{"id":15915,"date":"2025-10-18T11:53:57","date_gmt":"2025-10-18T04:53:57","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=15915"},"modified":"2025-11-15T15:54:27","modified_gmt":"2025-11-15T08:54:27","slug":"hydrated-aluminium-hydroxide-for-adsorption","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/hydrated-aluminium-hydroxide-for-adsorption\/","title":{"rendered":"Hydrated Aluminium Hydroxide for Adsorption"},"content":{"rendered":"

(Ph. Eur. monograph 1664)<\/p>\n[AlO(OH)],xH2<\/sub>O<\/p>\n

DEFINITION<\/h2>\n

Content<\/h3>\n

90.0 per cent to 110.0 per cent of the content of aluminium stated on the label.<\/p>\n

NOTE: shake the gel vigorously for at least 30 s immediately before examining.<\/p>\n

CHARACTERS<\/h2>\n

Appearance<\/h3>\n

White or almost white, translucent, viscous, colloidal gel. A supernatant may be formed upon standing.<\/p>\n

Solubility<\/h3>\n

A clear or almost clear solution is obtained with alkali hydroxide solutions and mineral acids.<\/p>\n

IDENTIFICATION<\/h2>\n

Solution S (see Tests) gives the reaction of aluminium.<\/p>\n

To 10 mL of solution S add about 0.5 mL of dilute hydrochloric acid R and about 0.5 mL of thioacetamide reagent R. No precipitate is formed. Add dropwise 5 mL of dilute sodium hydroxide solution R. Allow to stand for 1 h. A gelatinous white precipitate is formed which dissolves upon addition of 5 mL of dilute sodium hydroxide solution R. Gradually add 5 mL of ammonium chloride solution R and allow to stand for 30 min. The gelatinous white precipitate is re-formed.<\/p>\n

TESTS<\/h2>\n

Solution S<\/h3>\n

Add 1 g to 4 mL of hydrochloric acid R. Heat at 60 \u00b0C for 1 h, cool, dilute to 50 mL with distilled water R and filter if necessary.<\/p>\n

pH (2.2.3)<\/h3>\n

5.5 to 8.5.<\/p>\n

Adsorption power<\/h3>\n

Dilute the substance to be examined with distilled water R to obtain an aluminium concentration of 5 mg\/mL. Prepare bovine albumin R solutions with the following concentrations of bovine albumin: 0.5 mg\/mL, 1 mg\/mL, 2 mg\/mL, 3 mg\/mL, 5 mg\/mL and 10 mg\/mL. If necessary, adjust the gel and the bovine albumin R solutions to pH 6.0 with dilute hydrochloric acid R or dilute sodium hydroxide solution R.<\/p>\n

For adsorption, mix 1 part of the diluted gel with 4 parts of each of the solutions of bovine albumin R and allow to stand at room temperature for 1 h.<\/p>\n

During this time shake the mixture vigorously at least 5 times. Centrifuge or filter through a non- protein-retaining filter. Immediately determine the protein content (2.5.33, Method 2) of either the supernatant or the filtrate.<\/p>\n

It complies with the test if no bovine albumin is detectable in the supernatant or filtrate of the 2 mg\/mL bovine albumin R solution (maximum level of adsorption) and in the supernatant or filtrate of bovine albumin R solutions of lower concentrations. Solutions containing 3 mg\/mL, 5 mg\/mL and 10 mg\/mL bovine albumin R may show bovine albumin in the supernatant or filtrate, proportional to the amount of bovine albumin in the solutions.<\/p>\n

Sedimentation<\/h3>\n

If necessary, adjust the substance to be examined to pH 6.0 using dilute hydrochloric acid R or dilute sodium hydroxide solution R. Dilute with distilled water R to obtain an aluminium concentration of approximately 5 mg\/mL. If the aluminium content of the substance to be examined is lower than 5 mg\/mL, adjust to pH 6.0 and dilute with a 9 g\/L solution of sodium chloride R to obtain an aluminium concentration of about 1 mg\/mL. After shaking for at least 30 s, place 25 mL of the preparation in a 25 mL graduated cylinder and allow to stand for 24 h.<\/p>\n

It complies with the test if the volume of the clear supernatant is less than 5 mL for the gel with an aluminium content of about 5 mg\/mL.<\/p>\n

It complies with the test if the volume of the clear supernatant is less than 20 mL for the gel with an aluminium content of about 1 mg\/mL.<\/p>\n

Chlorides (2.4.4)<\/h3>\n

Maximum 0.33 per cent.<\/p>\n

Dissolve 0.5 g in 10 mL of dilute nitric acid R and dilute to 500 mL with water R.<\/p>\n

Nitrates<\/h3>\n

Maximum 100 ppm.<\/p>\n

Place 5 g in a test-tube immersed in ice-water, add 0.4 mL of a 100 g\/L solution of potassium chloride R, 0.1 mL of diphenylamine solution R and, dropwise with shaking, 5 mL of sulfuric acid R. Transfer the tube to a water-bath at 50 \u00b0C.<\/p>\n

After 15 min, any blue colour in the solution is not more intense than that in a standard prepared at the same time and in the same manner using 5 mL of nitrate standard solution (100 ppm NO3<\/sub>) R.<\/p>\n

Sulfates (2.4.13)<\/h3>\n

Maximum 0.5 per cent.<\/p>\n

Dilute 2 mL of solution S to 20 mL with water R.<\/p>\n

Ammonium (2.4.1, Method B)<\/h3>\n

Maximum 50 ppm, determined on 1.0 g.<\/p>\n

Prepare the standard using 0.5 mL of ammonium standard solution (100 ppm NH4) R.<\/p>\n

Arsenic (2.4.2, Method A)<\/h3>\n

Maximum 1 ppm, determined on 1 g.<\/p>\n

Iron (2.4.9)<\/h3>\n

Maximum 15 ppm, determined on 0.67 g.<\/p>\n

Bacterial endotoxins (2.6.14)<\/h3>\n

Less than 5 IU of endotoxin per milligram of aluminium, if intended for use in the manufacture of an adsorbed product without a further appropriate procedure for the removal of bacterial endotoxins.<\/p>\n

ASSAY<\/h2>\n

Dissolve 2.50 g in 10 mL of hydrochloric acid R, heating for 30 min at 100 \u00b0C on a water-bath. Cool and dilute to 20 mL with water R. To 10 mL of the solution, add concentrated ammonia R until a precipitate is obtained. Add the smallest quantity of hydrochloric acid R needed to dissolve the precipitate and dilute to 20 mL with water R. Carry out the complexometric titration of aluminium (2.5.11). Carry out a blank titration.<\/p>\n

STORAGE<\/h2>\n

At a temperature not exceeding 30 \u00b0C. Do not allow to freeze. If the substance is sterile, store in a sterile, airtight, tamper- evident container.<\/p>\n

LABELLING<\/h2>\n

The label states the declared content of aluminium.<\/p>\n","protected":false},"excerpt":{"rendered":"

(Ph. Eur. monograph 1664) [AlO(OH)],xH2O DEFINITION Content 90.0 per cent to 110.0 per cent of the content of aluminium stated on the label. NOTE: shake the gel vigorously for at least 30 s immediately before examining. CHARACTERS Appearance White or almost white, translucent, viscous, colloidal gel. A supernatant may be formed upon standing. Solubility A…<\/p>\n","protected":false},"author":4,"featured_media":15918,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-15915","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\/15915","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=15915"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/15915\/revisions"}],"predecessor-version":[{"id":15920,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/15915\/revisions\/15920"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/15918"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=15915"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=15915"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=15915"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}