Solid State Interconversion Between Anhydrous Norfloxacin and Its Hydrates

Chongcharoen, Wanchai; Byrn, Stephen R.; Sutanthavibul, Narueporn

doi:10.1002/jps.21165

Cited by 32 publications

(30 citation statements)

References 25 publications

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“…Hence, the solid form NOR B I obtained is not a mixture of forms C and B, as supported by 13 C CP‐MAS. Additionally, the PXRD data of NOR B I show reflections at 2 θ = 10.7°, 11.4°, 12.6°, and 13.4°, which are in agreement with previous hydrates reported in for NOR A . Then, in order to complete the characterization of this solid, we performed a thermogravimetric analysis (TGA) experiment (Figure 1S in Supporting Information).…”

Section: Resultssupporting

confidence: 84%

“…11 However, the PXRD pattern for NOR B I displays reflections distinctly different from those reported previously for NOR B. 30 Then, in order to complete the characterization of this solid, we performed a thermogravimetric analysis (TGA) experiment ( Figure 1S in Supporting Information). Our TGA results together with PXRD reveal that the new solid form obtained corresponds to a hydrate of the polymorph B, which is reported for the first time herein.…”

Section: Powder X-ray Diffractionmentioning

confidence: 94%

See 1 more Smart Citation

Insights into Novel Supramolecular Complexes of Two Solid Forms of Norfloxacin and β-Cyclodextrin

Chattah

Mroué

Pfund

et al. 2013

Journal of Pharmaceutical Sciences

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The solid-state properties of novel complexes of β-cyclodextrin and two different solid forms of norfloxacin were investigated at the molecular level, in an attempt to obtain promising candidates for the preparation of alternative matrices used in pharmaceutical oral formulations. In order to evaluate the physical properties inherited from the different polymorphs, these supramolecular systems were characterized using a variety of spectroscopic techniques including natural-abundance (13) C cross-polarization magic-angle-spinning (CP-MAS) nuclear magnetic resonance (NMR), powder X-ray diffraction, and Fourier transform infrared spectroscopy. The intrinsic proton spin-lattice relaxation times detected in (13) C CP-MAS NMR spectra are used to confirm and distinguish the complex formation, as well as to provide better insights into the molecular fragments that are involved in the interaction with β-cyclodextrin.

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Section: Resultssupporting

confidence: 84%

Section: Powder X-ray Diffractionmentioning

confidence: 94%

Insights into Novel Supramolecular Complexes of Two Solid Forms of Norfloxacin and β-Cyclodextrin

Chattah

Mroué

Pfund

et al. 2013

Journal of Pharmaceutical Sciences

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show abstract

“…The p K a of the COOH group in the fluoroquinolone drug (∼6) is at least two orders less acidic than the organic acids used (<4), and hence zwitterionic form of the drug was not expected. Another reason for studying norfloxacin salts was that this drug exists in many hydrates of continuously varying stoichiometry23,24 from 1.0 to 5.0 water molecules in the crystal lattice, and this can cause variable activity in drug action.…”

Section: Resultsmentioning

confidence: 99%

Fluoroquinolone salts with carboxylic acids

Reddy

Ganesh

Nagalapalli

et al. 2011

Journal of Pharmaceutical Sciences

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“…However, it is not possible to establish simple relationships between the stoichiometry of water coordination in hydrates and the rate and/or humidity onset of hydrate formation. Previous reports have shown that the transformation rate is also a function of compound‐specific properties, hydrogen‐bonding patterns, and surface properties, and that interconversion pathways and stoichiometry of hydrates can be affected by a combination of moisture levels, temperatures, and duration of exposure …”

Section: Resultsmentioning

confidence: 99%