I'm guessing it was dissolved in a volatile solvent so that cigarettes could dipped in it and the solvent would evaporate. If it smells like nail polish remover (acetone) I wouldn't drink it. On the plus side, you very well might be able to evaporate it and use the leftover powder if you have a milligram scale to measure it with.
It depends what the PCP was dissolved in. PCP itself is a powder, the liquid could be anything... If it's simply vodka or something harmless like that, yes you could drink it. But only the person who made that solution could tell you what liquid they dissolved the PCP in. If it smells like acetone, I'd give it a pass...