Calcium Phosphate Excipients - Innophos

PHYSICAL AND CHEMICAL PROPERTIES
Formulas
The chemical formulas and molecular weights
of dicalcium phosphate dihydrate, dicalcium
phosphate anhydrous and tricalcium phosphate are
listed in Table 1. As shown, dicalcium phosphate
(or dibasic calcium phosphate) is produced as
either the dihydrate or the anhydrous salt.
Commercial tricalcium phosphate is primarily
hydroxyapatite, with a general formula of
Ca 5
(OH)(P0 4
) 3
. It can also be referred to as
tribasic calcium phosphate since during preparation
from phosphoric acid, all of the three hydrogens are
replaced by calcium. In nature, hydroxyapatite is the
primary inorganic structural material in bones and
teeth. It is different from the mineral whitlockite,
with a formula of Ca 3
(P0 4
) 2
.
TCP-DC is Innophos’ patented (US Patent
7,226,620) directly compressible ingredient
designed to make high calcium load tablets
easier to make. It is a granulated product made
from tricalcium phosphate, NF/FCC and povidone
USP, with an elemental calcium content of
approximately 35%.
Table 1
DCPD DCPA TCP
Name ◆ Dicalcium Phosphate ◆ Dicalcium Phosphate, ◆ Tricalcium Phosphate
Dihydrate Anhydrous ◆ Tribasic Calcium Phosphate
◆ Dibasic Calcium ◆ Dibasic Calcium ◆ Tricalcium Orthophosphate
Phosphate Dihydrate Phosphate, Anhydrous ◆ Hydroxyapatite
CAS 7789-77-7 7757-93-9 12167-74-7
Number
Formula CaHPO 4
•2H 2
O CaHPO 4
Ca 5
(OH) (PO 4
) 3
or
Ca 10
(OH) 2
(PO 4
) 6
or
10CaO•3P 2
O 5
•H 2
O
Molecular 172.09 136.06 1004.7
Weight
5