Tricalcium phosphate

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Tricalcium phosphate
Tricalcium phosphate.svg
CAS number 7758-87-4 YesY
PubChem 516943
ChemSpider 22864 YesY
UNII K4C08XP666 YesY
ATC code A12AA01
Jmol-3D images Image 1
Molecular formula Ca3O8P2
Molar mass 310.18 g mol−1
Appearance White amorphous powder
Density 3.14 g/cm3
Melting point Liquifies under high pressure at 1670 K (1391 °C)
Solubility in water 0.002 g/100 g
-4126 kcal/mol (α-form)[1]
EU Index Not listed
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point Non-flammable
Related compounds
Other anions Calcium pyrophosphate
Other cations Trimagnesium phosphate
Trisodium phosphate
Tripotassium phosphate
Related compounds Monocalcium phosphate
Dicalcium phosphate
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references

Tricalcium phosphate (sometimes abbreviated TCP) is a calcium salt of phosphoric acid with the chemical formula Ca3(PO4)2. It is also known as tribasic calcium phosphate and bone phosphate of lime (BPL). Calcium phosphate is one of the main combustion products of bone (see bone ash). Calcium phosphate is also commonly derived from inorganic sources such as mineral rock.[2]

It has an alpha and a beta crystal form, the alpha state being formed at high temperatures. As rock, it is found in Whitlockite.


Main article: Calcium phosphate

Calcium phosphate refers to minerals containing calcium ions (Ca2+) together with orthophosphates (PO43−), metaphosphates or pyrophosphates (P2O74−) and occasionally hydrogen or hydroxide ions. Especially, the common mineral apatite has formula Ca5(PO4)3X, where X is F, Cl, OH, or a mixture; it is hydroxyapatite if the extra ion is mainly hydroxide. Much of the "tricalcium phosphate" on the market is actually powdered hydroxyapatite.

Natural occurrence[edit]

Tricalcium phosphate occurs naturally in several forms, including:

  • as a rock in Morocco, Israel, Philippines, Egypt, and Kola (Russia) and in smaller quantities in some other countries. The natural form is not completely pure, and there are some other components like sand and lime which can change the composition. In terms of P2O5, most calcium phosphate rocks have a content of 30% to 40% P2O5 in weight.
  • in the skeletons and teeth of vertebrate animals
  • in cow's milk.


Tricalcium phosphate is used in powdered spices as an anticaking agent. It is also found in baby powder.

Calcium phosphate is an important raw material for the production of phosphoric acid and fertilizers, for example in the Odda process. Phosphate ore quality and quantity is often specified as percent BPL (bone phosphate of lime), where 1% BPL is equivalent to 0.458% P2O5.[3]

Calcium phosphate is also a raising agent (food additive) E341. As a mineral salt found in rocks and bones, it is used in cheese products.

It is also used as a nutritional supplement[4] and occurs naturally in cow milk[citation needed], although the most common and economical forms for supplementation are calcium carbonate (which should be taken with food) and calcium citrate (which can be taken without food).[5] There is some debate about the different bioavailabilities of the different calcium salts.

It is commonly used in porcelain and dental powders, and medically as an antacid or calcium supplement, although calcium carbonate is more common in this regard.

It can be used as a tissue replacement for repairing bony defects when autogenous bone graft is not feasible or possible.[6][7][8] It may be used alone or in combination with a biodegradable, resorbable polymer such as polyglycolic acid.[9] It may also be combined with autologous materials for a bone graft.[10][11]

Porous beta-Tricalcium phosphate scaffolds are employed as drug carrier systems for local drug delivery in bone.[12]

Another practical application of the compound is its use in gene transfection. The calcium ions can make a cell competent to allow exogenous genes to enter the cell by diffusion. A heat shock afterwards then invokes the cell to repair itself. This is a quick and easy method for transfection, albeit a rather inefficient one.

Calcium triphosphate is used to remove fluoride from water in water filtration systems.[13]


  1. ^ Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A21. ISBN 0-618-94690-X. 
  2. ^ Yacoubou, Jeanne, MS. Vegetarian Journal's Guide To Food Ingredients “Guide to Food Ingredients”. The Vegetarian Resource Group, n.d. Web. 14 Sept. 2012.
  3. ^ Ober, JA, Phosphate Rock: U.S. Geological Survey Mineral Information 
  4. ^ Bonjour JP, Carrie AL, Ferrari S, Clavien H, Slosman D, Theintz G, Rizzoli R (March 1997). "Calcium-enriched foods and bone mass growth in prepubertal girls: a randomized, double-blind, placebo-controlled trial". J. Clin. Invest. 99 (6): 1287–94. doi:10.1172/JCI119287. PMC 507944. PMID 9077538. 
  5. ^ Straub DA (June 2007). "Calcium supplementation in clinical practice: a review of forms, doses, and indications". Nutr Clin Pract 22 (3): 286–96. doi:10.1177/0115426507022003286. PMID 17507729. 
  6. ^ Paderni S, Terzi S, Amendola L (September 2009). "Major bone defect treatment with an osteoconductive bone substitute". Musculoskelet Surg 93 (2): 89–96. doi:10.1007/s12306-009-0028-0. PMID 19711008. 
  7. ^ Moore DC, Chapman MW, Manske D (1987). "The evaluation of a biphasic calcium phosphate ceramic for use in grafting long-bone diaphyseal defects". Journal of Orthopaedic Research 5 (3): 356–65. doi:10.1002/jor.1100050307. PMID 3040949. 
  8. ^ Lange TA, Zerwekh JE, Peek RD, Mooney V, Harrison BH (1986). "Granular tricalcium phosphate in large cancellous defects". Annals of Clinical and Laboratory Science 16 (6): 467–72. PMID 3541772. 
  9. ^ Cao H, Kuboyama N (September 2009). "A biodegradable porous composite scaffold of PGA/beta-TCP for bone tissue engineering". Bone 46 (2): 386–95. doi:10.1016/j.bone.2009.09.031. PMID 19800045. 
  10. ^ Erbe EM, Marx JG, Clineff TD, Bellincampi LD (October 2001). "Potential of an ultraporous beta-tricalcium phosphate synthetic cancellous bone void filler and bone marrow aspirate composite graft". European Spine Journal : Official Publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 10 Suppl 2: S141–6. doi:10.1007/s005860100287. PMID 11716011. 
  11. ^ Bansal S, Chauhan V, Sharma S, Maheshwari R, Juyal A, Raghuvanshi S (July 2009). "Evaluation of hydroxyapatite and beta-tricalcium phosphate mixed with bone marrow aspirate as a bone graft substitute for posterolateral spinal fusion". Indian Journal of Orthopaedics 43 (3): 234–9. doi:10.4103/0019-5413.49387. PMC 2762171. PMID 19838344. 
  12. ^ Kundu, B; Lemos A; Soundrapandian C; Sen PS; Datta S; Ferreira JMF; Basu D (2010). "Development of porous HAp and β-TCP scaffolds by starch consolidation with foaming method and drug-chitosan bilayered scaffold based drug delivery system". J Mater. Sci. Mater. Med. 21 (11): 2955–69. doi:10.1007/s10856-010-4127-0. PMID 20644982. 
  13. ^ He, GL, Assessment of Fluoride Removal From Drinking Water by Calcium Phosphate Systems