Calcium Phosphate Excipients - Innophos

Figure 21 Figure 22
20
20
Tablet Hardness (kp)
16
12
8
4
0
8
0.5% Mg Stearate
1.0% Mg Stearate
(2.0% Mg Stearate gave no tablets)
10 12 14 16 18 20 22
Compaction Force (kN)
Tablet Hardness (kp)
16
12
8
4
0
8
2-Minute blend
30-minute blend
10 12 14 16 18 20
Compaction Force (kN)
22
COMPRESSIBILITY PROFILE OF TRI-TAB ®
Lubricant Level Effect
Tooling
Because they are inorganic materials, the calcium
phosphates are, in general, more abrasive than
the softer organic materials. Interestingly, calcium
phosphates are also used as polishing agents in
toothpaste, because they clean and polish yet do
not abrade a tooth surface. When tableting a
formulation containing calcium phosphates, each
press production group will optimize the choice of
tooling to achieve maximum tool life. Depending
on the formulation, the press, production conditions
and the size and shape of tooling, a given set of
tools of a specified steel will be selected. Often
premium steel or tungsten carbide tooling is
recommended. Calcium phosphates have long
been used in direct compression formulations on
standard presses and tooling by the multivitamin/
mineral manufacturers. Interestingly, A-TAB ® ,
Table 13
COMPRESSIBILITY PROFILE OF TRI-TAB ®
Lubricant Blend Time Effect with 0.5% Magnesium Stearate
the granular dicalcium phosphate anhydrous,
has been specially manufactured to be less
abrasive than the powdered dicalcium phosphate
anhydrous. This may prove beneficial in reducing
the potential for tool wear.
Loading Capacity
The loading capacities of DI-TAB ® , TRI-TAB ® and
A-TAB ® are shown in Table 13. Here, blends of
excipients were formulated with a poorly
compressible, fine granular Vitamin C. Blends
were tableted on a laboratory hydraulic press
(Carver press). The hardness of A-TAB ® tablets
was very similar to, or slightly better than, that
of DI-TAB ® and TRI-TAB ® tablets, indicating the
ability of all three excipients to act as compressible
carriers. The addition of microcrystalline cellulose
will increase the loading capacity of a formulation.
Loading Capacity With Fine Granular Vitamin C
% Fine Granular Vitamin C Tablet Hardness (kp)
In Formulation A-TAB ® DI-TAB ® TRI-TAB ®
0 20 14 20
10 15 11 13
25 10 10 8
50 5 5 3
Carver press, 1/2-in. die, 3 seconds dwell at 2 metric tons force, 1% Mg stearate for A-TAB ® and DI-TAB ® , 0.5% Mg stearate for TRI-TAB ® .
20