We've been giving oral meds to our male veiled for about a week now, but have the luxury of two sets of hands. I gently hold Neil in my hands (I cup them and let him rest in the middle) being mindful of not putting my fingers over the top of his back, but with them close enough that he can move a little, but not reach for the syringe.
Then my son gently strokes his bottom lip. Neil will eventually open and we can squirt in a little bit at a time. It takes a while some days, and on others (if he's feisty) he's opened right up. He bites at the syringe or my son's finger, which means he's ticked off at the whole process, but we get the meds in.
He seems to tolerate that method best for us, but he is also only about 9 months old and generally pretty people-friendly for a cham.
The size of the syringe can matter, too. We use a very small one that holds about a ml. One that came with a second prescription was larger and did not work well at all.
As others have said, be mindful of the lips and gums. Our little guy has early mbd, too, so we're on a similar path. Good luck!
Yesterday she ate one superworm w/ the Calcium on it. Now she won't eat anything or drink. 
