The Commission cleared the venture, which brings together two of the world's top dairy firms, after finding there would be no damage to market competition.
The 50-50 venture highlights how dairy firms may look to make extra money with added value ingredients, outside of their traditional sector.
Lactose naturally makes up between two and eight per cent of solids in milk.
Campina and Fonterra will combine their pharmaceutical lactose business, as well as their divisions for selling lactose for use in fine chemicals manufacture. They will also sell lactose as an excipient - a carrier or diluting agent in drug formulations.
The venture deal, signed in late March, is expected to target the Asia Pacific region for growth, making use of Fonterra's new factory for producing inhalation grade lactose in the region.
Sales offices will be opened around the world, however.
"Campina has a strong position in Europe and Japan, while Fonterra has been very successful in building a strong position in the Asia Pacific region, and has a major supply agreement with one of the world's leading pharmaceutical companies," said Andrew Ferrier, Fonterra's chief executive.