Primary moisture barrier · continuous

The HDPE bottle wall is the primary continuous moisture barrier. HDPE's crystalline polymer structure provides a highly tortuous path for water vapour molecules - dramatically slowing moisture ingress compared to PET or PP. The WVTR of the bottle wall is the single most important moisture protection factor for the stored capsules.

WVTR ≤ 0.5 g/m²/day at 38°C/90% RH

Tested to USP <661> container performance

White HDPE also blocks UV light degradation

Hermetic airtight seal at opening

The induction seal liner is an aluminium foil / foam / polymer laminate heat-sealed across the bottle mouth by an electromagnetic induction machine at the filling stage. When sealed, it creates a hermetic, airtight barrier across the bottle opening - zero moisture passage at the neck interface until the consumer removes it. This is the highest-priority seal point because the threaded cap interface alone allows significant vapour exchange.

Hermetic seal - zero moisture at neck interface

Consumer tamper evidence - foil must be broken

Applied by induction sealer at filling stage

Thread interface seal · reduces gap moisture

The child-resistant cap includes a PE foam or PE liner inside the cap body that compresses against the bottle rim when fully tightened - creating a secondary vapour seal at the thread interface. While not hermetic, this liner significantly reduces the air exchange at the cap-bottle thread junction compared to an unlined cap.

PE foam liner in cap reduces rim vapour exchange

Consistent compression across full 360° rim

Second barrier layer after induction seal removed

Active moisture absorption inside the bottle

A silica gel desiccant sachet placed inside the bottle at filling actively absorbs any residual moisture within the bottle headspace and any slow moisture ingress through the bottle wall or cap interface. Desiccants extend the effective moisture protection of the bottle system, particularly during distribution in humid climates (tropical, maritime, monsoon regions).

Silica gel sachet - 1g or 2g depending on bottle size

Absorbs residual headspace moisture at filling

Protects against moisture ingress in humid climates

Food/pharma-grade desiccant material

How child resistance is achieved

The push-down-turn (PDT) cap requires the user to simultaneously apply downward pressure on the cap while rotating it to open. This two-motion combination requires the hand strength and motor coordination of an adult - reliably preventing children under 5 from opening the bottle through standard turning or pulling actions alone. A tab on the inside of the cap engages a locking ramp on the bottle neck, which is disengaged only under downward pressure.

 Two simultaneous motions required: press + turn

 Locking tab disengages only under downward force

 Standard for pharmaceutical capsule packaging globally

ISO 8317 · 16 CFR 1700.20 · EN 28317

Child-resistant packaging certifications are market-specific regulatory requirements. Our CR caps are tested to ISO 8317 (international), 16 CFR 1700.20 (US PPPA - Poison Prevention Packaging Act), and EN 28317 (European standard). Each standard requires a child panel test (children aged 42–51 months) with a maximum opening success rate, and a senior adult panel test confirming accessibility for adults aged 50–70.

 ISO 8317: international child-resistant standard

 16 CFR 1700.20: US market (FDA/CPSC requirement)

 EN 28317: European CE market requirement

 Child panel test: ≤ 20% open success by children

Adult accessibility: ≥ 90% success by adults 50–70

Non-CR standard screw cap

For products aimed at elderly patients or where the buyer's regulatory review confirms CR packaging is not legally required, a standard non-CR screw cap with PE foam liner is available as an alternative. The non-CR cap provides the same moisture protection (PE foam gasket) without the push-down-turn mechanism. Specify at order stage based on your regulatory obligation and target consumer profile.

 Standard screw cap - no CR mechanism

Same PE foam moisture gasket

Suitable for elderly-targeted or non-CR-required products

Resin code #2 · widely accepted

HDPE resin code #2 is the second most widely recycled plastic globally - accepted by the vast majority of municipal recycling programmes in North America, Europe, and Asia-Pacific. The all-HDPE bottle and cap (cap in matching HDPE or PP) can be recycled together in the same stream. For brands with sustainability commitments, we can supply bottles with post-consumer recycled (PCR) HDPE content on production orders.

 HDPE #2 - most widely recycled plastic

Accepted by most municipal recycling streams

PCR (post-consumer recycled) content available