A Device to Crystallize Organic Solids: Structure of Ciprofloxacin, Midazolam, and Ofloxacin as Targets

Abstract

The crystal structure determination of the anhydrous form of any organic compound has been a challenge because of solvent incorporation during crystallization. A device to grow anhydrous forms of low melting organic solids based on vaporization and condensation by a gradient cooling technique has been designed. Its utility has been evaluated by growing anhydrous forms of ciprofloxacin, midazolam, and ofloxacin. Ciprofloxacin crystallizes in triclinic P1, midazolam in monoclinic P2 1 /n, and ofloxacin in the C2/c space group. Comparative studies on the conformational features with solvated structure show no significant variation in the aromatic moieties.

Crystal Structure of Levofloxacin Anhydrates: A High-Temperature Powder X-ray Diffraction Study Versus Crystal Structure Prediction

“…4,5 The crystal structure of the chiral ofloxacin is also known. 12,13 However, it is important to emphasize that levofloxacin is the pure (S)-(−)-enantiomer of the drug ofloxacin, which is marketed as another quinolone agent in an equimolar mixture of enantiomers. This large number of crystal forms of levofloxacin is relevant, since from a pharmaceutical perspective they can also be the subject of commercialization and patent protection if they follow the patentability requirements: novelty, inventive step, and industrial applicability.…”

Crystal Structure Prediction in the Context of Pharmaceutical Polymorph Screening and Putative Polymorphs of Ciprofloxacin

“…The heteroassociation between ciprofloxacin and norfloxacin leading to cocrystal synthesis was also reported [63]. A single crystal structure report of ciprofloxacin was also available in the literature [64]. The hydrogel [65], nanostructured delivery [66] systems and microparticles [67] for cp have also been reported in recent past.…”

Intermolecular interactions, disorder and twinning in ciprofloxacin–2,2-difluoroethanol (2/3) and ciprofloxacin–water (3/14.5)

“…A search of the Cambridge Structural Database (Version 5.31 with updates to May 2010; Allen, 2002) reveals 68 crystal structures containing the Cf molecule. These include the structures of the anhydrous form (Fabbiani et al, 2009;Mahapatra et al, 2010), a hexahydrate (Turel et al, 1997;Fabbiani & Dittrich, 2008), hydrated sodium salts crystallized under high-pressure conditions and recoverable to ambient pressure (Fabbiani et al, 2009), a lactate sesquihydrate (Prasanna & Guru Row, 2001), a hemi-methanolate (Li et al, 2006), a hydrochloride 1.34-hydrate (Turel & Golobič, 2003), and several coordination complexes with group II or lanthanide elements.…”