Export packaging · Climatic-zone stability
The short answer
Climate-zone stable packaging is packaging validated to the storage conditions of the destination market’s WHO climatic zone, not to the temperate condition most stability data defaults to. Most of Puizer’s East and West African buyer countries are held to a long-term stability condition of 30°C at 65–75% relative humidity — Climatic Zone IVa or IVb — against the 25°C/60% RH used for Zone I/II markets like the UK or continental Europe. A pack and a shelf-life claim proven only against the milder condition has no data behind it for the shelf it will actually sit on.
Compiled September 2026. Climatic-zone definitions and country-level long-term testing conditions are drawn from the WHO Expert Committee on Specifications for Pharmaceutical Preparations (Annex 2, WHO Technical Report Series No. 953, and Annex 10, WHO Technical Report Series No. 1010) and ICH Q1A(R2) — see References. Packaging-material comparisons reflect established pharmaceutical-packaging engineering practice rather than a single cited source.
This one sits alongside our Pharmaceutical Export to Africa guide and the export documentation checklist — both cover what gets a shipment out of India and through customs. This post covers something upstream of both: whether the product survives to be sold once it arrives, and whether the stability dossier behind it actually supports the market it’s landing in.
What “climate-zone stable” actually means
Pharmaceutical stability testing has run on a four-zone model since it was first proposed by Paul Schumacher in 1972 and refined by Wolfgang Grimm through the 1980s and 90s, later adopted by WHO’s Expert Committee on Specifications for Pharmaceutical Preparations.[2] The idea is simple: instead of testing every product against every country’s actual climate, the world is grouped into four zones by mean kinetic temperature and humidity, and each zone gets one long-term storage condition to test against.
Zone IV — hot and humid — was later split into IVa (hot/humid) and IVb (hot/very humid) because manufacturers and regulators couldn’t agree on a single condition for markets as different as coastal West Africa and the Gulf.[1] ICH’s own harmonisation attempt on this point, Q1F, was withdrawn in 2006 precisely because Zone III/IV conditions vary enough by region that ICH left the decision to WHO and to national regulators.[3]
| Zone | Climate | Long-term test condition | Confirmed for |
|---|---|---|---|
| I | Temperate | 21°C / 45% RH | Northern Europe, Canada |
| II | Subtropical / Mediterranean | 25°C / 60% RH | UK, most of continental Europe, Japan, US |
| III | Hot and dry | 30°C / 35% RH | Parts of the Middle East |
| IVa | Hot and humid | 30°C / 65% RH | Kenya, Uganda, Rwanda, Ethiopia[1] |
| IVb | Hot and very humid | 30°C / 75% RH | Nigeria, United Republic of Tanzania, Ghana[1] |
Swipe to see all columns →
India itself is confirmed at 30°C/70% RH — its own long-term condition, distinct from either IVa or IVb.[1] That gap matters more than it looks: a dossier built purely on India’s home stability data doesn’t automatically demonstrate compliance with Kenya’s or Nigeria’s stated condition, even though all three sit in the same general “hot and humid” family.
Where this goes wrong
The common failure isn’t a product that’s badly made — it’s a product whose stability data was generated against the wrong condition and never revalidated. A tablet cleared on 25°C/60% RH data (Zone II) has zero data supporting its behaviour at 30°C/75% RH after six weeks in an uncooled bonded warehouse in Lagos or Dar es Salaam. If it fails, it fails on the distributor’s shelf or in a regulator’s post-market sample — not in a lab where it can be caught and fixed.
What climate-stable packaging actually consists of
“Better packaging for hot climates” usually means one or more of four changes, applied in proportion to how moisture-sensitive the API actually is — not applied uniformly as a default, which mostly just adds cost without adding protection where it isn’t needed.
Layer 01Primary barrier film
The blister or bottle wall itself.
- Plain PVC: lowest cost, lowest moisture and oxygen barrier — fine for stable, non-hygroscopic products in temperate markets
- PVDC-coated PVC or PVC/Aclar (PCTFE) laminates: meaningfully higher barrier, still transparent, a common mid-tier choice for Zone III/IVa products
- Cold-form Alu-Alu: near-total moisture, oxygen and light exclusion — the reference choice for moisture-sensitive APIs or long dwell-time distribution into Zone IVb
Layer 02Bottle and closure
For bulk tablets, capsules and dry syrups.
- High-density polyethylene (HDPE) bottles with induction-sealed (heat-induction foil liner) closures rather than a plain screw cap
- Silica gel or clay desiccant canisters sized to the fill volume, not a token single sachet
- Cap torque and liner specification validated at the destination’s accelerated condition, not just at ambient lab conditions
Layer 03Export / tertiary pack
What protects the primary pack in transit and warehousing.
- Moisture-resistant carton board and shrink-wrap rather than standard corrugate alone
- Palletisation and stacking specs suited to non-climate-controlled sea freight and port dwell time, which is often the harshest single stretch of the journey
- Labelling and adhesives selected to survive sustained high humidity without lifting
Layer 04Documentation match
The paper trail behind the physical pack.
- Stability dossier generated at, or bracketing, the destination’s confirmed long-term condition — not just India’s home condition
- Shelf-life claim on the COA and label consistent with the data actually held for that market
- Container-closure system description in the CTD dossier matched to what’s physically shipped, so registration review doesn’t stall on a mismatch
Validating the pack: what the stability study actually has to show
Under ICH Q1A(R2), the base long-term/accelerated protocol runs long-term data at the market’s confirmed condition alongside six months of accelerated data at 40°C/75% RH, with intermediate testing at 30°C/65% RH triggered if the accelerated data shows significant change.[3] For solid dosage forms packed in a primary container that’s already a strong water-vapour barrier — cold-form Alu-Alu being the clearest example — regulators generally don’t require additional testing at the more extreme humidity conditions, because the pack itself is doing the barrier work the test would otherwise be checking for.[2]
Where a product doesn’t hold up at the required condition, WHO’s guidance sets out the available responses in order: shorten the shelf-life or retest period, move to a more protective container-closure system, or add cautionary storage statements to the label.[2] In practice, the second option — upgrading the pack rather than shortening the shelf life — is usually the better commercial outcome for an export product competing on shelf life against other suppliers.
Tip
When you send an RFQ, name the destination countries, not just “Africa” or “export.” Nigeria and Tanzania are confirmed at 30°C/75% RH; Kenya, Uganda and Rwanda are confirmed at 30°C/65% RH.[1] That difference can be the gap between a standard PVDC/PVC pack being sufficient and needing to move to Alu-Alu — and it changes the price and lead time you should expect to be quoted.
How this shows up in manufacturing
At Puizer’s WHO-GMP facility in Sonipat, packaging specification is treated as part of the product’s regulatory strategy, not an afterthought decided after formulation is finished. That means running stability studies at conditions matched to the buyer’s actual destination markets, specifying the primary barrier (PVC, PVDC-coated PVC, or cold-form Alu-Alu) against the API’s known moisture sensitivity rather than defaulting to whichever line has spare capacity, and building the COA, stability data and CTD container-closure description as one consistent package before a dossier goes to a distributor or a national regulator. For a private-label or third-party manufacturing order, that packaging conversation is one we have before formulation is locked, not after the first shipment comes back with a complaint.
Climatic Zone IVb is WHO’s classification for “hot and very humid” regions, tested at a long-term stability condition of 30°C and 75% relative humidity. It’s a subdivision of the original Zone IV, split from Zone IVa (30°C/65% RH, hot and humid) because manufacturers and regulators found a single Zone IV condition didn’t adequately cover the range of hot, humid climates worldwide. Nigeria, the United Republic of Tanzania and Ghana are among the WHO Member States confirmed at the IVb condition.
No. India’s confirmed long-term testing condition is 30°C/70% RH, which sits between the IVa (30°C/65% RH) and IVb (30°C/75% RH) conditions used by most East and West African markets. A dossier built only on India’s home condition doesn’t automatically demonstrate the destination market’s stated condition, so exporters should check the specific country’s confirmed condition rather than assuming the home data transfers directly.
Yes, materially more, because the tooling, material and machine platform are all different from a standard thermoformed PVC blister line. Whether that premium is justified depends on the API’s moisture sensitivity and the shelf-life claim you’re trying to support, not on the destination climate alone — a stable, non-hygroscopic product often does fine on a PVDC-coated PVC pack even into Zone IVb, while a hygroscopic or oxidation-sensitive API may need Alu-Alu regardless of destination. The decision should follow the stability data, not a blanket default.
Under the standard ICH/WHO protocol, accelerated data (40°C/75% RH) takes a minimum of six months, run in parallel with long-term data at the market’s confirmed condition, which continues for the duration of the intended shelf life. There’s no way to compress the accelerated window and still support a full shelf-life claim — a shorter interim claim, based on partial data, is the usual workaround while the full study continues.
Not automatically. Zone II data (25°C/60% RH) doesn’t demonstrate performance at the 30°C/65–75% RH conditions confirmed for most East and West African markets. If the product hasn’t been tested at the higher condition, the options are to generate new destination-matched stability data, or to move to a more protective container-closure system and support the claim that way — both routes WHO’s own guidance treats as legitimate responses to a shortfall.
Specifying packaging for a specific market?
Tell us the destination countries and the API’s known sensitivity, and we’ll scope the pack, the stability protocol and the dossier documentation together — before formulation is locked in.
References
- World Health Organization. Stability testing of active pharmaceutical ingredients and finished pharmaceutical products: stability conditions for WHO Member States by region (update, March 2021). Annex 2, WHO Technical Report Series, No. 953. Geneva: World Health Organization. Available from: cdn.who.int. Accessed September 2026.
- World Health Organization Expert Committee on Specifications for Pharmaceutical Preparations. Annex 10: Stability testing of active pharmaceutical ingredients and finished pharmaceutical products. WHO Technical Report Series, No. 1010, fifty-second report. Geneva: World Health Organization; 2018. Available from: database.ich.org. Accessed September 2026.
- International Council for Harmonisation. Q1A(R2): Stability Testing of New Drug Substances and Products. ICH Harmonised Tripartite Guideline, Step 4, 6 February 2003. Available from: database.ich.org. Accessed September 2026.
Climatic-zone classifications and confirmed long-term testing conditions are set by WHO and national regulators and are reviewed periodically — confirm the current condition for your specific destination market before finalising a stability protocol or packaging specification. Packaging-material guidance here is general; the correct specification for a given product depends on its own stability data and formulation.
