Major Research Findings

Aluminum hydroxide has been studied for its various effects in different fields. 6 found that aluminum hydroxide can improve the fire resistance of asphalt. By adding aluminum hydroxide to asphalt, the thermal decomposition temperature during combustion increases, and the amount of smoke generated decreases. This is thought to be because aluminum hydroxide generates water when it burns, absorbing heat and suppressing combustion.

On the other hand, 16 suggests that aluminum hydroxide, used as a vaccine adjuvant, may cause histological changes in the liver, lungs, heart, and kidneys of neonatal mice. While this study showed that the effects of aluminum hydroxide nanoparticles are smaller than those of conventional aluminum hydroxide, tissue effects were still observed. Aluminum hydroxide nanoparticles may be more likely to pass through cell membranes than conventional particles and enter cells. Therefore, further research is needed on the safety of aluminum hydroxide nanoparticles.

discovered that antacids containing aluminum hydroxide can affect bowel evacuation. The research suggests that aluminum hydroxide may cause constipation. This is thought to be because aluminum hydroxide absorbs water in the intestines, making stools harder.

13 demonstrated that aluminum hydroxide does not affect the pharmacokinetics of temazepam. Temazepam is a drug used as a sleeping pill, but its absorption and excretion were not affected by the combined use with aluminum hydroxide.

18 investigated the mechanism of action of polymers used to increase the dispersibility of aluminum hydroxide. The study revealed that the type and structure of the polymer significantly affect the dispersibility of aluminum hydroxide. By using suitable polymers, it is possible to prevent the aggregation of aluminum hydroxide and improve its dispersibility.

8 studied the thermal stability of proteins immobilized on aluminum hydroxide. The study concluded that immobilizing proteins on aluminum hydroxide does not significantly affect their thermal stability. However, the adsorption rate and crowding of proteins on aluminum hydroxide particles have a significant impact on protein aggregation behavior, the hydrogen bond strength of intermolecular β-sheet aggregates, and the conformation of intermediate states.

19 examined the influence of nickel ions on the formation and transformation of aluminum hydroxide sediment. The research found that the presence of nickel ions promotes the formation of bayerite. Particularly, when the molar ratio of nickel ions to aluminum ions is high, the formation of aluminum hydroxide sediment is suppressed, and nickel aluminum oxide is produced instead.

12 investigated the effects of omeprazole and aluminum hydroxide/magnesium hydroxide on the absorption of riociguat. The study discovered that both omeprazole and aluminum hydroxide/magnesium hydroxide inhibit the absorption of riociguat. Riociguat is a drug used to treat pulmonary hypertension, but its combined use with these drugs may reduce its effectiveness.

demonstrated that aluminum hydroxide enhances the immunogenicity of vaccines, such as inactivated polio vaccines. By adding aluminum hydroxide to vaccines, it is possible to strengthen the immune response and increase the effectiveness of the vaccine.

14 found that antacids containing aluminum hydroxide inhibit the absorption of ciprofloxacin, an antibiotic. The study indicated that taking antacids containing aluminum hydroxide simultaneously with ciprofloxacin may lower the blood concentration of ciprofloxacin and weaken its effectiveness.

studied the effects of aluminum hydroxide on the levels of PGE2 in the stomach and duodenum. PGE2 is a hormone that protects the digestive tract. The study showed that aluminum hydroxide may reduce the amount of PGE2. Therefore, long-term consumption of aluminum hydroxide may weaken the protective effect on the digestive tract.

4 investigated the effects of aluminum hydroxide on the parathyroid-vitamin D axis in postmenopausal women. The study revealed that aluminum hydroxide inhibits the absorption of phosphorus from the intestines, reducing the phosphorus level in the blood. When the phosphorus level in the blood decreases, parathyroid hormone secretion is stimulated, and the production of calcitriol, the active form of vitamin D, increases.

3 showed that hollow silica nanoparticles containing aluminum hydroxide, when used as a carrier for anticancer drugs and tumor antigens, enhance immunotherapy effects. This study demonstrated that silica nanoparticles containing aluminum hydroxide effectively deliver anticancer drugs to tumor cells and activate immune cells. Furthermore, these nanoparticles were shown to induce immunogenic cell death in tumor cells, strengthening the anti-tumor immune response.

15 found that antacids containing aluminum hydroxide inhibit the absorption of rufloxacin. Rufloxacin is a drug used to treat bacterial infections, but this study showed that taking antacids containing aluminum hydroxide simultaneously with rufloxacin may lower the blood concentration of rufloxacin and weaken its effectiveness.

10 revealed that aluminum hydroxide affects the absorption of aspirin. The study demonstrated that aluminum hydroxide slows the absorption rate of aspirin, weakening its effect. However, aluminum hydroxide did not affect the amount of aspirin absorbed.

7 examined the effects of replacing aluminum hydroxide with calcium carbonate in hemodialysis patients. The study showed that substituting calcium carbonate for aluminum hydroxide improved metabolic acidosis, parathyroid function, and blood calcium concentration. The study suggests that aluminum hydroxide may increase blood aluminum levels in hemodialysis patients, leading to metabolic acidosis and decreased parathyroid function.

9 demonstrated that adding aluminum hydroxide to vaccines can improve vaccine effectiveness in ASC (apoptosis-associated speck-like protein) deficient mice. ASC is a protein that plays a crucial role in the activation of inflammasomes, which are immune cells. The study showed that ASC-deficient mice have a weak immune response to vaccines and have a lower protective effect from vaccines. However, adding aluminum hydroxide to vaccines strengthened the immune response and improved the protective effect in ASC-deficient mice as well. This is thought to be because aluminum hydroxide can activate inflammasomes even in ASC-deficient mice.

1 investigated the effects of antacids containing aluminum hydroxide on the absorption of ofloxacin. The study found that antacids containing aluminum hydroxide slightly inhibit the absorption of ofloxacin. However, this inhibitory effect was hardly observed when the antacid was taken more than two hours before ofloxacin.

11 studied the effects of aluminum hydroxide on fluoride and calcium metabolism. The study revealed that the intake of aluminum hydroxide increases fecal fluoride excretion and reduces fluoride absorption. Additionally, aluminum hydroxide intake resulted in phosphorus depletion, increased urinary calcium excretion, and a negative calcium balance.

17 investigated the effects of lipid A and aluminum hydroxide on the immunogenicity of protein and peptide antigens encapsulated in liposomes. The study showed that both lipid A and aluminum hydroxide enhance the immune response to antigens encapsulated in liposomes.

5 examined the effects of co-adsorption of ALF (Army Liposome Formulation) or ALFQ (Army Liposome Formulation + QS21) to the aluminum-antigen complex. This research showed that co-adsorbing ALF or ALFQ significantly enhances the immune response to antigens adsorbed on aluminum hydroxide. Notably, ALF primarily induces a Th2-type response, while ALFQ and ALFQA induce more balanced Th1/Th2 responses.

2 studied the effects of aluminum hydroxide and famotidine on the bioavailability of tosufloxacin. The study found that coadministration of aluminum hydroxide reduces the bioavailability of tosufloxacin. Famotidine did not alter tosufloxacin absorption. To prevent potential treatment failures, concurrent use of tosufloxacin and aluminum hydroxide should be avoided altogether.

Benefits and Risks

Benefit Summary

Aluminum hydroxide has potential benefits in improving the fire resistance of asphalt and enhancing the immunogenicity of vaccines. Moreover, aluminum hydroxide nanoparticles have greater cellular penetration compared to conventional particles, making them promising candidates for developing new types of vaccines and pharmaceuticals. However, aluminum hydroxide also comes with some risks, including inhibiting bowel evacuation, blocking the absorption of specific medications, and affecting the metabolism of fluoride and calcium. The risks associated with aluminum hydroxide should be considered when using it.

Risk Summary

Aluminum hydroxide has reported risks, including constipation, inhibition of the absorption of specific drugs, and potential effects on the metabolism of fluoride and calcium. Additionally, aluminum hydroxide nanoparticles raise safety concerns due to their enhanced cellular penetration.

Comparison Between Studies

Commonalities

Several studies indicate that aluminum hydroxide affects the properties of various substances. Notably, a common finding across these studies is that aluminum hydroxide alters the surface characteristics and reactivity of substances.

Differences

The effects of aluminum hydroxide vary depending on its form, particle size, dosage, and target substance. Therefore, the findings of each study may not always align with those of other studies. It is important to note that the specific context and conditions of each study influence the observed effects.

Consistency and Contradictions in Results

Research on the effects of aluminum hydroxide has reported both consistent and contradictory findings. This variability stems from the fact that the effects of aluminum hydroxide are highly dependent on its form, particle size, dosage, and the target substance. Furthermore, differences in research methodologies and experimental conditions can also lead to varying results. Therefore, further research is crucial for a more comprehensive understanding of the effects of aluminum hydroxide.

Precautions for Application in Daily Life

Aluminum hydroxide is present in various aspects of our daily lives, such as antacids, vaccines, and food additives. Although aluminum hydroxide is generally considered safe, it comes with certain risks. When consuming aluminum hydroxide, it is important to be aware of these risks and avoid excessive intake. Additionally, when using products containing aluminum hydroxide, it is crucial to carefully review the product information and follow the appropriate instructions for use.

Limitations of Current Research

Research on aluminum hydroxide is still insufficient, particularly regarding the safety of aluminum hydroxide nanoparticles. Despite the importance of this topic, research in this area is inadequate. Additionally, the long-term effects of aluminum hydroxide on the human body are yet to be fully understood. Further research is necessary to address these challenges.

Future Research Directions

Future research on aluminum hydroxide should focus on the following areas:

• Safety studies on aluminum hydroxide nanoparticles
• Research on the long-term effects of aluminum hydroxide on the human body
• Studies on the pharmacokinetics of aluminum hydroxide
• Research on the environmental impact of aluminum hydroxide

Conclusion

Aluminum hydroxide is a widely used substance in various fields, but its effects are highly dependent on its form, particle size, dosage, and the target substance. It is crucial to understand the risks associated with aluminum hydroxide and use it appropriately. Furthermore, additional research is needed to investigate the safety and environmental impact of aluminum hydroxide.