DCP is an insoluble inorganic diluent. The anhydrous and dihydrate forms of dicalcium phosphate are used in pharmaceutical development (Rowe et al., 2009). The dihydrate form of dicalcium phosphate presents good flow properties and low hygroscopicity.
Based on the temperature and humidity, however, the dihydrate form tends to lose water of hydration, which can cause chemical instability of APIs in dosage forms. Because of the absence of water in its crystal structure, the anhydrous form of dicalcium phosphate exhibits higher porosity, leading to better compressibility and faster disintegration. If you want to buy DCP then search for dicalcium phosphate for sale online or you can also find it in your local chemical stores.
The dihydrate form transforms into the anhydrous form because of the high temperature in the wet granulation process. Comparison between the two forms of DCP showed that the anhydrous form has better intraarticular porosity and better compressibility than the dihydrate form.
In addition, because of the higher intraarticular porosity, the disintegration of anhydrous DCP is better than the dihydrate form. Both forms of dicalcium phosphate, however, needed a swelling-type disintegrant in the formulation when used. Different grades of dicalcium phosphate are available, with coarse grade used for direct compression and milled grade for wet granulation or roller compaction. The milled grade has an alkaline pH and cannot be used with API incompatible with basic pH.