title: A comparison of the effect of temperature and moisture on the solid dispersions: aging and crystallization.
abstract: The purpose of this work was to compare the effect of temperature and relative humidity (RH) on the physical stability and dissolution of solid dispersions. Cinnarizine-Soluplus(®) solid dispersions (SDs) at three different drug loadings (10, 20 and 35 wt%) were prepared by hot melt extrusion and exposed to stress conditions: high temperatures (40 and 60 °C), high relative humidities (75% and 94% RH) and accelerated conditions (40 °C/75% RH) for 30 days, or stored at 25 °C for up to 5 months. Changes in solid state and dissolution of SDs were investigated by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and dissolution testing. For samples under stress conditions, the results showed a reduced dissolution and a recrystallization of the drug with an increased crystallinity in the order of 40 °C/75% RH, >60 °C/0% RH, >25 °C/94% RH, >40 °C/0% RH, >25 °C/75% RH. For samples stored at 25 °C, nonlinear physical aging was observed and the dissolution also decreased although the SDs were still amorphous. The results indicated that temperature and humidity seemed to have comparable effects on the crystallization of cinnarizine-Soluplus(®) SDs. It is not reasonable to regard recrystallization as a sign of reduced dissolution, and glass transition temperature (Tg) may be a good indicator of the changes in dissolution.
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning, China. Electronic address: tianbin_1015@163.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Tian
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning, China. Electronic address: zhangling8786@163.com.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning, China. Electronic address: pange77@126.com.
authors.forename: Zhendong
authors.initials: Z
authors.lastname: Pan
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning, China. Electronic address: paladin.13@163.com.
authors.forename: Jingxin
authors.initials: J
authors.lastname: Gou
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning, China. Electronic address: zywinner01@163.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning, China. Electronic address: tanglab@126.com.
authors.forename: Xing
authors.initials: X
authors.lastname: Tang
mesh_terms: D002936:Cinnarizine / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D004355:Drug Stability; D006358:Hot Temperature; D006813:Humidity; D011092:Polyethylene Glycols / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D011208:Powders / Q000737:chemistry; D012995:Solubility; D044366:Transition Temperature; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D011145:Polyvinyls; D011208:Powders; C572167:polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer; D002936:Cinnarizine; D011092:Polyethylene Glycols
keywords: Aging; Crystallization; Dissolution; Moisture; Solid dispersion; Temperature