A federal judge has certified a class of third-party purchasers who allege that GlaxoSmithKline filed “sham” citizen petitions with the Food and Drug Administration that kept generic versions of its nasal spray called Flonase off the market for two years.

U.S. District Judge Anita Brody of the Eastern District of Pennsylvania narrowed the class to only those who purchased the generic equivalent after it became available and to those who purchased Flonase in one of four states.