The US FDA has granted Acrux (ASX: ACR) approval to commence Phase III clinical trials of its Testostorone MD-Lotion.

The open-label trial will involve up to 150 hypogonadal men, who will take the recommended dosage for a period of four months.

Thanks to the approval, Acrux remains on target to launch the product in the fourth quarter of 2009, the company said.

Acrux said the product had several distinct advantages over current leading testosterone treatments.

It is a quick-drying solution that is applied to the armpits via a no-touch applicator, compared to the current treatments of a slow-drying gel which must be rubbed into the shoulders, upper torso or arms.

Low testosterone sufferers undergoing current treatments run the risk of transferring the drug to others due to treatment residue remaining on the hands.