Appeal 2007-0313
Application 10/414,447
failure” (id., ¶ 3). The Specification describes “crystalline Form-I and
Form-II of Valsartan” (id., ¶ 8).
The disclosed process for preparing Form I crystalline valsartan
comprises “a) dissolving Valsartan in a C4-C6 straight or branched chain
ketone solvent at 60 - 65°C; b) adding an aliphatic hydrocarbon solvent
accompanied by cooling; c) isolating and drying the product of step (b) to
obtain crystalline Form-I of Valsartan” (id. at ¶¶ 18-21). In a working
example, Form I crystalline valsartan is made by dissolving valsartan in
methyl isobutyl ketone and precipitating with hexane (id. at ¶ 56).
The disclosed process for preparing Form II crystalline Valsartan
comprises “(i) dissolving Valsartan in a C4-C6 ketone solvent at 50-55°C
temperature; ii) adding an aliphatic hydrocarbon solvent accompanied by
cooling; iii) isolating and drying the product of step (ii) to obtain crystalline
Form-II of Valsartan” (id. at ¶¶ 32-35). In a working example, Form II
crystalline Valsartan is made by dissolving valsartan in methyl propyl
ketone and precipitating with hexane (id. at ¶ 57).
The Specification provides X-ray diffraction patterns for Form I and
Form II crystalline valsartan (Figures 1 and 3, respectively), as well as the
X-ray diffraction pattern for “crude Valsartan, which was recrystallised in
dichloromethane followed by ethyl acetate . . . , which is having an
amorphous pattern by its X-ray diffractogram” (id. at ¶ 55 and Figure 5).
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