What are the scientific and common names for dicalcium phosphate dihydrate?
While the systematic chemical name is dicalcium phosphate dihydrate, this compound is known by several other important names depending on the context. The most common alternative name is brushite, which refers to its mineral form found in nature. Other chemical names include dibasic calcium phosphate dihydrate and calcium hydrogen phosphate dihydrate. The prefix "dibasic" comes from the fact that two protons were removed from phosphoric acid to form the hydrogen phosphate anion ($HPO_4^{2-}$). Knowing these different names is crucial for researchers, manufacturers, and consumers who encounter this compound in various products.
Origins of brushite
Brushite was first described in 1865 after its discovery on Aves Island, Venezuela, and was named in honor of the American mineralogist George Jarvis Brush. It is believed to be a precursor mineral to apatite and is found in environments rich in guano, where the organic material interacts with calcium-rich sources like clay and calcite. Its formation in these conditions occurs at a slightly acidic pH, making it distinct from more stable calcium phosphate minerals that form in alkaline conditions. The crystals of brushite can be colorless to pale yellow and often appear as small, prismatic or tabular formations.
Uses of dicalcium phosphate dihydrate (brushite)
Dietary and pharmaceutical applications
Dicalcium phosphate dihydrate is a widely used ingredient in the food and pharmaceutical industries due to its dual mineral content of calcium and phosphorus. It is often found in dietary supplements to help meet the body's needs for bone and dental health. In the pharmaceutical sector, it serves as a tableting agent, acting as a binder and diluent in tablet and capsule formulations.
- Dietary Supplements: It provides a bioavailable source of calcium and phosphorus in multivitamin and mineral supplements.
- Food Additive: Acts as a leavening agent in baked goods and as a mineral fortifier in products like enriched flour and cereals.
- Animal Feed: Extensively used as a mineral supplement for livestock and poultry to support bone development and overall health.
Oral and dental care
One of the most common applications of dicalcium phosphate dihydrate is in oral hygiene products. It acts as a mild abrasive and polishing agent in toothpaste, helping to remove plaque and surface stains from teeth without being overly harsh on enamel. This mechanical action, combined with its mineral content, makes it a valuable component in maintaining dental hygiene.
Biomaterials and bone regeneration
Brushite's unique properties, including its biocompatibility and biodegradability, make it a significant material in bone tissue engineering. It is often used as a component in bone cements and bioceramics, providing a scaffold for new bone tissue growth. Due to its slightly acidic nature, it is more readily resorbed by the body compared to other calcium phosphates like hydroxyapatite.
Comparison of dicalcium phosphate dihydrate with other calcium phosphates
| Feature | Dicalcium Phosphate Dihydrate (Brushite) | Dicalcium Phosphate Anhydrous (Monetite) | Tricalcium Phosphate ($Ca_3(PO_4)_2$) |
|---|---|---|---|
| Chemical Formula | $CaHPO_4·2H_2O$ | $CaHPO_4$ | $Ca_3(PO_4)_2$ |
| Mineral Name | Brushite | Monetite | Whitlockite, among others |
| Hydration State | Hydrated (contains water) | Anhydrous (water-free) | Anhydrous |
| Stability in Water | Less stable, can convert to hydroxyapatite over time | More stable than the dihydrate form | Relatively stable, less soluble |
| Common Uses | Dietary supplements, pharmaceuticals, bone cements | Tableting agent, abrasive in toothpaste | Food additive, bone grafting material |
Brushite's role in health and disease
Despite its beneficial uses, brushite also has a notable role in pathology. It is one of the primary components of calcium phosphate kidney stones. These stones often form in a slightly acidic urinary environment and can be difficult to treat due to their composition. Furthermore, brushite is also a common mineral found in dental calculus, or tartar, which is a hardened plaque that forms on teeth. This dual nature highlights the complex role of calcium phosphates in biological systems.
Conclusion: The many facets of dicalcium phosphate dihydrate
In summary, dicalcium phosphate dihydrate is a versatile compound with a variety of names, including its mineral form, brushite, and its chemical designation, dibasic calcium phosphate dihydrate. Its applications are widespread, ranging from serving as a crucial source of minerals in dietary supplements and animal feed to acting as an excipient in pharmaceutical tablets. Moreover, it plays an important role in biomaterials for bone regeneration and as an abrasive in oral care products. Conversely, its presence in pathological formations like kidney stones and dental calculus underscores its complex biological impact. Understanding these different names and applications is key to appreciating the compound's significance across various scientific and industrial fields.
