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IG017: Storage, Labeling, and Expiration of Multi-dose and Mixed Medical Materials Used in Animals

IACUC Guideline Number: IG017, Approved By: IACUC, Approval Date: 12/11/2025, Version: 6

This guideline outlines the proper labeling, storage, and maintenance of medical substances and materials used in animals to prevent inappropriate use of outdated items. It has been developed to ensure compliance with the Guide for the Care and Use of Laboratory Animals (8th Edition) and the NIH Guidelines on the PHS Policy for the Humane Care and Use of Laboratory Animals.

Definitions:

Expiration Date: Date provided by the manufacturer to indicate when substance is no longer acceptable to use. For expirations provided in Month/Year, the substance expires on the last day of the month listed.

Use by Date: The number of days for which the manufacturer recommends use of a product after it is first accessed (e.g. opened/punctured) or diluted. Also termed beyond use date.

Medical material: A non-bioactive substance intended for use in the diagnosis, treatment, or prevention of disease.  Examples include but are not limited to gauze, sutures, catheters, syringes, needles, etc.

Storage of Substances and Medical Materials:

Substances and medical materials are to be stored in accordance with the  manufacturer guidelines, or under conditions described in performance standard literature (e.g., at specific temperatures/refrigerated, protected from light, in glass container, etc.). 

Before each use, products should be visually examined for any changes; presence of precipitation, color change, or change in homogeneity indicate that a product may no longer be safe to use or effective even if it is not expired.

Expired Substances and Materials:

Expired substances and medical materials, including euthanasia agents, have unknown purity, potency, stability, and efficacy. Therefore, their use in survival surgical procedures is not consistent with adequate veterinary care.  It is NEVER acceptable to use expired anesthetics, analgesics or euthanasia drugs in an animal, regardless of whether the procedure will be survival or terminal.  It is the responsibility of the Principal Investigator (PI) to institute adequate inventory and laboratory management procedures to ensure that expired drugs and medical materials are promptly identified and properly disposed of.  All expired medical materials must:

  • Be stored separately from non-expired medical materials.
  • Be clearly labeled: “For use in terminal procedures only”.

For substance dilutions, preparations, or reconstitutions, prepared using sterile technique and under proper storage conditions, an expiration date of six (6) months from the date of preparation is recommended, unless otherwise scientifically justified in the animal protocol.  If any single component of the reconstituted substance has an earlier expiration date, that date should be used instead.

Drug bottle labeled Meloxicam, 5 mg/mL, Expires: 8/2027

Such materials should be labeled by name, drug concentration, and include the expiration date as soon as they are prepared (see example on the right). An item is considered expired the day after the month or date indicated on the label. (Example: Item labeled Aug. 2027 would be considered expired on Sept. 1, 2027.)  Expiration dates must be verified prior to all surgical procedures to ensure appropriate anesthesia and euthanasia. Per veterinary practice standards, the use of expired medical materials or substances (e.g., drugs, fluids, sutures, anesthetics, sedatives, analgesics) during any survival surgical procedure is unacceptable.

Expired materials (e.g., catheters, fluid lines, sutures) may be used in nonsurvival procedures when the animal is anesthetized and euthanized without recovery. These terminal procedures must not adversely affect the animal’s well-being or compromise scientific validity. Liquids, solutions, or drugs (e.g. analgesics, sedatives, anesthetics, fluids, or euthanasia solutions) CANNOT be used in non-survival surgery.

Use-By-Date:

Many medical products have both a standard “Expiration Date” and a “Use-By-Date” (i.e., “Beyond Use Date”) printed on the label or package.

  • Use-by-date should follow manufacturer recommendations.
  • If such recommendation does not exist, diluted (i.e., mixed or compounded) drugs have a maximum use-by-date of six months after mixing, as described above.
  • Extended use-by-dates for certain drugs may be acceptable when published performance standard studies have demonstrated extended maintenance of sterility and efficacy. Examples include:
    • Diluted carprofen may be maintained for up to six months when refrigerated, stored in glass vials, and protected from light (Xu et al., 2021).
    • Ketamine-acepromazine-xylazine may be maintained for up to six months when protected from light and stored in glass vials (Taylor et al., 2009).
    • Diluted buprenorphine may be maintained for six months when protected from light and stored in glass vials (DenHerder et al., 2017).

Proper Disposal of Expired Drugs:

Whether hazardous or non-hazardous, all expired or unwanted drugs are to be disposed of properly according to MSU Environmental Health & Safety (EHS) guidelines. Guidance for specific types of waste can be found at MSU Environmental Health & Safety - Waste. For additional questions, please contact EHS at 517-355-0153 (or ehs.msu.edu)

References

  • Federation of Animal Science Societies. Guide for the Care and Use of Agricultural Animals in Research and Teaching. 4th Champaign, IL: Federation of Animal Science Societies, 2020.
  • Green CJ, al. “Animal Anesthesia.” London: Laboratory Animals Ltd, 1979. p79.
  • National Research Council. Guide for the Care and Use of Laboratory Animals. 8th Ed.
  • Washington, DC: National Academies Press, 2011.
  • Public Health Service Policy on the Humane Care and Use of Laboratory Animals, Section IV., OLA
  • USDA APHIS Animal Care. Animal Welfare Act and Animal Welfare Regulations. 2008.
  • Taylor, al. “Beyond-use dating of extemporaneously compounded ketamine, acepromazine, and xylazine: safety, stability, and efficacy over time.” JAALAS. 2009 48(6): 718-726.
  • Xu, Jiajie J., Renner, Deanna M., & Lester, Patrick A. (2021). Strength and sterility of stock and diluted carprofen over time. Journal of the American Association for Laboratory Animal Science, 60(4), 470-474. doi: 10.30802/AALAS-JAALAS-20-000102.
  • DenHerder, Johnathan M., Reed, Ralph L., Sargent, Jennifer L., Bobe, Gerd, Stevens, Jan F., & Diggs, Helen E. (2017). Effects of time and storage conditions on the chemical and microbiologic stability of diluted buprenorphine for injection. Journal of the American Association for Laboratory Animal Science, 56(4), 457-461.