title: Solid state transformations in consequence of electrospraying--a novel polymorphic form of piroxicam.
abstract: The aim of the research was to verify that electrospraying of piroxicam yielded a new polymorphic form of this drug. In the experiments, piroxicam was dissolved in chloroform and the solution was atomised electrostatically. Subsequently, the charged droplets were neutralised and dried. The solid drug particles were collected and analysed by scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, high performance liquid chromatography, and infrared and Raman spectroscopy. The X-ray diffractogram measured for the electrosprayed piroxicam particles did not match with any of the known piroxicam crystal structures (Cambridge Crystallographic Data Centre). The variable temperature X-ray diffraction showed that the structure recrystallised completely into piroxicam polymorphic formI during heating. No degradation products or solvate removal was detected by high performance liquid chromatography and thermal analysis. The infrared and Raman spectra of the electrosprayed piroxicam were compared to those of formI, and some notable differences in the peak positions, shapes and intensities were detected. The results indicate that electrospraying leads to piroxicam crystallisation in a currently unknown polymorphic form.
authors.affiliation: Laboratory of Industrial Physics, Department of Physics and Astronomy, University of Turku, Turku, Finland. Electronic address: mhnyst@utu.fi.
authors.forename: Maija
authors.initials: M
authors.lastname: Nyström
authors.affiliation: Laboratory of Industrial Physics, Department of Physics and Astronomy, University of Turku, Turku, Finland.
authors.forename: Jorma
authors.initials: J
authors.lastname: Roine
authors.affiliation: Laboratory of Industrial Physics, Department of Physics and Astronomy, University of Turku, Turku, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Murtomaa
authors.affiliation: Department of Chemical Engineering, Case Western Reserve University, Cleveland, OH, USA.
authors.forename: R
authors.initials: R
authors.lastname: Mohan Sankaran
authors.affiliation: Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland.
authors.forename: Hélder A
authors.initials: HA
authors.lastname: Santos
authors.affiliation: Laboratory of Industrial Physics, Department of Physics and Astronomy, University of Turku, Turku, Finland.
authors.forename: Jarno
authors.initials: J
authors.lastname: Salonen
mesh_terms: D002152:Calorimetry, Differential Scanning / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003460:Crystallization / Q000379:methods; D003461:Crystallography / Q000379:methods; D010894:Piroxicam / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods; D013696:Temperature; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D010894:Piroxicam
keywords: Crystallisation; Electrospraying; Electrostatic atomisation; Piroxicam; Polymorphism; XRD