Comparison study of different spherical crystallization methods of ambroxol hydrochloride

Orsolya Gyulai, P. Szabó-Révész, Z. Aigner

Research output: Article

5 Citations (Scopus)


Production of spherical crystals with an appropriate particle size is an important objective for active agents dedicated to direct tablet making (Diao et al. Nat. Mater. 2011, 10, 867-871; Tahara, K. et al. Cryst. Growth Des. 2015, 15, 5149-5156). The material chosen for our experiments, ambroxol hydrochloride, is such a solid compound. The optimal habit for the crystals of direct compressible active agents and additives includes sphericity, proper mean particle size, and appropriate surface. The main objective of the present work is to compare typical and nontypical spherical crystallization methods and to investigate their applicability for ambroxol hydrochloride. The particles were investigated by light microscopy, coupled with an image analyzator program, scanning electron microscopy, powder X-ray diffractometry and differential scanning calorimetry in order to obtain information about particle morphology, mean particle size, aspect ratio, roundness and potential polymorphic transitions. Powder rheology properties were also investigated. The typical crystallization method of quasiemulsion solvent diffusion was suitable for increasing mean particle size, but large-size spherical crystals did not form. Nontypical spherical crystallization methods (spherical agglomeration and the method of cooling with an alternating temperature profile) caused an increase in mean particle size and an improvement in aspect ratio and roundness. Powder rheology parameters of the spherical agglomeration products improved, too.

Original languageEnglish
Pages (from-to)5233-5241
Number of pages9
JournalCrystal Growth and Design
Issue number10
Publication statusPublished - jan. 1 2017


ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

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