Which formula are you feeding? If it's anything like the F&T muesli,i would not know where to begin :( I cant find the ingredients to the 'maintenance' formula.
Protien pellets containing meat,meat derivatives,minerals and bran,extruded wholewheat biscuits with added vitamins, terrier meal, cooked flaked maize,cereal coating,dried meat greaves,cooked flaked peas,cooked flaked wheat,soya oil,extruded meat pellets.Most border collies are "nervous/hyperactive",add to this a food full of wheat,soya,derivatives of meat,terrier meal,extruded meat pellets,and i wouldnt hesitate to think you'de have a ticking time bomb on your hands

How much exercise does he get daily? I wouldnt bother with any 'medication' until you've sorted his food out.