The deterioration of medicines depends on various factors, including the product type, manufacturing process, quality of raw material, excipients, etc. Storage conditions also play a significant role. The shelf-life of a product is determined based on an average rate of deterioration under standard conditions of temperature, humidity, and light, as specified by the International Conference on Harmonisation (ICH) for the climatic zone where the medicine will be marketed. The expiry date is set to ensure that, under these conditions, the therapeutic effectiveness remains unchanged (at least 90% of the active ingredients must be present) and that there is no significant increase in toxicity.

Quality is defined as “the suitability of a pharmaceutical product for its intended use”. Each medicine intended for patient use must meet acceptable quality standards, including identity, purity, safety, and efficacy.

If a medicine fails to meet quality standards, the consequences can include:

• lack of therapeutic effect, potentially leading to prolonged illness or death,
• toxic or adverse reactions,
• wastage of financial resources, and
• loss of patient confidence

The quality of pharmaceutical products is affected by raw materials, the manufacturing process, packaging, transport and storage conditions. These influences may accumulate over time.

Stability is defined as “the extent to which a product retains, within specified limits, and throughout its period of storage and use (i.e., its shelf-life), the same properties and characteristics as it had at the time of manufacture” (USP 37).

EXPIRY DATE

Even when stored under proper conditions, medicines naturally deteriorate over time due to various processes.

In many countries, manufacturers are legally required to study the stability of their products under standardised and exaggerated environmental conditions. These studies help manufacturer select the optimal formulation, packaging, storage conditions, and ultimately determine an expiry date for each dosage form in its packaging.

The manufacturer’s expiry date refers to the expiry date of the unopened container.

The International Conference on Harmonisation (ICH) of Technical Requirements for the Registration of Pharmaceuticals for Human Use guidance document defines shelf-life as: “The period of time during which a pharmaceutical product is expected to remain within the approved shelf-life specification, provided it is stored under the conditions defined on the container label.”

Most pharmaceutical products have a shelf-life of 3 to 5 years. Products containing less stable substances are guaranteed for only 1 or 2 years.

Practical definition of shelf-life: the time between the date of manufacture and the expiry date.

For products sent to the field, the remaining shelf-life should be at least 1/3 of the total shelf-life. This means that 1/3 of the shelf-life should remain at the time the product is released from stock (Note: transport and handling may take additional time). For medical kits, which often only have 6 months of remaining shelf-life, they should only be ordered for emergency situations and not for EPREP stock.

The expiry date is clearly indicated on both primary (immediate) packaging and secondary packaging:

The UK MHRA advices pharmaceutical manufacturers that the term ‘expiry date’ means the product should not be used after the end of the month stated. For example, an expiry date of 12/2025 means the product should not be used after 31 December 2025.

On the other hand, the UK Royal Pharmaceutical Society (RPS) clarifies that when a product is labelled ‘Use by’ or ‘Use before’, it means the product should be used before the end of the previous month. For example, ‘Use by 06/2025’ means the product should not be used after 31 May 2025.

Caution

It is important not to confuse the date of manufacture with the expiry date (“Exp. Date”).

SHELF-LIFE - IN-USE SHELF-LIFE

Once a multi-dose drug container is opened, the exposure of the drug to environmental factor can shorten its shelf-life. Repeated opening and closing of the container may increase the risk of microbiological contamination and/or physico-chemical degradation. This risk is particularly high in bulk packaging and for certain medicines, such as anti-tuberculosis medicines, which are sensitive to temperature and humidity.

Some oral or injectable multi-dose products are provided in powder form tat needs to be reconstituted before use. After reconstitution, these products may undergo significant hydrolysis and thus have a limited shelf-life. Some may require refrigeration. For non-sterile medicines, always consult the manufacturer's leaflet for information on the in-use shelf-life. If such information is provided, follow the manufacturer’s guidance. If not, refer to the table below. Always record the date the product was opened and the updated expiry date on the medicine label or, if there is insufficient space, on the outer packaging.

Notes:

• Sterile products: any remaining content should be discarded immediately after the first use.
• Ointments: these are semi-solid, greasy preparations intended for application to the skin or mucous membranes.
• Creams: these are similar to ointments but contain an aqueous phase, making them more susceptible to microbiological contamination.
• Use of jars: a 100 g jar is intended for individual use. A 500 g jar can be used between multiple patients (e.g. in an hospital ward), but carres an increased risk of contamination.

BASIC STORAGE GUIDELINES

Proper storage is essential to maintaining the effectiveness and safety of medicines, as they can be sensitive to environment factors such as light (especially sunlight), oxygen, moisture, and extreme temperatures.

MSF follows manufacturer storage recommendations in alignment with WHO GDP Guidelines and MSF transport policy

• Keep medications in their original containers and outer packaging to protect them from sunlight.clearly
• Ensure the container is tightly closed to prevent exposure to air and moisture.
• Avoid opening containers before use.
• Do not remove desiccant packets (e.g. silica gel) from the packaging, as they help control moisture levels.
• Always check and respect the expiry dates - do not cover them with labels or writings.
• Store medicines according to the manufacturer's instructions.
• Follow the FEFO (First Expired, First Out) policy to manage stock.
• Organise cartons properly, ensuring that arrows are pointing upward and that identification labels, expiry dates, and manufacturing dates are visible.

Protecting products from sunlight:

• Cover windows or use curtains to block direct sunlight exposure.
• Store products in their original packaging and in cartons.
• Avoid storing or packaging products in direct sunlight.
• Use opaque plastic or dark glass bottles for products that are specifically sensitive to light.
• Maintain trees around the facility to provide natural shade, but regularly check for any branches that could potentially damage the facility.

Temperature storage for medical consumables:

• Store frozen: products that require storage at temperatures of -20ºC, such as certain vaccines, should be transported in a cold chain and stored frozen, typically for longer-term storage at higher-level facilities.
• Store refrigerated: store products at a temperature between 2°C and 8°C. This range is suitable for products that are heat sensitive but should not be frozen, such as vaccines. (For further information see Vaccines family).
• Keep cool: store products between 8°C and 15°C. This is for products that need to be kept cool but are not as temperature-sensitive as those requiring refrigeration.
• Store at room temperature: store products at a temperature between 15°C and 25°C. This is the standard temperature range for most of medical products.
• Store at ambient temperature: while not widely used, this term refers to normal storage conditions. Ambient temperatures typically means “room temperature”, ranging from 15°C to 25°C or up to 30°C, depending on local climate conditions. It implies storage in a dry, clean, and well-ventilated area.

Measures to reduce effects of humidity:

• Ventilation: ensure proper airflow by opening windows (with screens and bars) or using air vents. Store products on pallets and maintain space between pallets and walls.
• Secure lids: make sure all container lids are securely closed to prevent moisture from entering.
• Air circulation: use fans to improve airflow and reduce humidity build-up.
• Air conditioning: use air conditioning to control temperature and humidity levels.

Monitoring temperature and humidity in the medical storage area

• Manual monitoring: temperature and humidity should be manually checked twice a day, including on weekends
• Electronic monitoring instruments: use electronic devices for continuous monitoring that can record and track temperature and humidity over time, including minimum and maximum readings. To be monitored twice daily as well.
• Importance of manual checking: while remote monitoring systems are valuable, they should not replace the twice daily manual checks.

DETERIORATION OF MEDICINES

Medicines can deteriorate even if their expiry date has not been reached, particularly if they have been stored under conditions (temperature, humidity, and light) that differ from the conditions used during stability testing. Excessive or accelerated deterioration can also occur due to initial quality defects, such as manufacturing issues. Therefore, it is important to understand the normal appearance and characteristics of each medicine (colour, odour, solubility, consistency) in order to detect any signs of deterioration.

Some forms of deterioration may not show visible changes, but physical changes should be closely monitored. Any medicine showing signs of deterioration should be discarded, regardless of the expiry date. If any doubt, contact the pharmacist for advice.

Signs of deterioration:

• For all products: broken or ripped packaging, missing, incomplete or illegible labels.
• Liquids: discolouration, cloudiness (turbidity), sediment or unsuspended agglomerates in solutions, broken seal on bottles, cracks in ampoules, bottles or vials, moisture in packaging.
• Light-sensitive products: torn or damaged packaging
• Tablets: discolouration, crumbled tablets, tablets missing from blister packs, sticky tablets (especially coated tablets), unusual smells..
• Capsules: discolouration, sticky, crushed capsules
• Injectables: liquid that does not return to suspension after shaking.
• Tubes: sticky tubes, leaking contents, perforations or holes in the tube.
• Sterile products: torn or ripped packing; missing parts; broken or bent parts, moisture inside packaging; stained packaging.
• Foil packaging: perforation in packaging.
• Suppositories, pessaries, creams and ointments: melting, separation of phases.

Using expired or deteriorated drugs

MSF DOES NOT recommend the use of expired or damaged medicines due to the significant risk for the patient safety.

DESTRUCTION OF EXPIRED AND/OR DETERIORATED DRUGS

Check local regulations regarding medical waste management and environmental protection before implementing a disposal method.

Proper disposal is critical, as incorrect disposal can lead to serious negative consequences, including:

• water contamination
• the diversion and illegal resale of expired or inactive medicines
• toxic pollutants being released into the air due to improper incineration.

Particular attention must be given to the disposal of certain categories of pharmaceuticals, including controlled substances (e.g., narcotics and psychotropic drugs), anti-infective drugs, cytotoxic anti-cancer drugs, toxic drugs, aerosols, antiseptics, and disinfectants.

Normally, MSF should obtain authorisation for destruction from the relevant local authorities and ensure that the destruction method adheres to both WHO and MSF guidelines, as these may differ from local guidelines (if any). In specific cases, such as batch recalls, MSF must also obtain a certificate of destruction.