Appeal No. 2001-1241 Page 7
Application No. 09/101,234
. . .
[C]ompression diluents, including waxes are also known. . . . These
waxes are usually if not always chemically inert, can impart
sustained release characteristics when required and, as drug
diluents, provide a level of cohesion which approaches the ideal. . . .
The disadvantage with waxes inheres in their flow properties,
however. . . . [M]ost waxes tend to clump, not flow, and as such
are generally inappropriate for use in tabletting presses and similar
production machinery. . . . A free-flowing granulated wax is
therefore the theoretical ideal as a diluent for incorporation into a
compressed drug containing matrix.
. . .
SUMMARY OF THE INVENTION
It has been identified that wax-containing granules having improved
flow properties are obtained when one or more pharmaceutically-
acceptable waxes are admixed in the melt with one or more flow
improving additives [e.g., acrylic polymers], with cooling and
granulation of the admixture.
Column 1, line 10 to column 2, line 23.
The examiner has not adequately explained why a person of ordinary skill
in the art would have been motivated to substitute Schade’s cross-linked polymer
for the non-crosslinked polymers used by Shukla. The examiner takes the
position that substituting one polymer for the other would have been obvious
because “both the references teach modifying the viscosity or rheology of the
composition, using the instant polymers.” Examiner’s Answer, page 4. What
Schade actually says, however, is that the disclosed cross-linked polymers are
useful as “stabilizers in oil-in-water emulsions.” We understand the reference to
“stabilizers” to mean that the polymers prevent the emulsion from separating into
hydrophobic and hydrophilic phases, not that they change its viscosity or
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