SAN FRANCISCO — Lining up with California courts, the U.S. Court of Appeals for the Federal Circuit ruled Monday that the Food, Drug & Cosmetic Act does not preempt private actors from using California law to crack down on unapproved drugs.

The ruling is a partial win for Allergan and its attorneys at Gibson, Dunn & Crutcher, who will now use it to prevent Athena Cosmetics from marketing in California a prostaglandin-based eyelash enhancer that has not been approved by the FDA.