You could try a two-person deal: a holder, and a medicine giver. The medicine giver can work with the syringe and the mouth, while the holder keeps the rat safe, but steady.
That pink medicine is made especially to taste irresistable to rats, very sweet, but Gus doesn't like it, either. Gregor, on the other hand, thought it was the best "sweetie" in the world. Maybe Sachi will decide to like it.
How old is she?
One last suggestion, which might be the easiest: mix the medicine with a food that Sachi just can't resist. For Gus, we mixed it with some rice pudding...trust me, he ate that!
If Sachi has NO favorite foods, which is not likely, you can always get a tube of the ferret vitamin, "Ferretvite." Not only is it good for rats as well as ferrets, but it's made to taste great! (In fact, this is Gus' favorite sweetie!) Mix the med with the Ferretvite, but remember not to overdo the vitamins; don't do much more than 1/2 a teaspoon TOTAL per day, per pound of rat.
