32 Pharmaceutical Technology LABORATORY BEST PRACTICES 2018 P h a r mTe c h . c o m
ous settings; to include it in the graphical representa-
tion, the shear value measured was included at each
level setting.
Recrystallization of ibuprofen
In pharmaceutical manufacturing, recrystallization
parameters of active ingredients are known to not
only affect final product attributes such as chemical
purity, but physical properties as well. These will
include important characteristics such as solubil-
ity, particle size, specific surface area, f lowability,
wettability, and stability. The origin of these im-
portant physical properties can be traced to crystal
morphology and habit. United States Pharmacopeia
(USP) <941> (3) and USP <776> (4) address these
issues and the testing methods that can be used to
characterize the solid materials, as the final form
affects properties that commonly become critical
quality attributes of an API.
Ibuprofen has two well-known crystal habits. In the
original Boots (5) process, the final API was recrys-
Sample Preparation
Figure 2: Tachometer setup for vortex mixer setting
measurements.
Vortex Mixer
Tachometer
Table I: Vortex mixer measured shears.
Vortexer Type 1 (VORT-189)
PPD ID VORT-189
Level RPM Sheer (Pa)
1 1140 1.9E-02
2 1248 2.1E-02
3 1478 2.5E-02
4 2467 4.1E-02
5 2929 4.9E-02
6 3082 5.1E-02
7 3171 5.3E-02
8 3255 5.4E-02
9 3315 5.5E-02
10 3381 5.6E-02
Vortexer Type 1 (VORT-34)
PPD ID VORT-34
Level RPM Sheer (Pa)
1 925 1.5E-02
2 967 1.6E-02
3 1032 1.7E-02
4 1114 1.9E-02
5 1210 2.0E-02
6 1352 2.3E-02
7 1729 2.9E-02
8 2527 4.2E-02
9 2849 4.7E-02
10 3060 5.1E-02
Vortexer Type 2 (VORT-17)
PPD ID VORT-17
Level RPM Sheer (Pa)
On 2975 5.0E-02
Vortexer Type 2 (VORT-17)
PPD ID VORT-17
Level RPM Sheer (Pa)
1 2975 5.0E-02
2 2975 5.0E-02
3 2975 5.0E-02
4 2975 5.0E-02
5 2975 5.0E-02
6 2975 5.0E-02
7 2975 5.0E-02
8 2975 5.0E-02
9 2975 5.0E-02
10 2975 5.0E-02
Continued from page 29
