This drug has applied for a patent for invention. What should we do next?

First of all, from the description of your problem, I deeply doubt your conclusion that "the examination and approval problem should not be big" I suggest that if you really have great expectations, find someone who really knows what to do.

Secondly, the pharmaceutical industry is a special industry and needs administrative examination and approval. Therefore, if you personally apply for a medical patent, then hurry to find a pharmaceutical company with relevant qualifications to talk about cooperation. If no one is willing to cooperate with you to develop your medicine, even if your conclusion that "the problem of approval should not be big" comes true, I am afraid there is basically nothing you can do except spend money to maintain it.

Zhong Kui talks about patent blog.