Belfast-based Phion Therapeutics has won the main prize at this year's InterTradeIreland Seedcorn competition.
Phion has developed a new drug delivery system which it licenses to pharmaceutical companies.
As part of the award the company also won a cash prize of €100,000.
The other main winner was Cerebreon Technologies, which was named Best New Start Company. The Donegal-based company won a cash prize of €50,000.
It is developing fintech software targeted at the UK insolvency industry.
Now in its 15th year, Seedcorn is the island of Ireland's biggest business competition for new start and early stage companies in any sector - north and south.
With over 275 competition entries, the winners went up against companies in a range of sectors including medical devices, technology, fintech, design engineering, diagnostics and digital ticket sales.
Since it started in 2003, the 2775 companies that have gone through the competition have raised over €229m.
