The $18.5m (€14.6m) facility, located at Kapuni, near Taranaki on New Zealand's north island, will also become GSK's preferred supplier of tablet-grade pharmaceutical lactose.
GSK vice president of new products and global procurement, Steve Bucksley, said the spur to seek new suppliers of lactose came from concerns about transmissible disease problems affecting cattle in the northern hemisphere.
"Security of supply is a big issue for us and the pharmaceutical industry in general, and sourcing a proportion of our requirements from New Zealand means we are spreading our geographic risk," he said.
Pharmaceutical lactose is used by GSK in respiratory products which deliver inhaled medicines to treat a range of diseases and medical conditions, and make up its largest therapeutic category, with turnover of £4.4bn (€6.4bn) out of the GSK's total pharmaceutical revenues of £17bn in 2004.
Inhalation-grade lactose currently makes up only a small part of the $100m pharmaceutical lactose market, but Sandra Neild from Lactose New Zealand says inhaled drug delivery is on the increase.
"Several leading pharmaceutical companies are conducting extensive research using inhalation drug delivery as an alternative to tablets or injection. It provides for accurate and controlled release, access to new active chemicals not available when ingested in tablet form, and the alternative to injection holds a strong consumer interest," she said.
Speaking at the opening of the Kapuni plant, the Chief Executive of NZ dairy co-operative Fonterra, Andrew Ferrier, said the new plant was a result of the company's strategy to develop high-value, niche-market opportunities.
Lactose New Zealand is the world's second largest supplier ofpharmaceutical lactose, and the firm will be seeking partnerships with other leading pharmaceutical companies for the supply of its Wynhale brand of inhalation grade lactose.