Ever wondered why your vitamin C serum loses potency before the expiration date? The culprit might be hiding in plain sight: your packaging material. For cosmetic formulators, the battle against oxidation and ingredient degradation starts with a simple choice—LDPE, HDPE, or EVOH? This isn’t just a plastic debate. It’s the invisible armor shielding your products from environmental threats. Today, we’ll dissect how these airless tube materials perform under the microscope of chemical stability, barrier strength, and eco-footprint. By the end, you’ll know exactly which material acts as your formula’s bodyguard (hint: it’s not a one-size-fits-all answer). Let’s dive into the lab data and real-world tests that’ll redefine your packaging strategy.