Tylan50 comes in a water soluble, oral powdered form, and in an injectable liquid form. I think that you can use the cattle injectable for chickens. And no, you should not put the injectable liquid into the water, as it wasn't meant to work that way.
It sounds like your chickens wing could be paralyzed, not broken. Do you know if she was ever vaccinated for Marek's disease? And is she still doing that mouth opening thing?
The dosage for Oxytetracycline is 1/8 teaspoon powdered Oxytetracycline per cup of drinking water for 7-14 days. During antibiotic treatment, do not give probiotics. Definitely give them afterward, though!