Final answer:
The National Drug Code (NDC) is used to specify the manufacturer, medicine, and package size of a drug. Other identifiers like NPI, USP, and DEA serve different purposes in healthcare and pharmaceuticals.
Step-by-step explanation:
The set of numbers used to indicate the manufacturer, medicine, and package size is the National Drug Code (NDC) number. The NDC is a unique 10-digit, 3-segment number assigned to each medication listed under the United States' Federal Food, Drug, and Cosmetic Act. The three segments of this code identify the manufacturer (or distributor), the product (including strength, dosage form, and formulation), and the packaging (size and type). Unlike the NDC, the National Provider Identifier (NPI) is for identifying individual healthcare providers, the United States Pharmacopeia (USP) sets standards for drug purity and quality, and the Drug Enforcement Administration (DEA) number is used by healthcare providers to write prescriptions for controlled substances.