A putative class action in federal court in Newark alleges the maker of Excedrin Migraine is duping customers by charging a higher price for a medicine identical to a lower-priced line.

Novartis Corp., of East Hanover, N.J., sells Excedrin Migraine at a wholesale price of $3.60 for 24 tablets, which is 12.5 percent more than for its $3.20 priced Excedrin Extra Strength.

The plaintiffs in Yingst v. Novartis, filed Tuesday, allege that the drug maker has said the only differences in the products are their labels and packaging.

The plaintiffs say the unwarranted price difference constitutes fraud and false pretense under the N.J. Consumer Fraud Act, which allows for recovery of treble damages, legal fees and costs. They also claim unjust enrichment and seek disgorgement of profits.

A Novartis spokeswoman, Julie Masow, says the company does not comment on pending litigation.

The plaintiffs claim to represent a nationwide class of purchasers of Excedrin Migraine for a price greater than Excedrin Extra Strength after Aug. 1, 2005, when Novartis bought Excedrin from Bristol-Myers Squibb.

According to the suit, each tablet of Excedrin Extra Strength has, since 1978, consisted of 250 milligrams of acetaminophen, 250 milligrams of aspirin and 65 milligrams of caffeine.

Bristol-Myers introduced Excedrin Migraine in 1998, saying at the time that the product had the same formulation as Excedrin Extra Strength but with a different name and labeling to “provide important information about appropriate use and when to consult a doctor.”

A 1998 newspaper ad for Excedrin Migraine, cited in the suit, pictured the product alongside Excedrin Extra Strength and said, “Clinical research has just proven that the formula in Excedrin actually relieves migraine pain. And because of the distinct nature of migraines, the FDA worked with Excedrin to develop a different package with specific information for migraine sufferers. So now next to Excedrin, there’s [a] new package—same medicine—called Excedrin Migraine.”

The two products originally had the same price, but Novartis began charging extra for the migraine label after the 2005 takeover, the plaintiffs allege.

Class representative Kerri Yingst of Cherry Hill says she bought Excedrin Migraine in spite of its higher price because she thought it was superior to Excedrin Extra Strength.

Plaintiff lawyer Todd Muhlstock of Baker Sanders in Garden City, N.Y., who filed the suit with Eric Gibbs of Girard Gibbs in San Francisco, says he knows of no case law in New Jersey addressing comparable products sold at different prices. But, he adds, “the case law in New Jersey is way more generous than this fact pattern.”■