Chemistry Reference
In-Depth Information
achieved with an amorphous solid dispersion or the challenges of stability that are
overcome that lead to patentability of the particular inventive amorphous solid disper-
sion. These aspects of the invention that should be discussed in the speci
cation show the
patentability of the amorphous solid dispersion over the prior art. The key is that these
advantages should be tied to the dispersion itself. Patenting the amorphous solid
dispersion as a composition of matter means that the properties showing the superiority
or unexpected advantages are properties of the composition as a whole.
Claims 3 and 4 at the beginning of the chapter capture these ideas. In claim 3, the
solid dispersion has a single glass transition temperature (
T
g
). This is an indication of
the miscibility of the amorphous drug in the polymer matrix. This property indicates the
homogeneity and single-phase character of the solid dispersion [4]. The stability of an
amorphous sold dispersion, as mentioned, is an important property of the dispersion and
can be used as evidence of patentability but also to claim the dispersion. According to
claim 4, the amorphous sold dispersion is stable for at least 72 h at 60
C and 75% relative
°
humidity. This serves to de
ne what solid dispersions of the amorphous drug in the
polymer matrix are within claim 4, those with the recited stability. But, this also serves to
distinguish the claimed solid dispersions from prior art dispersions that are not stable by
comparison. While such properties are described in the speci
cation, that data supporting
them are typically the subject of working examples.
This leads to the second function of the speci
cation
—
enabling one of ordinary skill
in the art to make and use or
“
practice
”
the invention. The speci
cation must also
“
the invention, that is, teach a person skilled in the art how to make and use the
invention. This is a second purpose of the written description. The speci
enable
”
cation is not
written to the public at large but to those skilled in the relevant art. The question of
enablement looks at whether a particular claim is
“
supported
”
by the speci
cation, that is,
whether the speci
cation contains suf
cient disclosure for one of ordinary skill to
practice the claimed invention
The test of enablement
is not whether any experimentation is needed, but whether, if experimentation is
necessary, it is undue.
20,23
Many factors may be considered when looking at enablement
or asking whether
“
without undue experimentation.
”
is necessary. As set out in
In re Wands
,
factors to be considered include, but are not limited to, (a) the breadth of the claims,
(b) the nature of the invention, (c) the state of the prior art, (d) the level of one of ordinary
skill, (e) the level of predictability in the art, (f) the amount of direction provided by the
inventor, (g) the existence of working examples, and (h) the quantity of experimentation
needed to make or use the invention based on the content of the disclosure.
23
The speci
“
undue experimentation
”
cation can meet its enablement function in the expositive discussion of
the invention. That discussion often walks through the various aspects of the invention
explaining them
rst as broad concepts and then re
ning them in terms of speci
c
embodiments. The expositive discussion in the speci
cation would describe the class of
polymers by their common features, for example, monomer content, molecular weight,
and their ability to disperse and stabilize the amorphous API. This type of disclosure
23
In re Wands
, 858 F.2d 731, 737 (Fed. Cir. 1988) (reversing the PTO's determination that claims directed to
methods for detection of hepatitis B surface antigens did not satisfy the enablement requirement);
see also
MPEP § 2164.01.
