Chemist Warehouse’s billionaire founders have cleared the final hurdle in their long-held ambition to create a listed pharmacy and retail giant, saying they have big ideas for the group which will start trading on the ASX next month after shareholders backed their $30 billion merger deal.

The reverse takeover of Sigma Healthcare, a wholesaler and franchiser with brands such as Amcal and Discount Drug Stores, has taken more than a year to be approved by regulators and finally, on Wednesday, shareholders.