Johnson & Johnson has reached another deal to settle a patent dispute concerning its attention-deficit hyperactivity disorder drug Concerta.

Impax Laboratories and partner Teva Pharmaceutical Industries have settled their lawsuit against J&J's Alza Corp unit after the latter granted the firms a licence to sell their copies of Concerta (methylphenidate) by July 14 next year. The generic of the ADHD drug is included in a strategic alliance Impax has with Teva and the Israeli company is waiting for its versions to be approved by the US Food and Drug Administration.

Concerta has been a big earner for J&J and Impax, quoting data from Wolters Kluwer Health, said that US brand and generic sales of the drug were approximately $1.20 billion for the 12 months ended July 2012.

However, this highlights a potential problem for Impax and Teva to get market share next summer. An authorised generic was launched last year by Watson Pharmaceuticals after a deal was signed with J&J in 2010, which sees the healthcare giant supply generic Concerta and take a cut of the profits.

Concerta is indicated for ADHD in children six years of age and older, as well as for adults up to the age of 65.