title: Investigation of inclusion complex of cilnidipine with hydroxypropyl-β-cyclodextrin.
abstract: The objective of this study was to improve the water-solubility and photostability of cilnidipine by complexing it with hydroxypropyl-β-cyclodextrin (HP-β-CD or HP-beta-CD). The interactions of cilnidipine and HP-β-CD were characterized by ultra violet-visible (UV/VIS) spectroscopy, differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Fourier transformation-infrared (FT-IR) spectroscopy and (1)H nuclear magnetic resonance ((1)H NMR) spectroscopy to verify the formation of cilnidipine-HP-β-CD complex inclusion. Moreover, the binding sites in the HP-β-CD structure were also tracked through (1)H NMR spectroscopy analysis. All the characterization information proved the formation of cilnidipine-HP-β-CD inclusion complex, and the results demonstrated the superiority of the inclusion complex in dissolution rates and photostability; in addition, the apparent solubility of cilnidipine was increased more than 10,000-fold in the presence of HP-β-CD. The stability constant (1:1) was found to be 50,116 M(-1), suggesting a high tendency of the drug to enter the HP-β-CD cavity. These results identified the cilnidipine-HP-β-CD inclusion complex as an effective new approach to design a novel formulation for pharmaceutical application.
authors.affiliation: School of Pharmaceutical Sciences, Hebei University, Baoding, China. hbupharm@126.com
authors.forename: Liandong
authors.initials: L
authors.lastname: Hu
authors.forename: Hailei
authors.initials: H
authors.lastname: Zhang
authors.forename: Weihua
authors.initials: W
authors.lastname: Song
authors.forename: Deliang
authors.initials: D
authors.lastname: Gu
authors.forename: Qiaofeng
authors.initials: Q
authors.lastname: Hu
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D002152:Calorimetry, Differential Scanning; D004095:Dihydropyridines / Q000737:chemistry / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D010777:Photochemistry; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction; D047392:beta-Cyclodextrins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D004095:Dihydropyridines; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin; C065927:cilnidipine