Inventor who started on £16,250 sues former employer for £366m over antimicrobial plaster patents

Dr David Parsons, an analytical chemist who spent more than 30 years at FTSE 100 medical firm Convatec, is claiming up to £366m at the High Court, arguing his inventions created an "outstanding" benefit for his employer. Parsons, of Hoylake, Merseyside, joined the company in 1991 on a salary of just £16,250 and rose to become a director. His work on silver-based antimicrobial wound dressings, covered by seven patent families, is said to have generated billions of dollars for Convatec.

After leaving Convatec in 2023, Parsons is seeking a portion of the profits generated by his patented Aquacel dressings.

Convatec contests the claim; the case came before the Court of Appeal this week in a dispute over the scope of the trial.

A full six-week High Court trial is not expected to begin until 2028.