Which test is used to confirm the identity of a drug substance?

Which test is used to confirm the identity of a drug substance?

• A. Special method
• B. Pharmaceutical assaying
• C. Identification test
• D. Pharmacopoeial test

Answer: (C)

To confirm what a drug substance actually is, you use an identification test. This qualitative test checks for features that are unique to the substance—such as a specific spectrum, melting point, or characteristic chemical reaction—and compares them with a known reference. The goal is to prove the sample matches the claimed substance, not to measure how much is present or to perform a general check of various properties.

A special method is too vague because it doesn’t specify identity. Pharmaceutical assaying focuses on determining quantity or potency, not identity. A pharmacopoeial test is a broad category that includes many different tests, of which the identity test is the one explicitly designed to confirm identity.