Polymorphism of pindolol, 1-(1H-indol-4-yloxyl)-3-isopropylamino-propan-2-ol

Abstract

Crystallization of pindolol from the melt was studied by differential scanning calorimetry (DSC) and polarized light thermomicroscopy (PLTM) in order to discriminate the polymorphic forms obtained by this method. The crystallization process originates one exothermic signal localized in two different well-defined temperature ranges. Fusion gives rise to overlapped curves, which were analysed by peak-fitting. The polymorphs were identified as the clusters formed with the values obtained for Tpeak of the component curves. Three polymorphic forms were exhibited by pindolol crystallized from the melt. Commercial pindolol presents only two of these forms.