An active ingredient is a chemical that is usually a small molecule produced in chemical synthesis processes, while a biological drug is based on components and processes derived from animal or fermentation and/or tumor microorganisms/cells.
1. Molecular weight: Biological drugs, such as peptides and proteins, are huge molecules compared to chemical drug molecule sizes.
2. 3D Structure: Proteins, unlike chemical drugs, have a 3D structure that affects their function.
3. Manufacturing process: The production process of a chemical drug is synthesized for specific molecules in a known process. The biological drug production process, on the other hand, is much more complex and may result in high variability of the final product.