Chemistry Reference
In-Depth Information
As with solid-state chemistry, a patent application has both form and substance
through which it satis
es the legal requirements for patentability. There are essentially
two fundamental parts to a patent: the speci
cation and claims. Each has a different
function. The speci
cation describes the invention and includes a written description,
drawings, and examples. The patent claims are particularly important because they
delineate the patented invention and thereby de
ne the intellectual property right.
Whether or not something infringes the patent depends on whether or not it comes
within the scope of the patent claims. This chapter considers some key aspects of
patenting amorphous solid dispersions of pharmaceuticals by surveying the information
to be included in a patent (or patent application) to support and present robust patent
claims to amorphous solid dispersions. The chapter describes the patent examination
process and three common types of patent applications.
13.2 AN AMORPHOUS SOLID DISPERSION AS A PATENTABLE
INVENTION
Consider the following patent claim set for an amorphous solid dispersion of a pharma-
ceutical compound:
1
The claimed invention is
2
1. A solid dispersion of amorphous “drug” in a “polymer matrix.”
2. A solid dispersion of claim 1, wherein the weight ratio of drug to polymer matrix
ranges from about 20:80 to about 5:95.
3. A solid dispersion of claim 1, having a single glass transition temperature (
T
g
).
4. A solid dispersion of claim 1, being stable for at least 72 h at 60
°
C and 75% relative
humidity.
5. A pharmaceutical composition comprising a solid dispersion of claim 1 and at least
one pharmaceutically acceptable excipient, wherein the drug is present in a thera-
peutically effective amount.
6. A method for treating a condition in a human patient comprising the step of
administering to the human patient a therapeutically effective amount of drug in
the form of a solid dispersion according to claim 1 or in the form of a pharmaceutical
composition of claim 5.
These claims represent those found in patents directed to an amorphous solid dis-
persion of a pharmaceutical. Independent claim 1 recites the amorphous solid dispersion
1
This claim set is illustrative and for discussion purposes only. It does not pertain to, nor is it developed from,
any particular patent or patent application.
2
Note that we are treating the words “drug” and “polymer matrix” as if they are not general terms but, as they
would in a patent, they define a specific drug and a specific polymer matrix that would be done in a patent. Note
also that while a “polymer matrix” is mentioned here, the matrix material dispersing the amorphous drug may
not be a polymer or a mixture of polymers. It may be any number of materials that can disperse an amorphous
drug. The terms used here are used for ease of discussion and their easy recognition in the art.
