Shire has signed a deal with Sandoz under which it will supply an authorised generic of its ADHD drug Adderall XR (mixed amphetamine salts).

The group said this week that Sandoz, the generics arm of Swiss drug giant Novartis, has agreed to exclusively sell its formulation of the drug from July 2016.

Shire will manufacture and supply all dosage strengths of the authorised generic for distribution by Sandoz in the US, and stands to receive an undisclosed royalty on sales of the product.  

Generic competition has taken a huge bite out of sales of Adderall XR, but the drug remains an important one for Shire, still generating more than $80 million a quarter.