title: Prediction of recrystallization behavior of troglitazone/polyvinylpyrrolidone solid dispersion by solid-state NMR.
abstract: The purpose of this study was to elaborate the relationship between the (13)C CP/MAS NMR spectra and the recrystallization behavior during the storage of troglitazone solid dispersions. The solid dispersions were prepared by either the solvent method or by co-grinding. The recrystallization behavior under storage conditions at 40 degrees C/94% RH was evaluated by the Kolmogorov-Johnson-Mehl-Avrami (KJMA) equation. Solid dispersions prepared by the solvent method or by prolonged grinding brought about inhibition of the nucleation and the nuclei growth at the same time. No differences in the PXRD profiles were found in the samples prepared by the co-grinding and solvent methods, however, (13)C CP/MAS NMR showed significant differences in the spectra. The correlation coefficients using partial least square regression analysis between the PXRD profiles and the apparent nuclei-growth constant or induction period to nucleation were 0.1305 or 0.6350, respectively. In contrast, those between the (13)C CP/MAS NMR spectra and the constant or the period were 0.9916 or 0.9838, respectively. The (13)C CP/MAS NMR spectra had good correlation with the recrystallization kinetic parameters evaluated by the KJMA equation. Consequently, solid-state NMR was judged to be a useful tool for the prediction of the recrystallization behavior of solid dispersions.
authors.affiliation: Formulation Technology Research Laboratories, Daiichi Sankyo Co, Ltd, 1-2-58, Hiromachi, Tokyo 140-8710, Japan. ito.atsutoshi.y5@daiichisankyo.co.jp
authors.forename: Atsutoshi
authors.initials: A
authors.lastname: Ito
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Watanabe
authors.forename: Shuichi
authors.initials: S
authors.lastname: Yada
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hamaura
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nakagami
authors.forename: Kenjirou
authors.initials: K
authors.lastname: Higashi
authors.forename: Kunikazu
authors.initials: K
authors.lastname: Moribe
authors.forename: Keiji
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D002839:Chromans / Q000032:analysis / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011205:Povidone / Q000032:analysis / Q000737:chemistry*; D011237:Predictive Value of Tests; D045162:Thiazolidinediones / Q000032:analysis / Q000737:chemistry*; D000077288:Troglitazone; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D002839:Chromans; D045162:Thiazolidinediones; D011205:Povidone; D000077288:Troglitazone