1. Choose a dilution scheme that will result in a dosing volume that makes sense for your studies – not too large a volume for the injection route into the animal, nor too small a volume for accurate dilution and delivery. To avoid waste and contamination potential, only make up what is needed.
  2. All drugs requiring dilution must be diluted and maintained using sterile technique.
    1. Use sterile saline or water as the diluent.
    2. Sterile needles and syringes must be used to transfer drugs and diluents into sterile empty vials (see image below). These are available from the DLAM Pharmacy, DLAMPharmacy@mednet.ucla.edu, in both clear and amber glass, or may be purchased from any UCLA-approved vendor. Use a size appropriate for the volume of liquid.
      Sterile Empty Vial
    3. Open-mouthed containers such as Eppendorf or centrifuge tubes must not be used, as these cannot be kept sterile; the lack of a rubber stopper does not permit sterile entry of the needle into these types of containers.
      Eppendorf and centrifuge tube
  3. All diluted drugs must be labeled with the following information:
    1. Drug name
    2. Name of person who made the dilution
    3. Drug concentration
    4. Expiration date, which is thirty (30) days after the dilution date, provided this does not pass either the expiration date of the drug listed on the original container or the sterile diluent (see #5, below)
    5. Any additional information required by other entities, such as the DEA or ARC
  4. Practice aseptic technique with the multi-use vial to maintain sterility.
    1. Multi-use vials should be disinfected prior to each use by swabbing the rubber stopper with alcohol.
      vial stopper swab alcohol
    2. Always use a new, sterile, clean needle when entering through the stopper into the multi-use vial.
  5. If handled as described above, diluted drugs expire 30 days from dilution. A 30-day expiration date minimizes the likelihood of contamination while allowing for compound stability. If the solution turns cloudy or discolored or becomes ineffective, it must be discarded.
  6. If handled as described above, multi-use fluid bags or vials (such as 0.9% saline) used for subcutaneous fluid administration or drug dilution must be discarded within 30 days, to minimize the risk of contamination due to multiple needle entries into the stock bag or vial. The expiration date must be written on the vial or bag.
  7. If handled as described above, stock solutions that are divided into aliquots but are not diluted expire at the same time as the original stock solution. The expiration date must be written on the aliquot.
  8. Drugs should be stored according to special requirements (i.e. amber bottles for light-sensitive drugs such as carprofen). Refer to packaging provided with the original stock container, or on the manufacturer’s website.


Assessment of Sterility in Fluid Bags Maintained for Chronic Use
Authors: Matthews, Kristin A; Taylor, Douglas K
Source: Journal of the American Association for Laboratory Animal Science, Volume 50, Number 5, September 2011, pp. 708-712(5)

Beyond-Use Dating of Extemporaneously Compounded Ketamine, Acepromazine, and Xylazine: Safety, Stability, and Efficacy over Time
Authors: J Taylor, Brett; Orr, Steven; Chapman, Jennifer; Fisher, Diana
Source: Journal of the American Association for Laboratory Animal Science, Volume 48, Number 6, November 2009, pp. 718-726(9)

Website: Veterinary Information Network

Revised 7/2019