{"id":9894,"date":"2025-10-07T10:27:17","date_gmt":"2025-10-07T03:27:17","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=9894"},"modified":"2025-10-07T10:27:17","modified_gmt":"2025-10-07T03:27:17","slug":"disodium-hydrogen-phosphate","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/disodium-hydrogen-phosphate\/","title":{"rendered":"Disodium Hydrogen Phosphate"},"content":{"rendered":"

Anhydrous Disodium Hydrogen Phosphate<\/p>\n

(Disodium Phosphate, Ph. Eur. monograph 1509)<\/p>\n

Na_{2<\/sub>HPO_{4<\/sub> 142.0 7558-79-4<\/p>\n}}

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

Excipient.<\/p>\n

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

Phosphates Enema<\/p>\n

DEFINITION<\/h2>\n
Content<\/h3>\n
98.0 per cent to 101.0 per cent (dried substance).<\/p>\n
CHARACTERS<\/h2>\n
Appearance<\/h3>\n
White or almost white powder, hygroscopic.<\/p>\n
Solubility<\/h3>\n
Soluble in water, practically insoluble in ethanol (96 per cent).<\/p>\n
IDENTIFICATION<\/h2>\n
A. Solution S (see Tests) is slightly alkaline (2.2.4).<\/p>\n
B. Loss on drying (see Tests).<\/p>\n
C. Solution S gives reaction (b) of phosphates (2.3.1).<\/p>\n
D. Solution S gives reaction (a) of sodium (2.3.1).<\/p>\n
TESTS<\/h2>\n
Solution S<\/h3>\n
Dissolve 5.0 g in distilled water R and dilute to 100.0 mL with the same solvent.<\/p>\n
Appearance of solution<\/h3>\n
Solution S is clear (2.2.1) and colourless (2.2.2, Method II).<\/p>\n
Reducing substances<\/h3>\n
To 10 mL of solution S add 5 mL of dilute sulfuric acid R and 0.25 mL of a 3.2 g\/L solution of potassium permanganate R and heat on a water-bath for 5 min. The colour of the permanganate is not completely discharged.<\/p>\n
Monosodium phosphate<\/h3>\n
Maximum 2.5 per cent.<\/p>\n
From the volumes of 1 M sodium hydroxide (n1 mL, n2 mL and n3 mL) used in the assay, calculate the following ratio:<\/p>\n
n_{2<\/sub>-n_{3<\/sub>\/n_{3<\/sub>-n_{1<\/sub><\/p>\n}}}}
This ratio is not greater than 0.025.<\/p>\n
Chlorides (2.4.4)<\/h3>\n
Maximum 200 ppm.<\/p>\n
Dilute 5 mL of solution S to 15 mL with dilute nitric acid R.<\/p>\n
Sulfates (2.4.13)<\/h3>\n
Maximum 500 ppm.<\/p>\n
To 6 mL of solution S add 2 mL of dilute hydrochloric acid R and dilute to 15 mL with distilled water R.<\/p>\n
Iron (2.4.9)<\/h3>\n
Maximum 20 ppm, determined on solution S.<\/p>\n
Loss on drying (2.2.32)<\/h4>\n
Maximum 1.0 per cent, determined on 1.000 g by drying in an oven at 105 \u00b0C for 4 h.<\/p>\n
ASSAY<\/h2>\n
Dissolve 1.600 g (m) in 25.0 mL of carbon dioxide-free water R and add 25.0 mL of 1 M hydrochloric acid. Carry out a potentiometric titration (2.2.20) using 1 M sodium hydroxide. Read the volume added at the 1 inflexion point (n1 mL).<\/p>\n
Continue the titration to the 2 inflexion point (total volume of 1 M sodium hydroxide required, n2 mL). Carry out a blank titration (n3 mL).<\/p>\n
Calculate the percentage content of Na_{2<\/sub>HPO_{4<\/sub> from the following expression:<\/p>\n}}
1420(n_{3<\/sub>-n_{1<\/sub>)\/m(100-d)<\/p>\n}}
d = percentage loss on drying.<\/p>\n
STORAGE<\/h2>\n
In an airtight container.<\/p>\n","protected":false},"excerpt":{"rendered":"
Anhydrous Disodium Hydrogen Phosphate (Disodium Phosphate, Ph. Eur. monograph 1509) Na2HPO4 142.0 7558-79-4 Action and use Excipient. Preparation Phosphates Enema DEFINITION Content 98.0 per cent to 101.0 per cent (dried substance). CHARACTERS Appearance White or almost white powder, hygroscopic. Solubility Soluble in water, practically insoluble in ethanol (96 per cent). IDENTIFICATION A. Solution S (see…<\/p>\n","protected":false},"author":3,"featured_media":9912,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-9894","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\/9894","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=9894"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/9894\/revisions"}],"predecessor-version":[{"id":9914,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/9894\/revisions\/9914"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/9912"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=9894"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=9894"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=9894"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

Content<\/h3>\n98.0 per cent to 101.0 per cent (dried substance).<\/p>\n

CHARACTERS<\/h2>\n

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

Solubility<\/h3>\nSoluble in water, practically insoluble in ethanol (96 per cent).<\/p>\n

IDENTIFICATION<\/h2>\nA. Solution S (see Tests) is slightly alkaline (2.2.4).<\/p>\nB. Loss on drying (see Tests).<\/p>\nC. Solution S gives reaction (b) of phosphates (2.3.1).<\/p>\nD. Solution S gives reaction (a) of sodium (2.3.1).<\/p>\n

TESTS<\/h2>\n

Solution S<\/h3>\nDissolve 5.0 g in distilled water R and dilute to 100.0 mL with the same solvent.<\/p>\n

Appearance of solution<\/h3>\nSolution S is clear (2.2.1) and colourless (2.2.2, Method II).<\/p>\n

Reducing substances<\/h3>\nTo 10 mL of solution S add 5 mL of dilute sulfuric acid R and 0.25 mL of a 3.2 g\/L solution of potassium permanganate R and heat on a water-bath for 5 min. The colour of the permanganate is not completely discharged.<\/p>\n

Monosodium phosphate<\/h3>\nMaximum 2.5 per cent.<\/p>\nFrom the volumes of 1 M sodium hydroxide (n1 mL, n2 mL and n3 mL) used in the assay, calculate the following ratio:<\/p>\nn2<\/sub>-n3<\/sub>\/n3<\/sub>-n1<\/sub><\/p>\nThis ratio is not greater than 0.025.<\/p>\n

Chlorides (2.4.4)<\/h3>\nMaximum 200 ppm.<\/p>\nDilute 5 mL of solution S to 15 mL with dilute nitric acid R.<\/p>\n

Sulfates (2.4.13)<\/h3>\nMaximum 500 ppm.<\/p>\nTo 6 mL of solution S add 2 mL of dilute hydrochloric acid R and dilute to 15 mL with distilled water R.<\/p>\n

Iron (2.4.9)<\/h3>\nMaximum 20 ppm, determined on solution S.<\/p>\n

Loss on drying (2.2.32)<\/h4>\nMaximum 1.0 per cent, determined on 1.000 g by drying in an oven at 105 \u00b0C for 4 h.<\/p>\n

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

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

Solubility<\/h3>\n
Soluble in water, practically insoluble in ethanol (96 per cent).<\/p>\n

IDENTIFICATION<\/h2>\n
A. Solution S (see Tests) is slightly alkaline (2.2.4).<\/p>\n
B. Loss on drying (see Tests).<\/p>\n
C. Solution S gives reaction (b) of phosphates (2.3.1).<\/p>\n
D. Solution S gives reaction (a) of sodium (2.3.1).<\/p>\n

Solution S<\/h3>\n
Dissolve 5.0 g in distilled water R and dilute to 100.0 mL with the same solvent.<\/p>\n

Appearance of solution<\/h3>\n
Solution S is clear (2.2.1) and colourless (2.2.2, Method II).<\/p>\n

Reducing substances<\/h3>\n
To 10 mL of solution S add 5 mL of dilute sulfuric acid R and 0.25 mL of a 3.2 g\/L solution of potassium permanganate R and heat on a water-bath for 5 min. The colour of the permanganate is not completely discharged.<\/p>\n

Monosodium phosphate<\/h3>\n
Maximum 2.5 per cent.<\/p>\n
From the volumes of 1 M sodium hydroxide (n1 mL, n2 mL and n3 mL) used in the assay, calculate the following ratio:<\/p>\n
n_{2<\/sub>-n_{3<\/sub>\/n_{3<\/sub>-n_{1<\/sub><\/p>\n}}}}
This ratio is not greater than 0.025.<\/p>\n

Chlorides (2.4.4)<\/h3>\n
Maximum 200 ppm.<\/p>\n
Dilute 5 mL of solution S to 15 mL with dilute nitric acid R.<\/p>\n

Sulfates (2.4.13)<\/h3>\n
Maximum 500 ppm.<\/p>\n
To 6 mL of solution S add 2 mL of dilute hydrochloric acid R and dilute to 15 mL with distilled water R.<\/p>\n

Iron (2.4.9)<\/h3>\n
Maximum 20 ppm, determined on solution S.<\/p>\n

Loss on drying (2.2.32)<\/h4>\n
Maximum 1.0 per cent, determined on 1.000 g by drying in an oven at 105 \u00b0C for 4 h.<\/p>\n