FDA awards rare double approval to generic seizure drug from Amneal

HAUPPAUGE, N.Y. In an unusual dual endorsement of a new medicine, the Food and Drug Administration has approved a generic drug for the control of seizures and rated it as bioequivalent to both the original branded formulation of the drug and the leading generic version of the product.

The new product, Extended Phenytoin Sodium Capsules, USP 100 mg, is made and marketed by fast-growing generic drug maker Amneal Pharmaceuticals.

The company called the approval “an exceptional case where an Amneal generic stands as an AB-rated, therapeutically equivalent alternative to both the brand and the leading generic product.”

Added Amneal spokesperson Cheryl Lechok. “This rare FDA double approval was granted based on completion of not one but two bioequivalence studies comparing the Amneal product to the brand, Dilantin [Parke-Davis], and Mylan’s generic extended phenytoin sodium product.”

Extended phenytoin sodium is indicated for the control of generalized tonic-clonic (grand mal) and complex partial (psychomotor, temporal lobe) seizures, and is also used to prevent and treat seizures occurring during or following neurosurgery. Since the product has a Narrow Therapeutic Index (NTI), Amneal pursued an unusual dual path for earning approval as a therapeutically equivalent alternative to both the brand and the leading generic.

Thus, the company filed an ANDA [abbreviated new drug application] on the product for approval as a generic alternative to Dilantin, while successfully completing a second bioequivalence study of comparison to the generic extended phenytoin sodium manufactured by Mylan.

Following normal procedure, the FDA first granted approval to Amneal’s Extended Phenytoin Sodium Capsules as being AB-rated to the brand last November. “Once that approval was granted, the FDA then reviewed the second bioequivalence study and Amneal’s additional request, ultimately providing the second approval. This rare double approval by the FDA provides the critical evidence of therapeutic equivalence needed by the physician, pharmacist and patient,” noted the company.