Dublin-based pharmaceutical group Elan will invest $40 million (€45.6 million) in its Gainesville, Georgia, plant in the US over the next three to five years, creating around 100 jobs there.

The plant recently passed pre-approval by the US Food and Drug Administration (FDA) to manufacture two new pharmaceutical products. It manufactures Verelan and Verelan PM, Elan's formulations of the calcium channel blocker verapamil, which is used in the treatment of hypertension.

The first phase of the project includes a $10 million investment to expand the existing 52,000 sq ft building by an additional 13,400 sq ft. The second phase will expand the area to 150,000 sq ft.

The Gainesville plant currently employs 180 people - up 50 per cent on the previous year. By the end of the second phase, the facility will employ 280 people.

Elan was reprimanded by the FDA last year over conditions at the plant. The US regulator found that laboratory analytical equipment had not been maintained in good repair, nor had sufficient records of test results been kept.

But the FDA said the violations were not known to have caused any immediate risk to public health. At the time, Elan signed a "consent decree of permanent" injunction, committing it to meeting certain standards at the plant in the future and agreeing to annual inspections at its own cost for the following three years.

A spokesman for Elan said the investment in Gainesville was part of a continuing policy of development and expansion at all its plants. Last year, the company said it was investing more than €200 million in its Athlone facility. The spokesman said the company's investment plans had not been affected by the drop in its share price earlier this year after a Wall Street Journal report that was scathing of its accounting policies. "Elan is not any different as a business than it was last year," he said.