Q. See question above. Can one cut the pill in half with a knife? If exact measurement is needed, can it be cut with a pill cutter?
A. Horav Shlomo Miller's Shlit'a opinion is that a pill cutter cannot be used on Shabbos.
(See question 2268 regarding Tevila in a Mikva for the cutter).
Rabbi A. Bartfeld as revised by Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu Shlit'a