Navin and Varsha Engineer
Rank 2017

Chemidex, the Surrey pharmaceuticals operation owned by Engineer, 66 later this month, and his wife Varsha, 62, is making healthy profits. The couple’s largest four companies made more than £20m combined last year, with the two biggest businesses holding £113.4m net assets. A former Boots pharmacist, Kenyan-born Engineer established a chemist chain that he sold in 1999 for about £12m, but rather than retire he put his money into building up a pharmaceuticals giant. Debt-free and with a string of patents, Chemidex is worth £1.1bn with pharma company ratings so high, to which we add £100m for other wealth.