The lawsuit implies that inhalers are a special case, where the normal FDA rules don’t apply. By adding new patents covering inhalers the manufacturer triggers FDA rules preventing the FDA from approving a generic, or so the lawsuit implies:

Because of the complexities of producing drug-device combinations like inhalers, the Food and Drug Administration employs a special set of regulatory requirements when approving generic inhalers.

Specifically, when a brand-name manufacturer lists a patent for a product with the Food and Drug Administration (FDA), the FDA is prohibited from approving the generic version of that product until the patent protection expires or is challenged and overturned.