A Review on Spherical Crystallization - The Novel Agglomeration Technique

Spherical crystallization is the novel agglomeration technique that can transform directly the fine crystals produced in crystallization process into a spherical shape. Methods for the preparation of spherical crystallization are spherical agglomeration, quasi emulsion solvent diffusion, ammonia diffusion method, neutralization method. In spherical crystallization good solvent, poor solvent and bridging liquid is used. Solubility profile, amount of bridging liquid, mode and intensity of agitation, residence time and temperature are to be optimized to obtain desired range of spherical agglomerates. Spherical crystals can be prepared into tablet form or compounded directly into pharmaceutical system without further processing such as granulation. Characterization of spherical crystals done by Optical microscopy, studied shape of the spherical crystals, X-ray powder diffraction, Electron scanning microscopy, Fourier Transform Infrared spectrometer, Differential scanning calorimeter. It is a particle design technique, by which crystallization and agglomeration can be carried out simultaneously in one step and which has been successfully utilized for improvement of flowability and compressibility of poorly compressible drugs, masking bitter taste of drugs and improving the solubility and dissolution rate of poorly soluble drug.