AstraZeneca PLC (AZN) won an injunction from a New Jersey federal court to continue barring Apotex Inc. from making a generic version of the pharmaceutical company's children's asthma medication Pulmicort Respules.

The latest action will make it more difficult for Apotex, which has approval for a generic version of the drug by the U.S. Food and Drug administration, to lift the ban.

Last month, U.K.-based AstraZeneca won a temporary ban to protect the drug from generic competition, after filing a lawsuit seeking a patent-infringement ruling against Apotex after the Canadian drug maker won approval for its generic version.

AstraZeneca's patents covering Pulmicort Respules expire in 2018 and 2019. The company said Wednesday it had "full confidence in the strength of its intellectual property rights protecting Pulmicort Respules."

A trial date for the patent litigation hasn't been set.

Last November, AstraZeneca reached a settlement with Israel-based Teva Pharmaceutical Industries Ltd (TEVA), the first generic drug maker to gain FDA approval to sell cheaper copies of the asthma medicine.

Under terms of that deal, Teva agreed not to resume selling its version of the drug until Dec. 15, 2009, under an exclusive license from AstraZeneca for which Teva will pay a royalty on sales of the generic. That settlement ended litigation between the two companies in New Jersey federal court.

AstraZeneca's American depositary shares were up 0.3% to $41.23 in after-hours trading.

-By John Kell, Dow Jones Newswires; 201-938-5285; john.kell@dowjones.com