Abstract
Phase separation of PAA by various cationic drugs has been investigated as a function of temperature, polymer and added drug concentration. There exists a temperature Tp at which the PAA-drug aqueous solution separates into two phases (liquid-liquid or solid-liquid). The Tp changes remarkably not only with PAA or added drug concentration, but also with the basic structure of drug molecules or valences of drug cations. The decreasing order of the Tp is O-benzoylthiamine>thiamine>N-methylephedrine>ephedrine>piperidine>N, N-dimethylaniline>N-methylaniline≒aniline>pyridoxine≒pyridine.
