{"id":12929,"date":"2025-10-11T16:44:13","date_gmt":"2025-10-11T09:44:13","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=12929"},"modified":"2025-11-15T15:15:32","modified_gmt":"2025-11-15T08:15:32","slug":"disodium-hydrogen-phosphate-dihydrate","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/disodium-hydrogen-phosphate-dihydrate\/","title":{"rendered":"Disodium Hydrogen Phosphate Dihydrate"},"content":{"rendered":"

Sodium Phosphate Dihydrate<\/p>\n

(Disodium Phosphate Dihydrate, Ph. Eur. monograph 0602)<\/em><\/p>\n

Na_{2<\/sub>HPO_{4<\/sub>,2H_{2<\/sub>O\u00a0 178.0\u00a0 10028-24-7<\/p>\n}}}

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

Excipient.<\/p>\n

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

Phosphates Enema<\/p>\n

Phosphate Oral Solution<\/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 or colourless crystals.<\/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 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 5 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 (n_{1<\/sub> mL, n_{2<\/sub> mL and n_{3<\/sub> 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 400 ppm.<\/p>\n
To 2.5 mL of solution S add 10 mL of dilute nitric acid R and dilute to 15 mL with water R.<\/p>\n
Sulfates (2.4.13)<\/h3>\n
Maximum 0.1 per cent.<\/p>\n
To 3 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 40 ppm.<\/p>\n
Dilute 5 mL of solution S to 10 mL with water R.<\/p>\n
Loss on drying (2.2.32)<\/h3>\n
19.5 per cent to 21.0 per cent, determined on 1.000 g by drying in an oven at 130 \u00b0C.<\/p>\n
ASSAY<\/h2>\n
Dissolve 2.000 g (m) in 50 mL of 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 (n_{1<\/sub> mL). Continue the titration to the 2 inflexion point (total volume of 1 M sodium hydroxide required, n_{2<\/sub> mL). Carry out a blank titration (n_{3<\/sub> 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","protected":false},"excerpt":{"rendered":"
Sodium Phosphate Dihydrate (Disodium Phosphate Dihydrate, Ph. Eur. monograph 0602) Na2HPO4,2H2O\u00a0 178.0\u00a0 10028-24-7 Action and use Excipient. Preparations Phosphates Enema Phosphate Oral Solution DEFINITION Content 98.0 per cent to 101.0 per cent (dried substance). CHARACTERS Appearance White or almost white powder or colourless crystals. Solubility Soluble in water, practically insoluble in ethanol (96 per cent)….<\/p>\n","protected":false},"author":4,"featured_media":12937,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-12929","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-volumes-1-2"],"acf":[],"_links":{"self":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/12929","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\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=12929"}],"version-history":[{"count":3,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/12929\/revisions"}],"predecessor-version":[{"id":12939,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/12929\/revisions\/12939"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/12937"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=12929"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=12929"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=12929"}],"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 or colourless crystals.<\/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 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 5 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

Chlorides (2.4.4)<\/h3>\nMaximum 400 ppm.<\/p>\nTo 2.5 mL of solution S add 10 mL of dilute nitric acid R and dilute to 15 mL with water R.<\/p>\n

Sulfates (2.4.13)<\/h3>\nMaximum 0.1 per cent.<\/p>\nTo 3 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 40 ppm.<\/p>\nDilute 5 mL of solution S to 10 mL with water R.<\/p>\n

Loss on drying (2.2.32)<\/h3>\n19.5 per cent to 21.0 per cent, determined on 1.000 g by drying in an oven at 130 \u00b0C.<\/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 or colourless crystals.<\/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 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 5 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

Chlorides (2.4.4)<\/h3>\n
Maximum 400 ppm.<\/p>\n
To 2.5 mL of solution S add 10 mL of dilute nitric acid R and dilute to 15 mL with water R.<\/p>\n

Sulfates (2.4.13)<\/h3>\n
Maximum 0.1 per cent.<\/p>\n
To 3 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 40 ppm.<\/p>\n
Dilute 5 mL of solution S to 10 mL with water R.<\/p>\n

Loss on drying (2.2.32)<\/h3>\n
19.5 per cent to 21.0 per cent, determined on 1.000 g by drying in an oven at 130 \u00b0C.<\/p>\n