Headspace analysis evaluates the gases contained within a sealed pharmaceutical package to determine whether leakage or gas exchange has occurred. By measuring oxygen, carbon dioxide, or other gases inside the container, manufacturers can detect changes that may indicate compromised packaging. This method is particularly useful for products sensitive to oxidation or moisture. While headspace analysis does not directly measure leak size, it provides valuable information about packaging performance and product stability. When combined with deterministic container closure integrity testing technologies, it helps create a more complete packaging evaluation strategy.