Sure, because inhalers aren't just drugs, they are drug-device combinations. If someone wants to make a generic, not only does the drug patent need to expire,

Sure, because inhalers aren't just drugs, they are drug-device combinations. If someone wants to make a generic, not only does the drug patent need to expire, but also the device patent. But nothing stops a company from developing their own device. The issue is that it won't be a generic - it will be a new inhaler. That's expensive to do.