https://doi.org/10.1351/goldbook.15227
Dry solid material consisting of many, usually free flowing, fine particles. Conventionally, the title "powder" should be restricted to powder mixes for internal use and alternative terms are used for other powdered formulations presented in this way, e.g., dusting powders, which are for external use.
Note: The term "powder", when used to describe a dosage form, however, describes a formulation in which a drug powder has been mixed with other powdered excipients to produce the final product.