title: Effect of HPMC concentration on β-cyclodextrin solubilization of norfloxacin.
abstract: The effect of hydroxypropyl methylcellulose (HPMC) concentration on β-cyclodextrin (β-CD) solubilization of norfloxacin was examined. The solubility and dissolution of norfloxacin/β-CD and norfloxacin/β-CD/HPMC inclusion complexes were studied. The presence of β-CD increased significantly the solubility and dissolution of norfloxacin. The addition of HPMC until 5% (w/w) improved the solubilization of norfloxacin but further addition above 5% (w/w), decreased norfloxacin solubilization. Fourier transformed Infra-red (FTIR) showed that norfloxacin was successfully included into β-CD. Differential scanning calorimetry (DSC) showed that the norfloxacin endothermic peak shifted to a lower temperature with reduced intensity indicating the formation of inclusion complex. The addition of HPMC reduced further the intensity of norfloxacin endothermic peak. Most of the sharp and intense peaks of norfloxacin disappeared with the addition of HPMC. In conclusion, the concentration of hydrophilic polymer used to enhance β-CD solubilization of poorly soluble drugs is very critical.
authors.affiliation: School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.
authors.forename: Gabriel Onn Kit
authors.initials: GO
authors.lastname: Loh
authors.forename: Yvonne Tze Fung
authors.initials: YT
authors.lastname: Tan
authors.forename: Kok Khiang
authors.initials: KK
authors.lastname: Peh
mesh_terms: D065347:Hypromellose Derivatives; D008747:Methylcellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D009643:Norfloxacin / Q000737:chemistry*; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D014835:Volatilization; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D012997:Solvents; D047392:beta-Cyclodextrins; D065347:Hypromellose Derivatives; D008747:Methylcellulose; C031215:betadex; D009643:Norfloxacin
keywords: Differential scanning calorimetry; Fourier transformed infra-red; Norfloxacin/β-CD; Norfloxacin/β-cyclodextrin/HPMC; X-ray powder diffraction