Name: Aluminum Oxide
CAS No: Aluminum oxide [1344-28-1]
None adopted.
Activated alumina; activated aluminum oxide; alpha aluminum oxide; alumina; alumina, calcined; alumina, tabular; aluminum oxide alumite; aluminum trioxide; gamma aluminum oxide
Aluminum oxide [1344-28-1]
Al2O3 101.96
Aluminum oxide occurs naturally as the minerals bauxite, bayerite, boehmite, corundum, diaspore, and gibbsite.
Aluminum oxide is used mainly in tablet formulations.(1) It is used for decoloring powders and is particularly widely used in antibiotic formulations. It is also used in suppositories, pessaries, and urethral inserts. Hydrated aluminum oxide (see Section 18) is used in mordant dyeing to make lake pigments, in cosmetics, and therapeutically as an antacid.
Aluminum oxide occurs as a white crystalline powder. Aluminum oxide occurs as two crystalline forms: a-aluminum oxide is composed of colorless hexagonal crystals, and g-aluminum oxide is composed of minute colorless cubic crystals that are transformed to the a-form at high temperatures.
See Section 18.
Boiling point 29778C Density (bulk) 0.91.1 g/cm3 Flammability Nonflammable. Hardness (Mohs) 8.8 Hygroscopicity Very hygroscopic. Melting point 20508C Solubility Slowly soluble in aqueous alkaline solutions with the formation of hydroxides; practically insoluble in nonpolar organic solvents, diethyl ether, ethanol (95%), and water. Specific gravity 2.8 (becomes 4.0 at 8008C) Vapor pressure 133.3 Pa at 21588C
Aluminum oxide should be stored in a well-closed container in a cool, dry, place. It is very hygroscopic.
Aluminum oxide should be kept well away from water. It is incompatible with strong oxidizers and chlorinated rubber. Aluminum oxide also reacts with chlorine trifluoride, ethylene oxide, sodium nitrate, and vinyl acetate. Exothermic reactions above 2008C with halocarbon vapors produce toxic hydrogen chloride and phosgene fumes.
Most of the aluminum oxide produced commercially is obtained by the calcination of aluminum hydroxide.
Aluminum oxide is generally regarded as relatively nontoxic and nonirritant when used as an excipient. Inhalation of finely divided particles may cause lung damage (Shaver’s disease).(2
Observe normal precautions appropriate to the circumstances and quantity of the material handled.(3) In the UK, the workplace exposure limits for aluminum oxide are 10 mg/m3 long-term (8- hour TWA) for total inhalable dust and 4 mg/m3 for respirable dust.(4) In the USA, the OSHA limit is 15 mg/m3 total dust, 5 mg/m3 respirable fraction for aluminium oxide.(5)
Included in the FDA Inactive Ingredients Database (oral tablets and topical sponge). Included in nonparenteral medicines licensed in the UK.
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A specification for aluminum oxide is included in the Japanese Pharmaceutical Excipients (JPE);(6) see Table I. A specification for light aluminum oxide is also included. The PhEur 6.3 includes a specification for hydrated aluminum oxide that contains the equivalent of 47.0–60.0% of Al2O3. The EINECS number for aluminum oxide is 215-691-6.