What is the basis for the patent of nano anticancer drugs?

First of all, at present, there is only one kind of nano-selenium product, that is, selenium king nano-selenium. Secondly, Selenium King Nano-selenium is a health care product, which is approved by the Ministry of Health. It is not a medicine, so it has no patent for medicine. Wang Xi Capsule is the nano-level (nano-selenium) of intellectual property rights of Wang Xi Capsule, so it must be nano-selenium. In fact, many products now claim to be nano-selenium, but in fact most of them are organic selenium or inorganic selenium, not nano-selenium.