The World Anti-Doping Agency has approved the list of banned substances that will be in place for the London Olympics, with one previously prohibited asthma drug to be permitted in certain forms.

WADA's executive committee met in Lausanne, Switzerland, on Saturday to approve the list that will apply to all accredited sports in 2012, but will not publish it until Oct. 1.

However, it said one of the biggest changes was that the asthma drug formoterol will be allowed when inhaled "at therapeutic doses."

WADA also said it plans to put more emphasis on collecting blood samples at doping tests. It said only 4 per cent of all doping samples collected this year were for blood, and that it will aim for that figure to rise to 10 per cent next year.