Capsule packaging looks like a solved problem from across the room. Just package the capsule like you'd package a tablet, right? Almost, but not quite. Capsules behave differently from tablets in two ways that matter for packaging design: they're more moisture-sensitive, and they're mechanically more fragile. Both push the packaging spec in directions tablets don't need.
The moisture problem
Most pharmaceutical capsules are made of gelatin or HPMC (a vegetarian alternative). Both materials absorb moisture from the surrounding air. Once the capsule shell takes on too much moisture, two things happen: the shell softens (so the capsule deforms), and capsules can fuse to each other (so the patient can't separate doses).
A tablet just sits there. A capsule reacts to its environment.
The packaging implication: capsules need higher moisture barriers than the typical tablet pack provides. PVC blisters that work for stable tablets often fail for capsules. PVDC-coated PVC is the minimum for most capsules. Alu-Alu cold-formed foil is preferred for hygroscopic API capsules in humid markets.
The mechanical fragility
Capsules don't break the way tablets do, they crush. Apply pressure to a capsule shell and it deforms instead of fracturing. That makes blister thermoforming trickier (the cavity has to be deep enough not to compress the capsule during sealing) and tertiary handling more careful (a heavily loaded carton in transit can crush capsules at the bottom).
In practice that means: bottle packaging often works better for capsules than for tablets, blister cavities for capsules need careful tooling, and shipping cases need to limit stack height.
Common capsule packaging formats
Blister wallets (cold seal)
PVDC-coated PVC for moderate moisture sensitivity, Alu-Alu for high moisture sensitivity. Cold seal wallet adds a paperboard outer layer for further protection and adherence design. Preferred format for unit-dose dispensing.
HDPE bottles with desiccants
Standard for high-count capsule products (30, 60, 90 capsules). Silica gel or molecular sieve desiccant absorbs moisture inside the bottle. Works well for OTC capsule supplements and some chronic medications.
Sachets
Multi-layer foil sachets for single-dose or special applications. Used for some specialty capsule formulations where a single dose ships separately.
When the capsule packaging conversation gets interesting
Two scenarios where capsule packaging needs more thought than usual:
High-humidity launch markets. A capsule that's stable in northern Europe might fail in tropical Southeast Asia without higher barrier packaging. Stability data has to be regional or global, not just home-market.
Liquid-filled capsules. Increasingly common for poorly soluble APIs. The liquid-filled shell is even more sensitive than a solid-filled capsule and often needs Alu-Alu plus a child-resistant overpack.
Where we help
We package capsule products in the same cold seal wallets we use for tablets, with the moisture barrier upgraded to PVDC or Alu-Alu where the stability data demands it. We also run capsule blister tooling that's specifically designed for capsule cavity geometry instead of generic tablet tooling.
If you have a capsule product launching and want to spec the packaging against the stability data, tell us about the API and target market. We'll come back with two or three configurations and a sample.
Request a free sample now!
