Most pharmaceutical inks since the early 1990s eliminate ethyl alcohol in favor of faster ink drying times, and may include methyl alcohol and isopropanol in addition to the traditional ingredients titanium dioxide and propylene glycol.
- U.S. Patent no. 3,258,347 - original pharmaceutical ink patent
- U.S. Patent no. 5,006,362, filed 9 April 1991 - eliminates ethanol in favor of faster ink drying times