pH-Induced precipitation behavior of weakly basic compounds: determination of extent and duration of supersaturation using potentiometric titration and correlation to solid state properties.

Purpose: To examine the precipitation and supersaturation behavior of ten weak bases in terms of the relationship between pH-concentration-time profiles and the solid state properties of the precipitated material.

Methods: Initially the compound was dissolved at low pH, followed by titration with base to induce precipitation. Upon precipitation, small aliquots of acid or base were added to induce slight subsaturation and supersaturation respectively and the resultant pH gradient was determined.