Moisture Barrier Requirements for Orally Disintegrating Tablet (ODT) Packaging

Orally disintegrating tablets are among the most demanding dosage forms to package. Their porous, rapidly dispersing structure and hygroscopic excipients mean that even modest moisture ingress can change disintegration time, hardness, and taste masking performance.

Why ODTs Are So Sensitive

An ODT is designed to dissolve in the mouth in seconds without water. To achieve that, the tablet is manufactured with a highly porous internal structure and typically includes superdisintegrants and sugar alcohols.

The consequences for packaging are direct:

• The porous structure presents a large surface area for moisture adsorption
• Many common excipients are hygroscopic and soften or swell as they take up water
• Small changes in moisture content shift disintegration time — the primary quality attribute
• Packaging opening and reclosing behavior matters more than for standard tablets, because patients often take a single dose from a multi-cavity pack

Required Barrier Performance

In practice, ODT packaging specifications usually call for WVTR values at or below 0.1 g/m²/24h, and often require near-absolute protection.

Cold-form aluminum is the structure of choice for most ODT products. It provides an aluminum barrier on the forming side with a polymer or aluminum lidding web, giving both moisture and light protection.

For products where PVC-free packaging is required, PVC-free cold-form aluminum delivers the same barrier level without a PVC layer in the structure.

Lidding Selection

The lidding web is as important as the forming film. For ODTs, peelable aluminum lidding with a heat seal lacquer is common because it opens cleanly without pushing the tablet out of the cavity.

Key parameters to verify:

• Seal strength across the specified machine range, not just at the nominal set point
• Peel behavior after storage at elevated temperature, which can strengthen the seal
• Compatibility of the lacquer with the forming film under your line conditions

Verifying the Specification

Before committing to a structure:

1. Run stability studies at the climatic zone conditions of your target markets rather than a single condition. 2. Test in the actual pack format, including any secondary carton, since secondary packaging contributes additional barrier. 3. Include in-use testing that simulates patients opening and reclosing the pack.

For products intended for hot-humid markets, tropical-grade aluminum structures are worth evaluating alongside standard cold-form material. Our technical team can help match a structure to your stability data — contact us to discuss your formulation.