Studies on crystal forms of lomefloxacin hydrochloride: preparation, characterization and dissolution profile

Abstract

Crystal habit modification of lomefloxacin hydrochloride was obtained by recrystallization from various solvents based on polarity. Among the various solvents, water, methanol and ethanol can produce well defined crystal forms. The newly obtained crystals were characterized by analytical techniques viz. Optical microscopy, FT-IR spectroscopy, X-ray diffraction, Differential scanning calorimetry. In addition, the crystals were evaluated for melting point, solubility and dissolution profile. The newly developed crystals possess the different physicomechanical properties but chemically identical. The crystals obtained from water are rod shaped whereas the crystals obtained from methanol and ethanol are thin needle shape. The FT-IR spectra of newly developed crystals showed the characteristic peak as that of commercial sample. In addition, DSC spectra of newly developed crystals showed significant change in the melting endothermic compare to commercial sample and the XRD spectra revealed the slight difference in the diffraction pattern compare to commercial sample. The obtained crystals have different melting point. The crystal obtained from methanol and ethanol markedly improved solubility and dissolution profile compared to crystal obtained from water and commercial sample. Thus, the DSC and XRD indicate existence of different crystal forms of lomefloxacin.