Burst release is characterized by which phenomenon?

• A. A delayed release due to coatings
• B. An initial rapid release of drug
• C. Complete release at once
• D. No release until pH changes

Answer: (B)

Burst release refers to an initial rapid release of drug from a dosage form. This occurs at the start of dissolution when a large amount of drug is immediately available at or near the surface, or when the matrix rapidly swells, erodes, or develops many fast-diffusion pathways. That early spike in release rate is what characterizes burst release, distinguishing it from slower or delayed phases that follow.

This explains why the statement describing an initial rapid release best fits the concept. It isn’t about a delayed release due to coatings, nor about the entire content being released at once, and it isn’t about release only occurring when pH changes. In practice, burst release often accompanies a subsequent sustained release, and its presence can be influenced by formulation factors like surface drug content, porosity, and polymer behavior.