I am sorry to hear your cat has escaped and you can't catch him. It must be scary for him, too, to be away from home and out of his normal routine.
I am a veterinarian and will do my best to help.
The problem with oral tranquilizers is that they are not very predictable in how quickly they work, and work differently in every cat. If the cat is stressed, they may not work at all until he gets away and calms down, out of your sight. Then if you grab him, he may still wake suddenly and bite or scratch.
We do have drugs that would knock him out enough to safely handle him, but they are by injection only.
The other problem is how are you going to get the tranquilizer? They are all prescription drugs, some are even controlled substances. Do you have a veterinarian who will work with you on this? Legally, only a veterinarian who has a client/patient relationship with you can prescribe tranquilizers.
If I were going to use tranquilizers, I would probably try 2.5 to 5 mg of acepromazine first. It is pretty safe, and should work in half an hour or so if you can keep up with him after he eats it, if he will eat it in food. However, you can only get it from your veterinarian.
If I were in this situation ( and I have been! I have had feral cats I cared for that I had to catch) I would use the trap. Since you lured him once with food, and if you are patient, and the only food available to him is in the trap, it should work. It might take a day or two; most cats are caught during the night.
If he will take the food you bring, the trap should work in a couple of days. You can't leave any other food out, only the food in the trap.
This is a hard situation for both of you. I have worked in shelters, and have helped feral cats myself for years, and the trap has always worked better than drugs for me. Let me know what else I can help with or answer.