hypertension [7]. This pharmaceutical
compound reported having 12 different
polymorphs and amorphous form [1].
Unfortunately, there is a lack of
information regarding the changes in the
properties of these polymorphs, especially
about transition during the manufacturing.
The habit or morphology of crystals
generally is obtained from solution satura-
tion, stirring rate, cooling rate, solvent
mixtu-re, additives, crystal seeds,
temperature, and impurities. Among the
various methods, the variation of the
dielectric constant of the solvent is effective
and practical in obtaining some phase [8].
Caused by finding different polymorphic
forms in pharmaceuticals solid among
commercial products will take much more
time, unrealistic, and inefficient. Therefore,
this study aims to learn polymorphic
changes under mechanical forces like
grinding and humidity variation
environments among phases of VAL.
Meanwhile, all VAL phases were produced
by recrystallizing the selected solvents. The
information resulting useful for pharmaceu-
tical development if there want to be
applied vary of polymorph forms.
Fig. 1. Structure formula of Valsartan [7].
2. MATERIALS AND METHODS
Materials
Valsartan (VAL) was obtained from
Zhejiang Huahai Pharmaceutical Co.,
LTD. (Batch No. C5271-13-196). All
other chemi-cals used were of
analytical grade. The solvents used n-
butyl acetate and acetonitrile was apply
without any purification.
3. Methods
2.1 Polymorphs preparation
The VAL bulk powder from the
market was amorphous form. To earn
different crystal forms of VAL was
obtained with recrys-tallization by two
organic solvents. An amount of VAL was
dissolved in some volumes of solvent (n-
butyl acetate or acetonitrile) at 15 – 20oC
for an hour. Then the solutions (or
suspensions) dried at room temperature.
After several hours the solid phase appears,
collected in a separate container, and
labeled.
2.2 Polarization Light Microscope
The morphology of crystalline habit
may observe firstly by Olympus BX53
model U-LH100-3 microscope with 400 x
magnification.
2.3 Fourier Transform Infrared
(FTIR) Spectroscopy
The sample fingerprints functional
groups were recorded by IR Prestige-21
Shimadzu, Japan. The samples were disper-
sed in KBr powder and compress by a
hydraulic press to form a compact
transparent disc. The spectrum of each
sample was recorded from 400–4000 cm–1.
2.4 Powder X-ray Diffraction
(PXRD)
Powder X-ray diffraction (PXRD)
was conducted by X-ray diffractometer
(X’Pert–Pro PANalytical, Netherland) with
Cu–Kα radiation (1.5 Å), at 40kV, 30 mA,
and fixed divergence slit 0.05o, receiving
slit 0.45 mm. All samples were scanned at
room temperature in the 2θ range of 5–50o
with 0.02 step size and 0.8 s per step, care
was taken to avoid phase transitions during
preparation.
2.5 Polymorphic Transformation
Evaluation