IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
2D solid state homonuclear and heteronuclear correlation experiments to study a new pharmaceutical compound
Autor/es:
Y. GARRO LINCK; A.K CHATTAH; C. ROMAÑUK; M.E. OLIVERA; R.H. MANZO; S.L. CUFFINI; R. GRAF; G.A. MONTI; H.W. SPIESS
Lugar:
Göteborg, Suecia
Reunión:
Conferencia; EUROMAR Magnetic Resonance Conference; 2009
Resumen:
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Ciprofloxacin is a widely prescribed
broad-spectrum oral fluoroquinolone antibiotic. Low solubility and bitter taste are unfavorable properties associated
with most fluoroquinolones that limit their formulation. Saccharine
(SAC) derivatives, either as salts or co-crystals,
show an improved solubility behavior and better taste. [Romañuk et al. J.
Pharm. Sci. DOI: 10.1002/jps.2168]
Advanced
solid states nuclear magnetic resonance (NMR) techniques have been used to
study a new pharmaceutical compound, the ciprofloxacin saccharinate, CIP-SAC.
This compound has been previously reported and fully characterized with a
variety of solid state techniques (IR, DSC, XRD and 13C CP-MAS NMR).
This saccharinate evidences polymorphism presenting two well distinguished
solid forms, CIP-SAC (I) and (II).
In this
work we have performed 2D 13C-1H heteronuclear
correlation experiments (REPT-HSQC and HETCOR) which allowed the complete
assignment of the resolved 1H solid state spectrum. [Schnell et al. J.
Mag. Reson. 150, 5770 (2001) and van Rossum et al. J. Mag. Reson. 124,
516519 (1997)] These data
were complemented with double quantum MAS experiments (BABA pulse sequence [Schnell
et al. J. Mag. Reson. 133, 6169 (1998)]) to identify 1H-1H
connectivities, hydrogen bonds and dipolar proximities. The zwitterionic
character of ciprofloxacin and its derivative was identified. Further
information about inter and intra molecular interactions in both solid forms of
the new saccharinate was obtained. Differences and similarities in the
structures of the different solid forms have also been established and
supported with single crystal XR diffraction data obtained for CIP-SAC (II).