oral Solution Ph Eur<\/p>\n

DEFINITION<\/h2>\n
Ethyl (3R,4R,5S)-4-acetamido-5-amino-3-(1-ethylpropoxy)cyclohex-1-ene-1-carboxylate phosphate.<\/p>\n
Content<\/strong><\/p>\n
98.0 per cent to 102.0 per cent (anhydrous substance).<\/p>\n
CHARACTERS<\/h2>\n
Appearance<\/h3>\n
White or almost white powder.<\/p>\n
Solubility<\/h3>\n
Freely soluble in water and in methanol, practically insoluble in methylene chloride. It shows polymorphism (5.9).<\/p>\n
IDENTIFICATION<\/h2>\n
A. Specific optical rotation (see Tests).<\/p>\n
B. Infrared absorption spectrophotometry (2.2.24).<\/p>\n
Comparison\u00a0 oseltamivir phosphate (impurity B-free) CRS.<\/p>\n
If the spectra obtained show differences, dissolve the substance to be examined and the reference substance separately in methanol R, evaporate to dryness and record new spectra using the residues.<\/p>\n
C. Dissolve 200 mg in 10 mL of water R. It gives reaction (b) of phosphates (2.3.1).<\/p>\n
TESTS<\/h2>\n
Specific optical rotation (2.2.7)<\/strong><\/p>\n
-30.7 to -32.6 (anhydrous substance), measured at 25 \u00b0C.<\/p>\n
Dissolve 0.50 g in water R and dilute to 50.0 mL with the same solvent.<\/p>\n
Impurity B<\/h3>\n
Liquid chromatography (2.2.29) coupled with mass spectrometry (2.2.43).<\/p>\n
Test solution\u00a0 Dissolve 0.100 g of the substance to be examined in water for chromatography R and dilute to 10.0 mL with the same solvent.<\/p>\n
Reference solution (a)\u00a0 Dissolve 2.5 mg of oseltamivir impurity B CRS in 5.0 mL of anhydrous ethanol R and dilute to 50.0 mL with water for chromatography R. Dilute 2.0 mL of the solution to 100.0 mL with water for chromatography R.<\/p>\n
Reference solution (b) Dissolve 50.0 mg of oseltamivir phosphate (impurity B-free) CRS in reference solution (a) and dilute to 5.0 mL with the same solution.<\/p>\n
Column:<\/p>\n
\u2014 size: l = 0.05 m, \u00d8 = 3.0 mm;<\/p>\n
\u2014 stationary phase: end-capped octadecylsilyl silica gel for chromatography R (5 \u00b5m);<\/p>\n
\u2014 temperature: 40 \u00b0C.<\/p>\n
Mobile phase\u00a0 Mix 10 volumes of a 1.54 g\/L solution of ammonium acetate R in water for chromatography R, 30 volumes of acetonitrile R1 and 60 volumes of water for chromatography R.<\/p>\n
Flow rate\u00a0 1.5 mL\/min.<\/p>\n
Post-column split ratio\u00a0 Use a split ratio suitable for the mass detector (e.g. 1:3).<\/p>\n
Detection:<\/p>\n
\u2014 mass detector: the following settings have been found to be suitable and are given as examples; if the detector has different setting parameters, adjust the detector settings so as to comply with the system suitability criterion:<\/p>\n
\u2014 ionisation: ESI-positive;<\/p>\n
\u2014 detection m\/z: 356.2;<\/p>\n
\u2014 dwell: 580 ms;<\/p>\n
\u2014 gain EMV: 1;<\/p>\n
\u2014 fragmentator voltage: 120 V;<\/p>\n
\u2014 gas temperature: 350 \u00b0C;<\/p>\n
\u2014 drying gas flow: 13 L\/min,<\/p>\n
\u2014 nebuliser pressure: 345 kPa;<\/p>\n
\u2014 capillary voltage (Vcap): 3 kV.<\/p>\n
Injection\u00a0 1 \u00b5L of the test solution and reference solution (b).<\/p>\n
Run time\u00a0 3 min.<\/p>\n
System suitability\u00a0 Reference solution (b):<\/p>\n
\u2014 repeatability: maximum relative standard deviation of 15 per cent determined on 6 injections.<\/p>\n
Limit:<\/p>\n
\u2014 impurity B: not more than the area of the corresponding peak in the chromatogram obtained with reference solution (b) (100 ppm).<\/p>\n
Impurity H<\/h3>\n
Gas chromatography (2.2.28).<\/p>\n
Silylation reagent\u00a0 Mix 1.0 mL of chlorotrimethylsilane R, 2.0 mL of hexamethyldisilazane R and 10.0 mL of anhydrous pyridine R.<\/p>\n
Test solution\u00a0 Introduce 15.0 mg of the substance to be examined into a 2 mL vial and add 1.0 mL of the silylation reagent. Close the vial, shake and heat at 60 \u00b0C for 20 min. Centrifuge and discard the precipitate.<\/p>\n
Reference solution\u00a0 Introduce 15.0 mg of oseltamivir impurity H CRS into a 2 mL vial and add 1.0 mL of anhydrous pyridine R. Close the vial and shake (solution A). (Note: impurity H is hygroscopic.) Introduce<\/p>\n
15.0 mg of the substance to be examined into another 2 mL vial and add 1.0 mL of the silylation reagent. Close the vial, shake and heat at 60 \u00b0C for 20 min.<\/p>\n
Centrifuge and discard the precipitate (solution B). Introduce 10.0 \u00b5L of solution A and 10.0 \u00b5L of solution B into a volumetric flask and dilute to 10.0 mL with anhydrous pyridine R.<\/p>\n
Column:<\/p>\n
\u2014 material: fused silica;<\/p>\n
\u2014 size: l = 30 m, \u00d8 = 0.32 mm;<\/p>\n
\u2014 stationary phase: methylpolysiloxane R (film thickness 0.25 \u00b5m).<\/p>\n
Carrier gas helium for chromatography R. Flow rate 1.2 mL\/min.<\/p>\n
Split ratio\u00a0 1:50.<\/p>\n
Temperature:<\/p>\n\n\n\n\n\n\n\n\n
<\/td>\n Time (min)<\/strong><\/td>\n Temperature (\u00b0C)<\/strong><\/td>\n<\/tr>\n
Column<\/td>\n 0 – 2<\/td>\n 180<\/td>\n<\/tr>\n
2 – 11<\/td>\n 180 \u2192 250<\/td>\n<\/tr>\n
11 – 21<\/td>\n 250<\/td>\n<\/tr>\n
Injection port<\/td>\n 260<\/td>\n<\/tr>\n
Detector<\/td>\n 260<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
Detection\u00a0 Flame ionisation.<\/p>\n
Injection\u00a0 1 \u00b5L.<\/p>\n
Relative retention\u00a0 With reference to oseltamivir phosphate (retention time = about 10 min): impurity H = about 0.5.<\/p>\n
System suitability\u00a0 Reference solution:<\/p>\n
\u2014 repeatability: maximum relative standard deviation of 5 per cent for the peak due to impurity H after 6 injections.<\/p>\n
Limit:<\/p>\n
\u2014 impurity H: not more than 1.5 times the area of the corresponding peak in the chromatogram obtained with the reference solution (0.15 per cent).<\/p>\n
Related substances<\/h3>\n
Liquid chromatography (2.2.29).<\/p>\n
Solvent mixture\u00a0 acetonitrile R1, methanol R2, water for chromatography R (135:245:620 V\/V\/V).<\/p>\n
Test solution\u00a0 Dissolve 50.0 mg of the substance to be examined in the solvent mixture and dilute to 50.0 mL with the solvent mixture.<\/p>\n
Reference solution (a)\u00a0 Dilute 1.0 mL of the test solution to 100.0 mL with the solvent mixture. Dilute 1.0 mL of this solution to 10.0 mL with the solvent mixture.<\/p>\n
Reference solution (b)\u00a0 Dissolve 5 mg of oseltamivir impurity A CRS and 5.0 mg of oseltamivir impurity C CRS in the solvent mixture and dilute to 50.0 mL with the solvent mixture. Dilute 1.0 mL of the solution to 10.0 mL with the solvent mixture.<\/p>\n
Reference solution (c)\u00a0 Dissolve 50.0 mg of oseltamivir phosphate (impurity B-free) CRS in the solvent mixture and dilute to 50.0 mL with the solvent mixture.<\/p>\n
Column:<\/p>\n
\u2014 size: l = 0.25 m, \u00d8 = 4.6 mm;<\/p>\n
\u2014 stationary phase: end-capped octylsilyl silica gel for chromatography R (5 \u00b5m);<\/p>\n
\u2014 temperature: 50 \u00b0C.<\/p>\n
Mobile phase\u00a0 Mix 135 volumes of acetonitrile R1, 245 volumes of methanol R2 and 620 volumes of a 6.8 g\/L solution of potassium dihydrogen phosphate R in water for chromatography R, adjusted to pH 6.0 with a 1 M potassium hydroxide solution prepared from potassium hydroxide R.<\/p>\n
Flow rate\u00a0 1.2 mL\/min.<\/p>\n
Detection\u00a0 Spectrophotometer at 207 nm.<\/p>\n
Injection\u00a0 15 \u00b5L of the test solution and reference solutions (a) and (b).<\/p>\n
Run time\u00a0 Twice the retention time of oseltamivir phosphate.<\/p>\n
Relative retention\u00a0 With reference to oseltamivir phosphate (retention time = about 17 min): impurity A = about 0.16; impurity C = about 0.17.<\/p>\n
System suitability\u00a0 Reference solution (b):<\/p>\n
\u2014 resolution: minimum 1.5 between the peaks due to impurities A and C.<\/p>\n
Limits:<\/p>\n
\u2014 impurity C: not more than 0.3 times the area of the corresponding peak 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 principal peak in the chromatogram obtained with reference solution (a) (0.10 per cent);<\/p>\n
\u2014 total: not more than 7 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.7 per cent);<\/p>\n
\u2014 disregard limit: 0.5 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.05 per cent).<\/p>\n
Water (2.5.12)<\/strong><\/p>\n
Maximum 0.5 per cent, determined on 0.500 g.<\/p>\n
ASSAY<\/h2>\n
Liquid chromatography (2.2.29) as described in the test for related substances with the following modification.<\/p>\n
Injection\u00a0 Test solution and reference solution (c).<\/p>\n
Calculate the percentage content of C_{16<\/sub>H_{31<\/sub>N_{2<\/sub>O_{8<\/sub>P from the declared content of oseltamivir phosphate\u00a0(impurity B-free) CRS.<\/p>\n}}}}
STORAGE<\/h2>\n
Protected from light.<\/p>\n
IMPURITIES<\/h2>\n
Specified impurities\u00a0 B, C, H.<\/em><\/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)\u00a0 A, D, E, F, G.<\/em><\/p>\n
$\"Oseltamivir$ <\/p>\n
A. (3R,4R,5S)-5-acetamido-4-amino-3-(1-ethylpropoxy)cyclohex-1-ene-1-carboxylic acid,<\/p>\n
$\"Oseltamivir$ <\/p>\n
B. ethyl\u00a0 (1R,2R,3S,4R,5S)-4-acetamido-5-amino-2-azido-3(1-ethylpropoxy)cyclohexanecarboxylate,<\/p>\n
$\"Oseltamivir$ <\/p>\n
C. (3R,4R,5S)-4-acetamido-5-amino-3-(1-ethylpropoxy)cyclohex-1-ene-1-carboxylic acid,<\/p>\n
$\"Oseltamivir$ <\/p>\n
D. ethyl 4-acetamido-3-hydroxybenzoate,<\/p>\n
$\"Oseltamivir$ <\/p>\n
E. methyl\u00a0 (3R,4R,5S)-4-acetamido-5-amino-3-(1-ethylpropoxy)cyclohex-1-ene-1-carboxylate,<\/p>\n
$\"Oseltamivir$ <\/p>\n
F. ethyl\u00a0 (3R,4R,5S)-4-acetamido-5-amino-3-(1-methylpropoxy)cyclohex-1-ene-1-carboxylate,<\/p>\n
$\"Oseltamivir$ <\/p>\n
G. ethyl\u00a0 (3R,4R,5S)-5-acetamido-4-amino-3-(1-ethylpropoxy)cyclohex-1-ene-1-carboxylate,<\/p>\n
$\"Oseltamivir$ <\/p>\n
H. tributylphosphane oxide.<\/p>\n
\n
Ph Eur<\/p>\n","protected":false},"excerpt":{"rendered":"
Edition: BP 2025 (Ph. Eur. 11.6 update) Action and use Treatment of influenza. Preparation Paediatric Oseltamivir Oral Solution Ph Eur DEFINITION Ethyl (3R,4R,5S)-4-acetamido-5-amino-3-(1-ethylpropoxy)cyclohex-1-ene-1-carboxylate phosphate. Content 98.0 per cent to 102.0 per cent (anhydrous substance). CHARACTERS Appearance White or almost white powder. Solubility Freely soluble in water and in methanol, practically insoluble in methylene chloride. It…<\/p>\n","protected":false},"author":5,"featured_media":26614,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-26613","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\/26613","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=26613"}],"version-history":[{"count":4,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/26613\/revisions"}],"predecessor-version":[{"id":27376,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/26613\/revisions\/27376"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/26614"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=26613"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=26613"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=26613"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

<\/td>\n	Time (min)<\/strong><\/td>\n	Temperature (\u00b0C)<\/strong><\/td>\n<\/tr>\n
Column<\/td>\n	0 – 2<\/td>\n	180<\/td>\n<\/tr>\n
2 – 11<\/td>\n	180 \u2192 250<\/td>\n<\/tr>\n
11 – 21<\/td>\n	250<\/td>\n<\/tr>\n
Injection port<\/td>\n	260<\/td>\n<\/tr>\n
Detector<\/td>\n	260<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Detection\u00a0 Flame ionisation.<\/p>\n Injection\u00a0 1 \u00b5L.<\/p>\n Relative retention\u00a0 With reference to oseltamivir phosphate (retention time = about 10 min): impurity H = about 0.5.<\/p>\n System suitability\u00a0 Reference solution:<\/p>\n \u2014 repeatability: maximum relative standard deviation of 5 per cent for the peak due to impurity H after 6 injections.<\/p>\n Limit:<\/p>\n \u2014 impurity H: not more than 1.5 times the area of the corresponding peak in the chromatogram obtained with the reference solution (0.15 per cent).<\/p>\n Related substances<\/h3>\n Liquid chromatography (2.2.29).<\/p>\n Solvent mixture\u00a0 acetonitrile R1, methanol R2, water for chromatography R (135:245:620 V\/V\/V).<\/p>\n Test solution\u00a0 Dissolve 50.0 mg of the substance to be examined in the solvent mixture and dilute to 50.0 mL with the solvent mixture.<\/p>\n Reference solution (a)\u00a0 Dilute 1.0 mL of the test solution to 100.0 mL with the solvent mixture. Dilute 1.0 mL of this solution to 10.0 mL with the solvent mixture.<\/p>\n Reference solution (b)\u00a0 Dissolve 5 mg of oseltamivir impurity A CRS and 5.0 mg of oseltamivir impurity C CRS in the solvent mixture and dilute to 50.0 mL with the solvent mixture. Dilute 1.0 mL of the solution to 10.0 mL with the solvent mixture.<\/p>\n Reference solution (c)\u00a0 Dissolve 50.0 mg of oseltamivir phosphate (impurity B-free) CRS in the solvent mixture and dilute to 50.0 mL with the solvent mixture.<\/p>\n Column:<\/p>\n \u2014 size: l = 0.25 m, \u00d8 = 4.6 mm;<\/p>\n \u2014 stationary phase: end-capped octylsilyl silica gel for chromatography R (5 \u00b5m);<\/p>\n \u2014 temperature: 50 \u00b0C.<\/p>\n Mobile phase\u00a0 Mix 135 volumes of acetonitrile R1, 245 volumes of methanol R2 and 620 volumes of a 6.8 g\/L solution of potassium dihydrogen phosphate R in water for chromatography R, adjusted to pH 6.0 with a 1 M potassium hydroxide solution prepared from potassium hydroxide R.<\/p>\n Flow rate\u00a0 1.2 mL\/min.<\/p>\n Detection\u00a0 Spectrophotometer at 207 nm.<\/p>\n Injection\u00a0 15 \u00b5L of the test solution and reference solutions (a) and (b).<\/p>\n Run time\u00a0 Twice the retention time of oseltamivir phosphate.<\/p>\n Relative retention\u00a0 With reference to oseltamivir phosphate (retention time = about 17 min): impurity A = about 0.16; impurity C = about 0.17.<\/p>\n System suitability\u00a0 Reference solution (b):<\/p>\n \u2014 resolution: minimum 1.5 between the peaks due to impurities A and C.<\/p>\n Limits:<\/p>\n \u2014 impurity C: not more than 0.3 times the area of the corresponding peak 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 principal peak in the chromatogram obtained with reference solution (a) (0.10 per cent);<\/p>\n \u2014 total: not more than 7 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.7 per cent);<\/p>\n \u2014 disregard limit: 0.5 times the area of the principal peak in the chromatogram obtained with reference solution (a) (0.05 per cent).<\/p>\n Water (2.5.12)<\/strong><\/p>\n Maximum 0.5 per cent, determined on 0.500 g.<\/p>\n ASSAY<\/h2>\n Liquid chromatography (2.2.29) as described in the test for related substances with the following modification.<\/p>\n Injection\u00a0 Test solution and reference solution (c).<\/p>\n Calculate the percentage content of C_{16<\/sub>H_{31<\/sub>N_{2<\/sub>O_{8<\/sub>P from the declared content of oseltamivir phosphate\u00a0(impurity B-free) CRS.<\/p>\n}}}} STORAGE<\/h2>\n Protected from light.<\/p>\n IMPURITIES<\/h2>\n Specified impurities\u00a0 B, C, H.<\/em><\/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)\u00a0 A, D, E, F, G.<\/em><\/p>\n $\"Oseltamivir$ <\/p>\n A. (3R,4R,5S)-5-acetamido-4-amino-3-(1-ethylpropoxy)cyclohex-1-ene-1-carboxylic acid,<\/p>\n $\"Oseltamivir$ <\/p>\n B. ethyl\u00a0 (1R,2R,3S,4R,5S)-4-acetamido-5-amino-2-azido-3(1-ethylpropoxy)cyclohexanecarboxylate,<\/p>\n $\"Oseltamivir$ <\/p>\n C. (3R,4R,5S)-4-acetamido-5-amino-3-(1-ethylpropoxy)cyclohex-1-ene-1-carboxylic acid,<\/p>\n $\"Oseltamivir$ <\/p>\n D. ethyl 4-acetamido-3-hydroxybenzoate,<\/p>\n $\"Oseltamivir$ <\/p>\n E. methyl\u00a0 (3R,4R,5S)-4-acetamido-5-amino-3-(1-ethylpropoxy)cyclohex-1-ene-1-carboxylate,<\/p>\n $\"Oseltamivir$ <\/p>\n F. ethyl\u00a0 (3R,4R,5S)-4-acetamido-5-amino-3-(1-methylpropoxy)cyclohex-1-ene-1-carboxylate,<\/p>\n $\"Oseltamivir$ <\/p>\n G. ethyl\u00a0 (3R,4R,5S)-5-acetamido-4-amino-3-(1-ethylpropoxy)cyclohex-1-ene-1-carboxylate,<\/p>\n $\"Oseltamivir$ <\/p>\n H. tributylphosphane oxide.<\/p>\n \n Ph Eur<\/p>\n","protected":false},"excerpt":{"rendered":" Edition: BP 2025 (Ph. Eur. 11.6 update) Action and use Treatment of influenza. Preparation Paediatric Oseltamivir Oral Solution Ph Eur DEFINITION Ethyl (3R,4R,5S)-4-acetamido-5-amino-3-(1-ethylpropoxy)cyclohex-1-ene-1-carboxylate phosphate. Content 98.0 per cent to 102.0 per cent (anhydrous substance). CHARACTERS Appearance White or almost white powder. Solubility Freely soluble in water and in methanol, practically insoluble in methylene chloride. It…<\/p>\n","protected":false},"author":5,"featured_media":26614,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-26613","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\/26613","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=26613"}],"version-history":[{"count":4,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/26613\/revisions"}],"predecessor-version":[{"id":27376,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/26613\/revisions\/27376"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/26614"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=26613"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=26613"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=26613"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

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

Solubility<\/h3>\nFreely soluble in water and in methanol, practically insoluble in methylene chloride. It shows polymorphism (5.9).<\/p>\n

TESTS<\/h2>\nSpecific optical rotation (2.2.7)<\/strong><\/p>\n-30.7 to -32.6 (anhydrous substance), measured at 25 \u00b0C.<\/p>\nDissolve 0.50 g in water R and dilute to 50.0 mL with the same solvent.<\/p>\n

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

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

Solubility<\/h3>\n
Freely soluble in water and in methanol, practically insoluble in methylene chloride. It shows polymorphism (5.9).<\/p>\n

TESTS<\/h2>\n
Specific optical rotation (2.2.7)<\/strong><\/p>\n
-30.7 to -32.6 (anhydrous substance), measured at 25 \u00b0C.<\/p>\n
Dissolve 0.50 g in water R and dilute to 50.0 mL with the same solvent.<\/p>\n

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