Because Solodyn contains an antibiotic drug that was first approved by the FDA prior to the enactment of the Food and Drug Administration Modernization Act of 1997, or FDAMA, Solodyn does not have the benefit of the protections offered under the Hatch-Waxman Act. That is why MRX didn't fill an infringement suit. MRX would not be entitled to an automatic 30-month stay of generic entry that would be available to a patent owner filing an infringement suit (If charges are filed within 45 days) based on receipt of a notice from the generic competitor. In short, the Solodyn patent does not expire until 2018 but is useless and they know it.