Conditional Use of Expired Medical Materials


Most medical materials (e.g., drugs, fluids, disinfectant solutions, catheters, sutures, etc.) are imprinted with an expiration date. Beyond this date, the manufacturer does not guarantee the sterility, safety, or stability of the item. The use of expired materials without justification constitutes inadequate veterinary care under the Federal Animal Welfare Act. If scientific justification is provided, expired drugs (other than anesthetic, analgesic, and emergency drugs) may be used for non-survival procedures. Pain-relieving drugs may lose potency after the expiration date, resulting in unpredictable effects that can jeopardize humane animal use even in a non-survival setting.

Expired Materials

In keeping with recent federal guidelines all drugs and medical materials administered to any live vertebrate animals must be used within their expiration date (see applicable regulations below and note that Boston University policy covers all vertebrate animals). This includes fluids (such as saline & heparin) and materials (such as sutures). Therefore, please adhere to the following policy:

  1. Expired anesthetic, analgesic, or emergency drugs cannot be used on live animals under any circumstances.
  2. Other expired drugs or medical supplies cannot be used for any survival procedures, but can be used for non-survival procedures in cases where their use would not compromise the experiment. Scientific justification for their use must be approved by the IACUC.
  3. All drugs and sterile medical supplies must be marked with an expiration date in accordance with the following guidelines for expiration dating of medical materials.

Take the time to examine your inventory, and discard any outdated items.  Please be aware that the animal facility staff has been instructed to dispose of any and all materials housed within the animal facility that are beyond their expiration date as required by federal regulations.

Practical Guidelines

In cases where you reconstitute or aliquot drugs so that they are no longer in bottles marked with a manufacturers’ expiration date, please make sure to write the expiration date on each new bottle aliquoted from stock.

Expired drugs kept for in vitro use must be kept together in an area physically separate from all other medical materials and drugs that are used in live animals and must be marked with the expiration date.

When ordering drugs or materials that you don’t use up quickly, it is wise to inquire at the time of ordering about the expiration date of the lot that the company plans to send you, and make sure they don’t send old items that will be expiring soon. Alternatively, order in smaller amounts. Most common drugs and solutions have a shelf life of at least two years but there are exceptions. You may wish to check with others using the same drug and look into the possibility of sharing an order.

Dating of materials

In order to comply with federal regulations, all drugs and sterile medical devices intended for use in live animals must be marked with an expiration date.

Segregation of expired drugs and medical materials

All expired materials that are to be kept in inventory and used for non-survival procedures must be clearly and individually labeled as “Expired materials-for nonsurvival use only” and be kept together in an area physically separate from all other medical materials and drugs.


In order to assure that expired items are identified in a timely fashion so that they can either be discarded or appropriately labeled for conditional use, each research group must inspect their animal drug and material storage areas on a regular basis (i.e., every 30 to 60 days).

Manufactured drugs

Follow the manufacturer’s recommendations as printed on the bottle or package insert for expiration date and storage temperature. If drugs are placed into a container other than that supplied by the manufacturer, or are altered by diluting or mixing, the new container must be labeled with the name of the substance, the concentration, and an expiration date. Drugs that are altered from their original form (e.g. diluted, reconstituted, or mixed with other drugs) or aliquoted into a new container do not necessarily keep their original expiration dates. Dilution, mixing, or transfer to a new container may cause the drugs to lose potency or degrade due to a change in pH, buffering, atmosphere (some drugs are packed under special gases), or precipitation. In addition, drugs that are not kept in a sealed, sterile container may become contaminated and subject to bacterial degradation. Many drugs are incompatible with other agents and cannot be mixed.

Sterile medical devices and supplies

Pre-packaged sterile medical devices (e.g., sutures, sterile gloves, catheters, etc.) are distributed with an expiration date or with a statement to indicate that the contents are “sterile if the packaging is undamaged.” Medical devices marked with an expiration date cannot be used for survival procedures after that date, and should usually be discarded or, if applicable, re-sterilized. If retained past the expiration date, these materials must be stored in a separate location and labeled “Expired materials-for non-survival procedures only.”

Sterile surgical packs

Instruments or supplies sterilized by the investigator must be marked with an expiration date based on the date of sterilization. They must be marked with an external “process indicator” (e.g., autoclave or ethylene oxide tape) and must contain a sterilization indicator (usually a chemical indicator strip that indicates exposure to sufficient heat or ethylene-oxide to sterilize). Cloth-wrapped, paper wrapped, or Dennison® wrapped sterilized equipment has a shelf life of one month. Plastic-wrapped sterilized items (e.g., peel-packs) have a shelf life of 6 months.

Drug mixtures and non-manufactured drugs

If any drug or drug mixture is aliquoted into an unsealed or non-sterile container or is contaminated by non-aseptic technique, it has a maximum 24-hour expiration period unless it is immediately frozen. Frozen aliquots can usually be kept indefinitely (at –90°C), but then have a 24-hour shelf life once thawed.

IV fluids (e.g. normal saline, lactated Ringers) expire in 24 hours after opening if kept unrefrigerated, or may be kept up to a week if refrigerated.

If a drug is aliquoted unchanged into a sealed, sterile container (e.g. a red-top vacutainer, an empty sterile vial, a saline or sterile water bottle completely emptied of contents), it should keep its original expiration date (except if the drug is packaged in a special atmosphere such as argon or nitrogen).

If a drug is diluted or mixed with another compatible drug and put into a sealed, sterile container, it expires in one week (or at the earliest expiration date of the component drugs, whichever comes first).

Ketamine-xylazine rodent anesthetic cocktail (ketamine 10 mg/ml + xylazine 2 mg/ml in saline) when stored in a sterile sealed container, may be kept up to 1 month. This solution does not need to be refrigerated.

Others: Contact the IACUC Office or veterinary staff for guidance on materials not specifically addressed above.