| Abstract: | Glycine crystallization during spray drying has been investigated on a laboratory scale. In order to obtain different polymorphs the experiments have been performed at different hot air temperatures, concentrations, different flow of the solution and spraying air. The obtained crystals were analyzed by means of X‐ray powder diffractometry, differential scanning calorimetry and the Fourier transform infrared spectrometry. Crystallization mostly resulted with a mixture of α‐ and β‐glycine with a small amount of γ‐glycine. The glycine polymorphism is affected by the drying air temperature, concentration and the flow of the solution, as well as the spraying air flow. Decrease of the drying air temperature and increase of the solution flow rate causes the increase of the quantity of β‐glycine. At room conditions, β‐glycine spontaneously transforms into thermodynamically more stable α‐glycine. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) |
