Riddell, D. L., Hyndman, T. H., Bowden, R. S. et al. 2023. Use of a low-calorie flavored gel to facilitate oral self-administration of analgesics in mice. JAALAS 62(2), 163–169.

The goals of this study were to determine whether mice would adapt to a low-calorie flavored water gel as their sole source of hydration and whether the addition of acetaminophen, tramadol, meloxicam, or buprenorphine to the gel would affect their intake. Water and gel intakes were measured during a 4-phase study, each of which lasted 1 wk: phase 1, standard water bottle only; phase 2, standard water bottle and a separate tube containing water gel; phase 3, water gel only; and phase 4, water gel containing an analgesic drug. Water consumption, corrected for body mass, was not different between male and female mice when water was available (phases 1 and 2). However, the total consumption of water and water gel was higher for females than males during phase 2, and female mice consumed more gel than males during phase 3. When male and female data were combined, total corrected water intake was not different among the first 3 phases of the study. Gel intake did not change significantly after the addition of acetaminophen, meloxicam, buprenorphine or tramadol as compared with untreated water gel. These data suggest that drugs presented in the low-calorie flavored water gel may be a viable alternative to injection or gavage for the administration of analgesic drugs.