title: DSC, X-ray and FTIR studies of a gemfibrozil/dimethyl-β-cyclodextrin inclusion complex produced by co-grinding.
abstract: The steps of formation of an inclusion complex produced by the co-grinding of gemfibrozil and dimethyl-β-cyclodextrin were investigated by differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD) and Fourier transform infrared (FTIR) spectroscopy with curve-fitting analysis. The endothermic peak at 59.25°C reflecting the melting of gemfibrozil progressively disappeared from the DSC curves of the products on increase of the duration of co-grinding. The crystallinity of the samples too gradually decreased, and after 35min of co-grinding the product was totally amorphous. Up to this co-grinding time, XRPD and FTIR investigations indicated a linear correlation between the cyclodextrin complexation and the co-grinding time. After co-grinding for 30min, the ratio of complex formation did not increase. These studies demonstrated that co-grinding is a suitable method for the complexation of gemfibrozil with dimethyl-β-cyclodextrin. XRPD analysis revealed the amorphous state of the gemfibrozil-dimethyl-β-cyclodextrin product. FTIR spectroscopy with curve-fitting analysis may be useful as a semiquantitative analytical method for discriminating the molecular and amorphous states of gemfibrozil.
authors.affiliation: Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Szeged, H-6720 Szeged, Eötvös u. 6, Hungary. aigner@pharm.u-szeged.hu
authors.forename: Z
authors.initials: Z
authors.lastname: Aigner
authors.forename: O
authors.initials: O
authors.lastname: Berkesi
authors.forename: G
authors.initials: G
authors.lastname: Farkas
authors.forename: P
authors.initials: P
authors.lastname: Szabó-Révész
mesh_terms: D002152:Calorimetry, Differential Scanning / Q000379:methods*; D015248:Gemfibrozil / Q000737:chemistry*; D000960:Hypolipidemic Agents / Q000737:chemistry*; D033362:Powder Diffraction / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D000960:Hypolipidemic Agents; D047392:beta-Cyclodextrins; C038119:heptakis(2,6-O-dimethyl)beta-cyclodextrin; D015248:Gemfibrozil