Multinuclear solid state NMR investigation of two polymorphic forms of Ciprofloxacin-saccharinate

Y. GARRO LINCK; A. K. CHATTAH; R. GRAF; C. B. ROMAÑUK; M. E. OLIVERA; R. H. MANZO; G. A. MONTI; H. W. SPIESS

PHYSICAL CHEMISTRY CHEMICAL PHYSICS

ROYAL SOC CHEMISTRY

Lugar: Cambridge; Año: 2011 vol. 13 p. 6590 - 6596

1463-9076

Two polymorphic forms of a novel pharmaceutical compound, ciprofloxacin-saccharinate (CIP-SAC), are analyzed using one dimensional (1D) and two dimensional (2D) 1 H nuclear magnetic resonance (NMR) at fast magic angle spinning (MAS). Additionally 15N spectroscopy and 1 H?13C correlation experiments were performed to complement our conclusions. The 1D 1 H NMR spectra of CIP and complexes reveal valuable information about the ionic bonding between ciprofloxacin and saccharine. Additionally, these spectra allow us to perform a clear characterization of each solid form, giving the number of molecules per unit cell in one of the polymorphs. From 2D 1 H?1 H spectra obtained through double quantum correlations we can arrive at important conclusions about the hydrogen bonding, conformation, and intra and inter-molecular interactions present in these compounds. Comparing and contrasting the 1 H?1 H correlation data obtained for both polymorphic forms and taking into account the single crystal structure data existing for the solid form CIP-SAC (II) was possible to extract some conclusions on the polymorph CIP-SAC (I) where no single crystal information is available. 1 H MAS NMR is shown to be an important tool in the field of polymorphism and for the characterization of multicomponent pharmaceutical compounds.