I don't know it looks like the only thing I would worry about is the diphenylhydramine, which is a sleep aid, causing drowsiness, but it is very possible to overdose on diphenylhydramine, so thats a negative. The other active ingredient looks like levomenthol, which most probably is the (L)-isomer of menthol. Menthol is a terpiene so I wouldent worry about it.

What would be good to read if you can find it is the paper:

Takeru Higuchi, Arthur Michaelis, T. Tan, and Arthur Hurwitz. "Ion Pair of Pharmaceutical Amines, role of dipolar solvating agents in extraction of dextromethorphan" Analytical chemistry.

It has info on the partition coefficient of DXM in a chloroform-water, liquid-liquid extraction,, but not in hexane.