Helium leak detection is considered one of the most sensitive technologies available for identifying microscopic packaging defects. The method uses helium gas as a tracer, filling the container and measuring any escaping gas with a specialized detector. Because helium molecules are extremely small and chemically inert, they can pass through tiny openings that other gases cannot. This allows accurate measurement of leak rates in pharmaceutical packaging. Helium leak testing is widely used during package design, validation, and research stages to evaluate packaging performance and ensure that sterile drug products remain protected throughout their lifecycle.