Under experimental conditions, bupropion
hydrochloride exhibited rapid photodegradation in aqueous media over a range of
pH values. Based on the seasonal
calculated values, bupropion hydrochloride, under certain conditions, may not
rapidly degrade by has the inherent capability to photodegrade.
7.b Air Compartment
In order to assess the effect upon the atmospheric
compartment, the vapor pressure of bupropion hydrochloride was estimated and
the UV spectra was measured. Data for
these tests are summarized in Section 15.a.
Vapor Pressure Estimate
The vapor pressure for bupropion hydrochloride is
estimated to be 2.0x10-7 torr.
It was experimentally determined as 3.74 (ą 1.17) x 10-7 torr
at 25°C. the vapor pressure is slightly
greater than 10-7 torr so bupropion hydrochloride could affect the
atmospheric compartment.
The determined vapor pressure value is very near the
limits of the gas saturation test method which is reflected in the relative
deviation of the measured values.
Because of the very low vapor pressure, the volatile hazard posed by
bupropion hydrochloride is considered slight or nonexistent under normal
conditions.
UV spectra
No significant absorbance was observed in the UV
spectrum above 300 nm. Spectra were obtained
in the range of 208 to 299 nm. The
ultraviolet spectrum of bupropion hydrochloride in 0.1N HCl solution exhibits a
maximum at 209.6 nm with an A (1%), 1cm) value of 3.127. the molar absorptivity at the maximum is
20.3 X 10-3.
Summary
Based upon the vapor pressure determination,
bupropion hydrochloride could affect the atmospheric compartment. Because if its high aqueous solubility and
relatively low vapor pressure, bupropion hydrochloride has a greater affinity
for the aqueous compartment.
Non-persistence in the atmospheric compartment is confirmed by a UV
absorbance greater than 290 nm and photodegradation in aqueous media. the atmospheric compartment properties are not
considered significant to warrant further evaluation of Tier 3, the atmospheric
compartment.
7.c Terrestrial Compartment
In order to assess the effect upon the terrestrial
compartment, the n-octanol/water partition coefficient was measured. Data for these tests are summarized in
Section 15.a.
GCPV/93/0011/03 12
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