Skip to Main content Skip to Navigation

The impacts of Spray Drying on the polymorphism of pharmaceutical and organic compounds

Abstract : The impacts of Spray Drying on the polymorphism of organic and pharmaceutical compounds have been investigated with the following compounds: pyrazinamide, olanzapine, 1,3-dimethylurea and N-methylurea. The experiments carried out by Spray Drying highlighted the flexibility of this crystallization technique to access to metastable forms. Co-spray drying tests of pyrazinamide with several excipients allowed to bring out the feature of two excipients on the crystallization of the active ingredient: -A polymer (polyvinylpyrrolidone) has enabled the crystallization of the δ form pyrazinamide. -1,3-dimethylurea (Form I) blocked the transition of the γ form of pyrazinamide to other polymorphic stable forms for two years of storage at room temperature. A surface action has been proposed to explain this fact. This work also presents the phase diagram between 1,3-dimethylurea and water in which several invariants including: metatectic, peritectic and stable and metastable eutectics are detected. Melt-quenching applied to the N-methylurea serves to characterize two new polymorphic forms at low temperatures, with a similarity in : the space group, the asymmetric unit and intermolecular bonds. A first order mechanism governed by cooperative shear movement was proposed to explain the good reversibility between these two forms despite the low diffusion at low temperatures (≈ -120 °C).
Document type :
Complete list of metadatas

Cited literature [23 references]  Display  Hide  Download
Contributor : Grace Baaklini <>
Submitted on : Tuesday, January 16, 2018 - 8:44:24 AM
Last modification on : Tuesday, February 5, 2019 - 11:44:33 AM
Long-term archiving on: : Monday, May 7, 2018 - 4:10:09 AM


thèse Grace Baaklini Doctorat...
Files produced by the author(s)


  • HAL Id : tel-01685045, version 1


Grace Baaklini. The impacts of Spray Drying on the polymorphism of pharmaceutical and organic compounds . Chemical Sciences. Université de Rouen, 2015. English. ⟨tel-01685045⟩



Record views


Files downloads