1. Chemical Raw Materials

　　Chemical raw materials are commonly used raw materials in drug preparation and can be obtained through synthesis, purification, and refining. For example, drugs like palmityl acetate and metformin require chemical raw materials for their preparation. These raw materials have advantages such as low cost and high production efficiency but also have disadvantages like high toxicity and low purity.

　　2. Plant Extracts

　　Plant extracts are also commonly used raw materials in drug preparation, usually using traditional Chinese medicinal herbs as raw materials. Because these herbs contain various active ingredients, special efficacy components can be extracted to prepare drugs. For example, plant extracts such as astragalus and ginseng are both medicinal materials and commonly used raw materials in both traditional Chinese and Western medicine preparation.

　　3. Animal Tissues

　　Animal tissues are also one of the raw materials in drug preparation, mainly used for preparing hormones, enzymes, proteins, and the like. For example, drugs such as insulin and urinary protein require animal tissues as raw materials. However, due to difficulties in sourcing and purification control, which affect the purity and quality of the drugs, their use is relatively limited.