Calcium phosphate tribasic

In most chemical process industries, both qualitative and quantitative analyses are performed on many varieties of company products and the raw materials that go into these products. Some of the qualitative tests require a simple mixing of the test sample with a reagent to produce a color change. One such test can be run, for example, to confirm the contents of drums of tribasic calcium phosphate, which is a raw material for some pharmaceutical products. The test sample is dissolved in water, acidified, and then tested with a molybdate solution. A yellow precipitate indicates that the material is indeed tribasic calcium phosphate. 

Eric Niedergeses examines atesttube forthe presence of a yellow precipitate to confirm that the contents of a drum is tribasic calcium phosphate. Test tubes representing other drams are in the test tube rack on the bench in front of Eric. 

Tribasic Calcium Phosphate Dissolve 0.1 g in a mixture of 5 ml DW, 0.5 ml HC1 and 1 g citric acid. Dilute the solution to 40 ml with DW. Complies with the limit test for iron. 

Tribasic calcium phosphate occurs in nature as minerals, oxydapatite, whitlockite, voelicherite, apatite, phosphorite. It has many industrial applications. Some are similar to the monobasic and dibasic salts. It is used in fertilizers, dental products, ceramics and pohshing powder. Some other important applications are in plastics as a stabdizer as an anticaking agent as a nutrient supplement in cattle food for clarifying sugar syrup as a mordant in dyeing textiles and as a buffer to control pH. 

Tribasic calcium phosphate is obtained from naturally occurring minerals for fertilizer applications. The compound may be prepared in the laboratory by the reaction of sodium phosphate with calcium chloride with excess of ammonia. Also, it can be prepared by treatment of calcium hydroxide with phosphoric acid ... 

Calcium supplements Calcium carbonate (BioCal, Os-Cal 500, Turns, others) Calcium citrate (Citracal) Calcium glubionate (Calcionate, Neo-Calglucon) Calcium gluconate Calcium lactate Dibasic calcium phosphate Tribasic calcium phosphate (Posture) Provide an additional source of calcium to prevent calcium depletion and encourage bone formation in conditions such as osteoporosis, osteomalacia, rickets, and hypoparathyroidism... 

Sources of Phosphates.—The most available and most exploited sources of phosphorus and its compounds at the present day are the phosphatic rocks, or phosphorites, which consist of tribasic calcium phosphate associated with calcium carbonate, alumina, magnesia, etc.1 Phosphates of alumina are also useful. The production of these secondary rocks from the older rocks has already been mentioned (p. 208). Although the apatites themselves, as pure minerals, contain a high proportion of phosphoric anhydride, they are difficult to decompose, and are admixed with other minerals of a still more refractory nature. 

The Composition of Phosphorites.—Phosphoric anhydride, in the form of tribasic calcium phosphate, forms about 65 to 79 per... 

Tribasic calcium phosphate, Ca3P208, may be made by washing precipitated calcium phosphate with ammonia, which dissolves any excess of phosphoric acid above that required to form this compound. It is a white earthy powder which retains water tenaciously, and also adsorbs halides, bicarbonates and hydroxides.1 It has also been prepared from CaH4(P04)a by dissolving this in a large excess of water... 

The use of buffering agents in solid dose forms is not as widespread as the use in parenteral products. Nevertheless, the current Handbook of Pharmaceutical Excipients lists calcium carbonate, monobasic and dibasic sodium phosphate, sodium and potassium citrates, and tribasic calcium phosphate as potential buffering agents. ... 

Tribasic calcium phosphate is not a clearly defined chemical entity but is a mixture of calcium phosphates. Several chemical names, CAS Registry Numbers, and molecular formulas have therefore been used to describe this material. Those most frequently cited are shown below. 

The PhEur 2005 states that tribasic calcium phosphate consists of a mixture of calcium phosphates. It contains not less than 35.0% and not more than the equivalent of 40.0% of calcium. The USPNF 23 specifies that tribasic calcium phosphate consists of variable mixtures of calcium phosphates having the approximate composition 10CaO-3P2O5-H2O. This corresponds to a molecular formula of Ca5(0H)(P04)3 or Caio(OH)2(P04)s. 

Tribasic calcium phosphate is a white, odorless and tasteless powder. 

Table I Pharmacopeial specifications for tribasic calcium phosphate.

Tribasic calcium phosphate is widely used as a capsule diluent and tablet filler/binder in either direct-compression or wet-granulation processes. The primary bonding mechanism in compaction is plastic deformation. As with dibasic calcium phosphate, a lubricant and a disintegrant should usually be incorporated in capsule or tablet formulations that include tribasic calcium phosphate. In some cases tribasic calcium phosphate has been used as a disintegrant. It is most widely used in vitamin and mineral preparations as a filler and as a binder. It is a source of both calcium and phosphorus, the two main osteogenic minerals for bone health. The bioavailability of the calcium is well known to be improved by the presence of cholecalciferol. Recent research reports that combinations of tribasic calcium phosphate and vitamin D3 are a cost-effective advance in bone fracture prevention. ... 

In food applications, tribasic calcium phosphate powder is widely used as an anticaking agent. See Section 18. 

Moisture content slightly hygroscopic. A well-defined crystalline hydrate is not formed although surface moisture may be picked up or contained within small pores in the crystal structure. At relative humidities between about 15% and 65%, the equilibrium moisture content at 25°C is about 2.0%. At relative humidities above about 75%, tribasic calcium phosphate may absorb small amounts of moisture. Particle size distribution Tribasic calcium phosphate powder typical particle diameter 5-10 pm 98% of particles <44 pm. 

All calcium salts are incompatible with tetracycline antibiotics. Tribasic calcium phosphate is incompatible with tocopheryl acetate (but not tocopheryl succinate). Tribasic calcium phosphate may form sparingly soluble phosphates with hormones. 

Tribasic calcium phosphate occurs naturally as the minerals hydroxylapatite, voelicherite, and whitlockite. Commercially, it is prepared by treating phosphate-containing rock with sulfuric acid. Tribasic calcium phosphate powder is then precipitated by the addition of calcium hydroxide. Tribasic calcium phosphate is alternatively prepared by treating calcium hydroxide from limestone with purified phosphoric acid. It may also be obtained from calcined animal bones.Some tribasic calcium phosphate products may be prepared in coarser, directly compressible forms by granulating the powder using roller compaction or spray drying. 

Tribasic calcium phosphate is widely used in oral pharmaceutical formulations and food products and is generally regarded as nontoxic and nonirritant at the levels employed as a pharmaceutical excipient. 

Ingestion or inhalation of excessive quantities may result in the deposition of tribasic calcium phosphate crystals in tissues. These crystals may lead to inflammation and cause tissue lesions in the areas of deposition. 

Oral ingestion of very large quantities of tribasic calcium phosphate may cause abdominal discomfort such as nausea and vomiting. 

No teratogenic effects were found in chicken embryos exposed to a dose of 2.5 mg of tribasic calcium phosphate. ... 

One gram of tribasic calcium phosphate represents approximately 10.9 mmol of calcium and 6.4 mmol of phosphate 38% calcium and 17.3% phosphorus by weight. Tribasic calcium phosphate provides a higher calcium load than dibasic calcium phosphate and a higher Ca/P ratio. Granular and fine powder forms of tribasic calcium phosphate are available from various manufacturers. 

Chowhan ZT, Amaro AA. The effect of low- and high-humidity aging on the hardness, disintegration time and dissolution rate of tribasic calcium phosphate-based tablets. Drug Dev Ind Pharm 1979 5 545-562. 

Either bone phosphate (bone ash), obtained by heating bones to whiteness, or the mineral phosphorite is used as a source of tribasic calcium phosphate, which is the starting material in the industrial production of dibasic sodium phosphate. 

Tribasic calcium phosphate is finely ground and digested with sulfuric acid. This mixture is then leached with hot water and neutralized with sodium carbonate, and dibasic sodium phosphate is crystallized from the filtrate. 

Use of a support made of an alkaline earth metal compound [3 If]. Tribasic calcium phosphate, calcium carbonate, calcium fluoride, strontium titanate and magnesium aluminate are optimal supports. 

US patent 5,763,630 claims silver catalysts supported on other alkaline earth metal compounds than carbonates, such as calcium titanate, tribasic calcium phosphate, calcium molybdate, or calcium fluoride, as well as the magnesium and strontium analogues. Such supports provide significantly higher selectivity to the desired epoxide than would be expected from the performance of related materials. Selectivities are lower than those reported in the original Union Carbide patent. 

Tribasic calcium phosphate, Ca3(P04)2, may be called calcium orthophosphate, tricalcium orthophosphate, tertiary calcium orthophosphate, or tricalcium phosphate. Unlike the other two forms, the tribasic form contains no hydrogen atoms. 

Tribasic calcium phosphate can be obtained directly from rock and minerals such as apatite, a complex and impure form of calcium phosphate, or phosphorite, a mineral that... 

---