Codeine Elixir Extraction

[zera]

SWIM recently acquired two bottles of "Codeine Elixir" because he had his tonsils removed. This is a liquid version of the standard codeine tablet and is said to contain Codeine and Acetaminophen, the dosage being listed as "One to two teaspoons." SWIM understands the danger of Acetaminophen at higher doses and wishes to extract out the codeine.

The codeine extractions that he's found on the web say to place the pill in cold water and the aceaminophen should precipitate out. Well he doesn't really understand how codeine elixir works then, how is the aceta staying dissolved? Figuring that some other solvent besides H20 was being used in the elixir, he tried creating a solution that was 1 part elixir, 4 parts cold water and has kept it in the fridge for several days now. Nothing. Aceta hasn't dissolved out.

SWIM would appreciate it if someone could explain why this isn't working, and how to extract codeine from codeine elixir. He thanks you in advance for your responses.