It's not a coated tablet and could be divided to whatever amount needed(at least I do so). BTW its also manufactured in 5mg tablets too but I suspect price difference would be not 2 times less and well worth the effort of biting half a pill off. No need to be precise here as our messy biology would make bioavailability different even for ideally equal tablets.
Back to the thread topic:
I found another interesting study
Sirolimus and everolimus in kidney transplantation.
http://sci-hub.tw/10...dis.2015.05.006
1. Looks like bioavailability is similar
Sirolimus Cmax (SD) of 40.5 +-22.2 mg/L
Everolimus Cmax (SD) of 45 +-21 mg/L (both for 2.5mg oral dose)
Sirolimus is more bioavailable with food
https://www.ncbi.nlm...pubmed/10579146
while Everolimus is less
https://www.ncbi.nlm...pubmed/11837553
It would be interesting to know whether Everolimus increase its bioavailability when taken sublingually. Its one of the suggested routes of administration for Tacrolimus and it's recommended to cut the dose in half for it, meaning its 2x more bioavailable.
One probable advantage is that sublingual route could mean its more available to the brain.
2. The study notes that there is no method of measuring mTOR inhibition quantitatively to compare two drugs, having that this is a pretty recent(2015) study means that we would not have this information for some time.
3. Due to different pharmacokinetics, two drugs accumulate differently.
Sirolimus: In studies in rats, considerable accumulation of sirolimus in
the heart, kidney, intestine, and testes was found, although
whether this is the same in humans is not known
Everolimus: Animal experiments showed a high affinity of everolimus for thymus,
lungs, gallbladder, cerebellum, kidneys, and spleen. Data in
humans are not available.
Everolimus tissye affinity looks more favorable to me, but as I take it myself I definitely feel some urge to feed my confirmation bias)