BASF Fine Chemicals Generic Drug Formulations 1998
ness of those obtained by Kollidon 25 can be achieved by using Kollidon 90
F at low pressures.
Conversely, there would be some point in changing over from Kollidon
90 F to Kollidon 25 or 30 if the vis- cosity of the solution used in granula-
tion is too high. In practice, however, the same hardness is usually achieved
by increasing the amount of Kollidon.
2.4 Tablet press
All the formulations were devised on rotary tabletting presses that were fit-
ted with 10 – 20 punches.
2.5 Effect of the physical proper- ties of the active substance
In the manufacture of tablets it is im- portant to define and appreciate the
90 80
70 60
40 4
6 8
10 12
14 16
50
Compression force kN H
a rd
n e
s s
N Kollidon 25
Kollidon 30 Kollidon 90 F
Fig. 2 Hardness of lactose tablets containing various Kollidon products wet granulation
140 120
100 80
40 60
crystalline grade Compression force: 25 kN
powder grade T
a b
le t
H a
rd n
e s
s N
Fig. 3 Direct compression of different types of ascorbic acid
40 ascorbic acid, 5 Kollidon VA 64
BASF Fine Chemicals Generic Drug Formulations 1998
physical properties of the active sub- stance. This particularly concerns the
particle size.
Fig. 3 shows the difference that can occur when ascorbic acid tablets of
the same composition are produced at the same pressure, but when the
active substance consists of crystals of two different sizes crystalline =
150 µm; powder = 150 µm.
2.6 Effect of the physical properties of the excipients
Characterization of the physical pro- perties of excipients is also important.
This is demonstrated in Table 2 in the light of the example of hydrochloro-
thiazide. Tablets of greater hardness are obtained if fine instead of coarse
Povidone K 90 is taken. To a certain extent, the disintegration and the
release are also affected.
2.7 M ethods of measuring the properties of tablets
The general instructions for the deter- mination of the corresponding pro-
perties of tablets are contained in the Pharmacopoeiae Ph.Eur. or USP. If it
is not stated to the contrary, the disintegration time is measured in
artificial gastric juice. The release is determined by the methods laid down
in the corresponding monographs for the tablets usually USP and in the
prescribed medium.
2.8 Information on dissolution of active substance
