CRYSTALLISATION OF PARACETAMOL FROM PURE AND P-ACETOXYACETANILIDE (PAA) DOPED SOLUTIONS

摘要

Studies have been made of the bulk crystallisation of paracetamol (acetaminophen)rnfrom aqueous solutions in the presence and absence of the impurity pacetoxyacetanilidern(PAA) under a range of growth conditions and impurity contents.rnDistinct changes in morphology can be engineered for the pure material resulting inrncrystals ranging from columnar (dominant {110} ) at low supersaturating to tabletlikern( dominant {001} ) at high supersaturations. Additions of PAA arrested therndevelopment of the {110} faces and all crystals were of a comulnar habit (dominantrn{110} ). Over the range of supersaturations examined ( 24 -86%), the aspect ratio ofrnthe crystals changed by a factor of 0.5x along the [001] direction. In parallel, therncrystals suffered an increase in incorporated impurity and defect content. It is shownrnthat the noted changes are likely to have a major effect on the downstreamrnprocessing of this material.