A federal judge has certified a class of direct purchasers of the drug Provigil in their antitrust case against generic drug makers Ranbaxy Laboratories and Mylan Pharmaceuticals.

U.S. District Judge Mitchell S. Goldberg of the Eastern District of Pennsylvania granted class status to direct purchaser plaintiffs who claimed the drug companies delayed the introduction of a generic version of the wakefulness drug Provigil into the market.

A $512 million settlement in the case was reached in April between the plaintiffs and former defendants Cephalon Inc. and generic drug makers Teva Pharmaceutical Industries Ltd., Teva Pharmaceuticals USA Inc. and Barr Pharmaceuticals Inc. Mylan and Ranbaxy were not part of that settlement, however.