Consisting of . . . and optionally . . .

I am writing a separate post on Galderma Labs., L.P. v. Amneal Pharms. LLC (Fed. Cir. March 25, 2020), but wanted to note the claim language found in Gladerma’s U.S. patent No. 8,206,740.  In particular, I was first surprised to see the final element of the claim written as an “optional” limitation:

1. An oral pharmaceutical composition of doxycycline, which at a once-daily dosage will give steady state blood levels of doxycycline of a minimum of 0.1 μg/ml and a maximum of 1.0 μg/ml, the composition consisting of

(i) an immediate release (IR) portion comprising 30 mg doxycycline;

(ii) a delayed release (DR) portion comprising 10 mg doxycycline; and

optionally, (iii) one or more pharmaceutically acceptable excipients.

The MPEP offers some ambiguous thoughts on use of the term “optionally” within claim language — concluding that it may raise indefiniteness concerns where ambiguity arises from a “list of potential alternatives.” MPEP 2173.05(h) Alternative Limitations.   In the usual claim situation, an “optional” limitation creates confusion because it doesn’t appear to do any actual work in the claim because a claim “comprising” a list of features may also include other features as well. In that situation, the ambiguity comes into play because we still want to assign some meaning to the claim element even though it is largely meaningless.

In the claim above, however, the “optionally” language complements a “consisting of” transition.  It does substantial work because of the closed transition — without the optionally limitation a formulation having the “pharmaceutically acceptable excipients” would be found not literally infringing.