title: Comparison of the properties of brand-name and generic nadifloxacin creams.
abstract: OBJECTIVE
  In external preparations, types and ratios of additives are not necessarily the same for brand-name drugs and generic drugs. Thus, the physicochemical properties of preparations may differ despite the fact that they contain the same ingredients or additives. This study examined differences in brand-name and generic versions of nadifloxacin (NFX) creams.
  
  
  METHODS
  Three types of NFX creams (NFX-A, NFX-B, and NFX-C) were used. The viscosity of each preparation was determined, its yield value was calculated, and each preparation was subjected to light microscopy, x-ray powder diffraction, and near-infrared absorption spectroscopy.
  
  
  RESULTS
  Comparison of viscosity of different preparations revealed that NFX-B had a lower viscosity than NFX-A and NFX-C (14.5 vs. 24.6 and 17.9 Pa·s). NFX-B also had a lower yield value than NFX-A and NFX-C. Microscopy revealed that NFX-A and NFX-B had satisfactory emulsification although crystallization was observed with NFX-C. Near-infrared absorption spectroscopy revealed changes in the absorption spectra of NFX-B in comparison with those of NFX-A and NFX-C that were due to differences in water content and differences in fat and oil content.
  
  
  CONCLUSIONS
  These findings confirmed that there were differences in the viscosity and flattening of NFX-A, NFX-B, and NFX-C. In addition, microscopy revealed differences in emulsification and it revealed the precipitation of NFX crystals in NFX-C. Near-infrared absorption spectroscopy revealed that differences in the type and amount of additives and water content in the creams had contributed to differences in the preparations.
authors.affiliation: Laboratory of Drug Safety Management, Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado-shi, Saitama, 3500295, Japan. yinoue@josai.ac.jp
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Inoue
authors.forename: Miruto
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kimura
authors.forename: Toru
authors.initials: T
authors.lastname: Tanaka
authors.forename: Ikuo
authors.initials: I
authors.lastname: Kanamoto
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D004304:Dosage Forms; D016568:Drugs, Generic / Q000737:chemistry; D005223:Fats / Q000032:analysis; D024841:Fluoroquinolones / Q000737:chemistry*; D008853:Microscopy; D009821:Oils / Q000032:analysis; D011807:Quinolizines / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared; D014783:Viscosity; D014867:Water / Q000032:analysis; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D004304:Dosage Forms; D016568:Drugs, Generic; D005223:Fats; D024841:Fluoroquinolones; D009821:Oils; D011807:Quinolizines; D014867:Water; C062127:nadifloxacin