They can patent minocycline and it's derivatives. If they made a brand name minocycline, no one would ever use it because it's already generic. However if they

They can patent minocycline and it's derivatives. If they made a brand name minocycline, no one would ever use it because it's already generic. However if they can make a derivative that is more efficacious (even if it's only slightly different), they can brand that and sell it under patent for a while.