I need some info about the free-acid form of pentobarbital.
We have been using sodium pentobarbital for anesthesia in rats, but
recently ran out. Since we had some of the free-acid form in the lab,
I tried substituting that for the salt, adjusting for differences in
molecular weight. The acid is not soluble in water, but will readily
dissolve in 95-100% ethanol. Therefore, I administered about
38mg/kg of the free-acid dissolved in ethanol to 300g rats. This
produced a solid level of anesthesia and animals recovered nicely, and
they appeared healthy initially. However, all of the animals
receiving this preparation have died within 2 to 4 days of
administration.
Can anyone shed some light on what is going on?
Thanks.
