What's the difference between a patent for pharmaceutical ingredients and a patent for pharmaceutical compounds?

As the name implies, the difference between a pharmaceutical composition and a single drug.

Further subdivision, the patent of pharmaceutical ingredients is generally a combination of common drugs, such as the combination of various traditional Chinese medicines, and the creative review focuses on the combination (prescription ideas and efficacy); Patents of pharmaceutical compounds are generally Markush compounds (compounds of general formula), and creative examination focuses on the compounds themselves (structural properties of compounds, etc.). )