Shelf life, storage and import checks for food supplements

How is a supplement's shelf life set?

A shelf life is set from stability data: the product is stored in its pack at controlled temperature and humidity, tested at intervals, and given the period over which it stays within its specification.

Two kinds of study are usual. Long-term testing runs at the storage condition of the intended market and continues through the period claimed. Accelerated testing runs hotter and more humid, at 40 °C and 75% relative humidity (RH) for six months in WHO's guideline, to show early how the product reacts to stress.

The reference methods were written for medicines. ICH Q1A(R2) addresses climatic zones I and II, with 30 °C/65% RH among its test conditions, and ICH left the conditions for zones III and IV to the regions and to WHO. WHO's guideline sets the long-term condition by the climatic zone of the market: 25 °C/60% RH for zone II, 30 °C/65% RH for zone IVa and 30 °C/75% RH for zone IVb. The long-term condition WHO's list gives each country is on the climatic zones page, and the packaging side of hot markets on blister packaging for hot and humid markets.

For supplements, each regulator decides how much of this it asks for. Two examples:

• Ghana. The Food and Drugs Authority's guideline for supplements, in its 2013 version, asks for stability data under WHO zone IVb conditions, with accelerated testing at 40 °C/75% RH for six months and long-term testing to the end of the shelf life, carried out in the container closure system in which the product will be marketed in Ghana.
• Saudi Arabia. In its guide to pre-registration evaluation for food products, the SFDA asks for a stability study based on the shelf life the manufacturer proposes, and caps the shelf life applied to the final pack at five years. In the section on capsule-packed products, which names tablets among them, the packing requirements also ask for a document that describes the packaging material and verifies its safety for use where the product is sensitive to heat, humidity or sunlight.

The standard shelf life of our products is 24 months, stated in the product documents. What a regulator asks to see behind a shelf life is set by that regulator, as the two examples show.

What the pack adds, and what it does not

The pack does not set the shelf life on its own; it decides how much moisture, air and light reach the product while the date runs.

A blister seals each dose in its own cavity until it is pressed out, so taking one dose leaves the others closed. A bottle is opened to all its remaining doses each time, and WHO's guideline treats that in-use exposure as a separate question for large multidose containers.

How much moisture gets through a blister depends on its film. WHO lists aluminium/aluminium blisters for solid dosage forms among impermeable containers, and for products in impermeable containers the humidity of the stability study is not a concern.

A blister is not automatically the stronger pack. A 2017 article in a pharmaceutical trade journal modelled one moisture-sensitive multivitamin tablet, with 100 mg of thiamine, at 30 °C/75% RH. It estimated the longest shelf life for a 60 cc bottle of 30 tablets with 2 g of silica gel desiccant (2.6 years), ahead of an aluminium/aluminium blister (1.7 years), a bottle without desiccant (1.2 years) and a PVC blister (0.5 years). It is a calculation for one product, not a measurement, and the article's figure is credited to a desiccant supplier; still, it shows that the formula and the pack decide together.

WHO also says that a storage statement on the label "should not be used to compensate for inadequate or inferior packaging".

How should supplements be stored and shipped?

Keep them within the storage condition printed on the pack, and in their cartons, along the whole route: warehouse, transport, port, the importer's store and the shelf.

A storage statement is set from the stability results, not the other way round. WHO's guideline for medicines ties each recommended label statement, such as "Do not store above 30 °C", to the long-term condition the stability study ran at. For a supplement, the statement that counts is the one on its own label.

The carton can be part of the protection. WHO's guideline lets the secondary pack count as part of the container closure system in a stability study if it has protective properties and the labelling clearly indicates that the product is to be stored in the primary and secondary packaging, as in "store tablets in blisters in the provided cartons". If your label says so, the blisters stay in their cartons through storage and on the shelf.

How hot do cartons get on a sea shipment?

In the shipments one study measured, hotter than the air outside. In a controlled study of medicine shipments to the tropics, published in the BMJ in 1992, the temperature inside the cartons ranged from minus 3.5 °C to 42.4 °C and ran 3 to 12 °C above the outside air; relative humidity inside ranged from 20% to 88%.

The study followed eleven essential medicines shipped by UNICEF from Copenhagen to Lagos, to Mombasa and on by road to Kampala, and to Bangkok. Three products lost 1.5% to 5.8% of their potency on the way, retinol (vitamin A) among them; the antibiotics tested were not affected.

Read it with care. It is a 1992 study of medicines, not supplements. Take it as a measured example of what a sea shipment can do to the cartons on board, not as a forecast for your shipment.

What it means for planning:

• Goods ship EXW by default, with FCA or DAP on request. Whoever books the freight, agree with them how long the cargo waits in port and where it stands.
• For a heat-sensitive product, ask your forwarder for a temperature logger to travel with the goods, so the importer can see the route as well as the papers.
• Plan arrivals so the goods do not wait in an open yard through the hottest months.

How much shelf life must be left when the goods arrive?

It depends on the country, and for supplements we found no confirmed rule. Some importing countries apply minimum remaining shelf life rules to food, among them Nigeria, Kenya and Egypt according to US government sources; check with your importer whether such a rule applies to supplements, which share of the shelf life it requires and from which date it is counted.

Then work back from the importer's answer to the latest date the goods can leave the plant. Dispatch, transit, customs and the importer's warehouse all use part of the shelf life, so size the order to what your distributor can clear and sell in the time that is left.

How must dates and batch numbers appear on the pack?

On the pack itself, and in some markets in a set format and language; a sticker added on arrival does not work everywhere.

• Saudi Arabia. As reported by the USDA for food, production and expiry dates are engraved, embossed or stamped in permanent ink on the pack or its original label, and stickers for the dates are not permitted. One pair of dates is shown: day, month and year when the shelf life is up to three months, month and year when it is longer. The label is in Arabic, and any other language stands beside it with the same content.
• United Arab Emirates. Under the food rules in the same series of USDA reports, the dates go on the original label or the primary pack in indelible ink, and dates printed only on stickers are not accepted. With a shelf life over three months, month and year may be used, and the date then means the last day of that month.
• Egypt. For products registered with the Egyptian Drug Authority, the registration guideline asks for the label data in Arabic and English on the outer and the inner pack, including the batch number and the production and expiry dates. For an inner pack made of aluminium, it says the product name, the pharmaceutical form and the company name or logo are sufficient; the full set, with the batch number and the dates, stays on the outer pack. Which Egyptian authority registers your product is for your importer to confirm.

Under those food rules, a 24-month shelf life falls in the month-and-year bracket in both Gulf countries.

On a blister run, the batch number and the expiry date are on the carton itself. The expiry date is printed when the carton is printed, or applied as the blisters are packed into the carton, so it does not go on as a sticker. The carton and label text is set in the languages the country of sale requires, to rules your importer confirms. Name the market in your enquiry, and we confirm how the dates and the batch number are applied to the pack.

What should a distributor check when the goods arrive?

Check that the goods match their papers and that the route has not used up the shelf life your market requires.

• The batch number and dates on the pack match the Certificate of Analysis and the specification for that batch.
• The remaining shelf life meets any rule your importer's authority applies.
• Where the food rules reported by the USDA apply, as in Saudi Arabia and the UAE, the dates are printed on the pack, not stuck on.
• Cartons are dry and undamaged, and the lidding foil over each blister cavity is unbroken.
• The storage condition on the label was kept on the way; if a temperature logger travelled with the goods, read its record.
• The languages and importer details on the pack are those the registration requires.

Then move the goods into storage that meets the label condition, and keep blisters in their cartons if the label says so.

Our part is the documents. Each batch comes with its Certificate of Analysis and specification, and copies of the plant's certificates with their numbers are sent on request. The brand owner or a local importer files the registration in the country where the product is sold; we do not.

What your product decides

Before you pick a pack or a route, the product and the market have already settled part of the answer. Each line below shows what it costs in time, in run size or in risk.

Questions buyers ask about shelf life and storage

Read more

Blister packaging for hot and humid markets · Climatic zones by country · Quality and batch documents