Aluminum hydroxide is a chemical compound that occurs naturally in various minerals. It has the molecular formula Al (OH) 3. Aluminum hydroxide is used in gastroenterology, nephrology, and immunology.
What is aluminum hydroxide?
Aluminum hydroxide is used in gastroenterology, immunology and nephrology, for example in dialysis patients. Aluminum hydroxide belongs to the aluminum compounds of the hydroxide chemical group. Several modifications of Al(OH)3 are known. These include the monoclinic modification, also commonly known under the name of the mineral gibbsite. Furthermore there is the hexagonal (mineral Bayerite) and triclinic (mineral Nordstrandite) modification. In addition, a more water-poor variant is known, the aluminum metahydroxide. It exists in the variants of the mineral diaspor or the mineral boehmite in orthorhombic form (crystal system). In the aluminum ore bauxite, the aluminum minerals gibbsite and boehmite occur in natural form. The chemical compound aluminum hydroxide has an amphoteric character. When it reacts with bases, it develops aluminates. With acids, however, aluminum hydroxide reacts to form aluminum salt solutions. The reaction rate of the aluminum hydroxide depends on the modifications involved. The solubility in acid is correspondingly higher possible. Aluminum hydroxide is not soluble in water. A white substance that is not flammable.
Pharmacological effect
As a component of basic substances, aluminum hydroxide is used in gastroenterology to neutralize gastric acid. It has a stool-clogging effect on the intestine. Therefore, it is often used in combination with magnesium carbonate or magnesium hydroxide, as these substances have the effect of a laxative. Aluminum hydroxide acts as an acid inhibitor. It reacts with stomach acid to form soluble complexes. Mixing with magnesium hydroxide also results in prolonged acid inhibition. The combination of these hydroxides is used when discomfort is caused by excess acid in the stomach. For example, in cases of heartburn or stomach ulcers. Furthermore, aluminum hydroxide is used when the kidneys are diseased. For dialysis patients it is used as a phosphate binder. Aluminum hydroxide eliminates phosphate from blood plasma very effectively. However, with long-term use, aluminum hydroxide has negative effects on bone metabolism and brain chemistry. Therefore, it is only used in the short term when phosphate levels are too high. Aluminum hydroxide also finds a use in immunology. It serves as an adjuvant that can enhance a vaccine’s mode of action. Aluminum hydroxide prevents precipitation, in which the vaccine proteins precipitate in a solution and appear as a solid precipitate. Thus, attachment to the ampoule wall is avoided. The vaccine can be stored for a correspondingly longer time. Then, after vaccination, aluminum hydroxide delays the effect as a depot. It causes an increased effect of the immune defense at the injection site. In addition, aluminum hydroxide also has industrial significance. It is the most important mineral fire retardant in the world.
Medical application and use
In medicine, various aluminum compounds, including aluminum hydroxide, are used to neutralize stomach acid. It always works in combination, as an appropriate aid. Aluminum hydroxide is also used for dialysis patients because it binds phosphate. Phosphate cannot be eliminated through the urine if kidney function is correspondingly impaired. However, it is absorbed with food and is therefore removed by means of aluminum hydroxide. According to some studies, aluminum hydroxide has a bad effect on other parts of the body’s metabolism after a few weeks of ingestion. Therefore, treatment with aluminum hydroxide remains limited to a maximum of 4 weeks. For vaccines, aluminum hydroxide is now rarely used. It is used in licensed vaccines in amounts ranging from 0.2 to 2.4 mg. Thus, the amount used is significantly lower than in many foods. In the dosages used, aluminum hydroxide is not toxic. It causes only local tissue irritation during vaccination. Instead of aluminum hydroxide, a newer adjuvant, such as squalene, is often used. It is also an effect enhancer for vaccines. However, effect enhancers for vaccines are generally disputed by vaccination opponents.Aluminum hydroxide clearly helps to reduce the number of vaccinations because it increases the mode of action of the single vaccination accordingly.
Risks and side effects
Aluminum hydroxide can cause harmful side effects in vaccines accordingly. It is a variety of inflammation of muscle connective tissue, also called macrophagic myofasciitis. It occurs in the vicinity of vaccination sites.
