Dicalcium phosphate anhydrous

The hydrolysis of Cap2 in solutions containing phosphates and carbonate ions results in the formation of fluor-, fluor-hydroxy- or fluor-carbonate-apatites. Fluor and fluor-hydroxy- apatites can also be formed by the hydrolysis of dicalcium phosphate (anhydrous or dihydrate), DCPAor DCPD, respectively, in solutions containing fluoride ions [121] or from the hydrolysis of any other calcium phosphate salt. 

Dicalcium Phosphate (Anhydrous or Dihydrate) Calcium Phosphate... 

MCC, microcrystalline cellulose DCP, dicalcium phosphate, anhydrous ND, not detected. Accelerated stability condition was 70°C/75% RH for 1 week. 

Fig. 8 Microcrystalline cellulose (Vitacel) (A), dicalcium phosphate dihydrate (Bekapress D2) (B), and dicalcium phosphate anhydrous (Dicaphos AN) (C).

From a thermodynamical point of view, only two calcium phosphate phases are stable at ambient temperature and pressure in SBF, monetite (DCPA, dicalcium phosphate anhydrate, CaHP04) (Nancollas, 1977 Jinawath et al., 2001)... 

Dicalcium phosphate (anhydric) DCPA Ca(HP04) 1.00 1.26x10 ... 

Figure 1. Solubility isotherms of calcium phosphate phases in the system Ca(0H)2-H3P04-H20 at 37°C. DCPD is dicalcium phosphate dihydrate, brashite DCPA is dicalcium phosphate anhydrous, monetite OCP is octacalcium phosphate p-TCP is p-tricalcium phosphate and OHAp is hydroxylapatite. pignre 1.1 from Elliott (1994), reprinted with permission from Elsevier Science.]...

Dicalcium phosphate dihydrate [CaHP04.2H20] Dicalcium phosphate anhydrate [CaHPOJ Octacalcium phosphate [CagH2 (P04)6.5H20] Tricalcium phosphate [Ca3 (P04)2] Hydroxyapatite [Ca o (P04)6 (OH)2] Tetracalcium phosphate [Ca4 (P04)20]... 

Dicalcium phosphate (anhydrous or sometimes as the dihydrate) has many uses. These include glass manufacture, plastics stabilisation, fertilisers and animal feeds. In addition, it is used as a dough additive, a nutrient and a dietary supplement. In pharmacy, it is used as a tablet diluent and dispersant calcium phosphates have other medical applications [32]. Other uses include paint and pigments and in toothpaste as a secondary abrasive. 

Tetracalcium phosphate (Ca4(P04)20) Dicalcium phosphate anhydrate (CaHP04) Sodium phosphate aqueous solution Chow, 1998... 

Ca-P has a Ca P ratio of 1.67 (hydroxyapatite). With a decrease of the Ca to P ratio, other Ca-defident phases occur like tricalcium phosphate (TCP, Ca P ratio 1.50), octacalcium phosphate (OCP, Ca P ratio 1.33), dicalcium phosphate anhydrous (DCPA or Monetite, Ca P ratio 1.00), and dicalcium phosphate dihydrate (DCPD or Brushite, Ca P ratio 1.00). Most of these caldum deficient compounds are used as raw material for sintering procedures for ceramics, or as ingredients for example, Ca-P cements. TCP and HA will be discussed more in detail, since these materials are most used for biomedical applications. 

Syntmyms (a) MCP Monocalcium Phosphate, Monohydrate Acid Calcium Phosphate, Calcium Superphosphate Calcium Biphosphate Primary Calcium Phosphate (b) DCP Dicalcium Phosphate (Anhydrous or Dihydrate) Dibasic Calcium Phosphate Calcium Monohydragen Phosphate Secondary Calcium Phosphate (c) TCP Calcium Phosphate Tribasic (d) Calcium Pyrophosphate Chemical Formula (a) CaH4(P04)2Hj0 (b) CaHP04 or... 

Schmidt and coworkers have carried out determinations of the surface acidity of pharmaceutical excipients and used a variety of absorption indicators to span the ranges of observed the acid strengths. In one study, the surface acidity of microcrystalline cellulose and dicalcium phosphate anhydrate was evaluated using thymol blue, bromcresol green, bromcresol purple, and phenol red as the absorption indicators. " Using the pH dependence of dye absorbance published in the paper, it was concluded that Hq was approximately 1.0 for dicalcium phosphate anhydrate, and approximately 4.0 for microcrystalline cellulose. 

FIGURE 2 Diffuse reflectance spectra, transformed to an absorbance scale, of bromcresol green adsorbed onto dicalcium phosphate anhydrate (solid trace), sorbitol (broken trace), and sodium bicarbonate (dashed trace) (H. G. Brittain, unpublished results). 

CaHP04 DCPA Dicalcium phosphate anhydrous (monetite) stability 2 < pH < 4... 

Chae, T., Yang, H., Ko, F., Troczynski, T., 2014. Bio-inspired dicalcium phosphate anhydrate/ poly (lactic acid) nanocomposite fibrous scaffolds for hard tissue regeneration In situ synthesis and electrospinning. Journal of Biomedical Materials Research, Part A 102, 514-522. 

Hirayama, S., Takagi, S., Marcovic, M., and Chow, C. L. 2008. Properties of calcium phosphate cements with different tetracalcium phosphate and dicalcium phosphate anhydrous molar ratios. Journal of Research of the National Institute of Standards and Technology 113 311-20. 

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