Three Bradford scientists are set to become multi-millionaires by selling their groundbreaking pharmaceutical firm for $200 million.

Professor Peter York, Dr Gwyn Humphreys, and Dr Mazen Hanna could make up to $40 million each in shares and cash when they sell Bradford Particle Design (BPD), the firm they founded in 1994, to American pharmaceutical giant Inhale.

The sale - for the equivalent of £136 million at today's exchange rate - has been approved by the three company founders and should go ahead in January. And the buy-out will also mean a huge payday for Bradford University which is a major shareholder in the firm.

A BPD spokesman said: "It's great news for Bradford. It's really good to see the fundamental technology that they have developed in Bradford being recognised in this way.

"It means we will be able to fulfil the true potential of our technology. This will truly put Bradford technology on the world stage."

The spokesman added that the three scientists would receive 90 per cent of their payout in Inhale shares and the remaining ten per cent in cash.

The three are expected to continue working from the company's Listerhills offices and to remain in control of their work, reporting only to Inhale's senior management.

BPD was founded in 1995 as a spin-off from Bradford University's pharmacy department. Its world-leading work began as speculative experiments investigating how powder particles are made for medicines. But now the firm has blossomed into a major pharmaceutical firm with 40 staff and a turnover of £1.5 million a year.

The firm, which counts multi-national giants Glaxo-Welcome and Astra Zenica among its clients, hit the headlines earlier this year when Trade and Industry Secretary Stephen Byers opened its new £1million manufacturing facility at Listerhills Science Park in Bradford.

Ajit Gill, Inhale's president and chief executive officer, said he believed BPD's world-beating technology would now become a major player on the world's pharmaceutical stage.

Bradford University registrar and secretary Nick Andrew said: "The university will receive a significant sum but most of it will be in the form of shares that are subject to a lock-up deal. We then have to take the cost of our investment over the last seven years and taxation issues into account before being able to say how much money we have made."