Abstract
The effects of polyethylene glycol (PEG) 4000 dissolved in the crystallization solvent on the size of agglomerated crystals of phenytoin prepared by the spherical crystallization technique with a bridging liquid (i.e. isopropyl acetate) were investigated. The average diameter of agglomerated crystals at equilibrium, where the rates of growth and destruction of the agglomerates were balanced, decreased linearly with PEG concentration, since the PEG reduced the cohesive force tending to agglomerate the crystals of the bridging liquid by decreasing the interfacial tension and the wettability of the bridging liquid. Changes in the compaction of the crystal agglomerates and in the kinematic viscosity of the dispersing medium with increasing PEG concentration caused the agglomeration rate to change non-linearly with respect to PEG concentration.
