Use of Fluids and Diluted Drugs in Research Animals

Additional Guidance

Choose a dilution scheme that will result in a dosing volume that makes sense for your studies – neither too large a volume for the injection route into the animal, nor too small a volume for accurate dilution and delivery. This can be particularly important for anesthetics and analgesics. To avoid waste and contamination potential, only make up what is needed.

1. All drugs requiring dilution must be diluted and maintained using sterile technique.
   
   1. Use sterile saline or sterile water as the diluent unless otherwise documented in your approved animal protocol.
   2. When diluting a pharmaceutical grade drug solution from a septum-capped vial, sterile needles and syringes must be used to transfer drug solution and diluent into sterile empty vials (see image below). These vials 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.
      
   3. An exception to (b) would be if greater accuracy is required and/or if serial dilution is necessary, in which case dilutions may be made using sterile pipettes and pipettes and tubes under sterile conditions (i.e., in a tissue-culture hood), with the final solution being made into a sterile septum-capped vial.
      
   4. When making solutions and subsequent dilutions from solid drug material or when dilutions are made from non-pharmaceutical grade drug solutions, regular pipettes and tubes may be used, but the final solution for injection must be filter sterilized into a sterile septum-capped container.
      
      1. An exception to the requirement for use of a septum-capped container in such cases is when it is necessary to make multiple small-volume microinjections from a limited volume stock, over a short period of time (a few hours), and/or if blunt cannula injections are required. In such cases, smaller regular-capped sterile tubes may be used but care must be taken to reduce the chances of introducing contaminants by using new, sterile needles between injections.
      2. Another strategy would be to draw up the injectate into the dosing syringe in a sterile tissue-culture hood in the lab space; this syringe becomes both the sterile storage vial and the method for dosing. Change sterile needles with each animal injected.
2. 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 (see #4, below)
   5. Any additional information required by other entities, such as the DEA or ARC protocol
3. Practice aseptic technique with the multi-use vial to maintain sterility.
   
   1. Multi-use vials must be disinfected prior to each use by swabbing the rubber stopper with alcohol.
      
   2. A new, sterile, clean needle must be used when entering through the stopper into the multi-use vial.
4. If handled as described above, diluted drugs expire 30 days from dilution or on the expiration date of the original drug if that is earlier than 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 prior to the expiration date. If a lab has a method for validating efficacy of a drug or particular cocktail beyond the 30-day standard, or published data regarding stability is available, they can request an exception from the ARC, citing this justification..
5. 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 open date or expiration date must be written on the vial or bag to ensure that the container is discarded within 30 days. If a lab has a method for demonstrating sterility beyond the 30-day standard, they can request an exception from the ARC, citing this justification.
6. 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.
7. Drugs should be stored according to special requirements (e.g., amber bottles for light-sensitive drugs such as carprofen). Refer to packaging provided with the original stock container or information on the manufacturer’s website. At any time, if the user notices any cloudiness or bacterial / fungal growth inside the vial, it must be discarded immediately.