Is it good to write some verses from the Quran and drink it for medicine?
The following discussion from a Quranic healing websight may be helpful for your further research:
Using legitimate ink: One of the successful tried methods is to use ink of saffron, as mentioned by our forefathers.
Ibn Al-Qayim said that the ancestors used to write Quranic verses and ask the one affected with the evil eye to drink it. Mejahid and Abi Qalabah claimed that it is alright to write the Quranic verses, wash it, and make the victim drink it. Ibn Abbas said that a woman was suffering from hard labor so she drank something of written and washed Quranic verses. Ayoub also stated that he saw Abi Qalabah write something of the Quran then washed it with water and made a man drink it to relieve his pain (Al-Tib Al-Nabawi-pp.170-171).