Adequate pain management is essential and mandatory in laboratory animals subjected to surgery and other procedures or chronic conditions that cause distress. Insufficient analgesia compromises animal welfare and can lead to unnecessary suffering and inaccurate experimental results due to the animals physiologic and endocrine response to pain. A recent survey conducted by ClearH2O among AALAS members showed that the majority of lab personnel use injections as the principal route of administration of pain management drugs. However, the injection procedure itself inflicts discomfort and stress to laboratory animals due to handling and restraint, as well as the inherent pain from the injection.
Nutella® has been used as a masking agent for bitter medications
Providing laboratory animals with highly palatable alternatives for effective orally consumed drug administration has many benefits. For years, scientists, veterinarians, and other professional animal care providers have used a chocolate hazelnut paste, Nutella®, to deliver pain medication to lab animals. As an example, buprenorphine is a bitter tasting opioid used to treat acute and chronic pain. Even in humans, buprenorphine’s very bitter taste has caused patients to discontinue their treatments. Similarly, mice commonly refuse to self-medicate when presented with off-tasting oral medications. A number of studies have reported that using Nutella® can be an effective oral delivery method for buprenorphine to mice and rats.
MediGel® Hazelnut is a better alternative for medication delivery
A disadvantage of Nutella® is its high fat (29.7%) and sugar (56.7%) content, and the presence of theobromine found in chocolate that can be toxic to mice and rats. ClearH2O has developed and is now making commercially available a healthier alternative to Nutella®, MediGel® Hazelnut, specifically formulated and packaged for use with laboratory mice and rats. MediGel® Hazelnut contains 8.2% fat, 44.6% sugar and is free from chocolate and theobromine. Purified ingredients used include cane sugar, dry milk, hazelnut butter, cocoa butter and carob powder, giving MediGel® Hazelnut a highly palatable flavor that masks the unpleasant taste of various medications. MediGel® Hazelnut is eagerly consumed by laboratory animals and its paste like texture allows for easy hand-mixing of liquid or powder medications and other target ingredients.
Efficacy studies reveal that MediGel® Hazelnut is an efficient way to deliver Buprenorphine
At the University of New England, MediGel® Hazelnut was tested as a carrier to deliver buprenorphine to Sprague Dawley rats. Rats were subjected to a plantar incision surgery to induce pain and were then randomly assigned into 4 groups:
- Standard food and water (control)
- Standard food and water + injection
- MediGel® Hazelnut (control)
- MediGel® Hazelnut + buprenorphine
Rats were habituated to the gel 7 days before surgery. Antinociceptive efficacy was assessed by determining tactile thresholds (Von Frey Assay) and thermal latencies (Hargreaves test). As reported in the two graphs above, results show that buprenorphine mixed in and delivered through MediGel® Hazelnut prevented the development of thermal hyperalgesia and tactile allodynia associated with the plantar incision, and proved to be an effective way to deliver buprenorphine.