The main issues to be noted are as follows:
Second, the self-developed formula is not necessarily unknown to others, so the patent application must conform to novelty and creativity. In the vernacular, this formula has not been published in publications all over the world (such as books and magazines), nor has it been publicly used in China. Only by meeting this premise can we apply for a patent.
3. To obtain a patent, the formula and method must be made public. However, on the premise of publicity, and on the premise that ordinary technicians can realize this invention through your application documents, you can keep some technical secrets appropriately. Through this reservation, we can protect our own interests to a greater extent.
Fourth, the patent is valid. For your invention patent, it is 20 years from the date of application, which is enough for most patents.
Because the writing of application documents is complicated, many things will happen in patent application, and the average applicant doesn't know enough, so I suggest you find a patent agency to act as an agent. This is conscience advice.