Oh I can so sympathize with you hun. I have three different lots of meds to get in to DS17mths at the moment and it has been nothing short of a nightmare.
I tried giving it to him to do himself and he squirted it all over the floor, I tried putting it in his milk or juice or whatever and he refused to drink it as he could taste it. Restraining just sucked as both him and I became so upset.
In the end full on OTT praise is what is working. I sit on the floor with him and tell him what a good boy he is and he is so clever and well done and every single full of praise term I can think of over and over. He gets into the swing of it wanting to please me I guess so he takes it. It does take a while, like 15 mins but much nicer than the forcing him.
Good Luck