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  • A comparison of the effect of temperature and moisture on the solid dispersions: aging and crystallization.

A comparison of the effect of temperature and moisture on the solid dispersions: aging and crystallization.

International journal of pharmaceutics (2014-09-15)
Bin Tian, Ling Zhang, Zhendong Pan, Jingxin Gou, Yu Zhang, Xing Tang
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.

MATERIALS
Product Number
Brand
Product Description

Lysine hydrochloride, European Pharmacopoeia (EP) Reference Standard
Sigma-Aldrich
N,N′-Disuccinimidyl carbonate, purum, ≥95.0% (NMR)
Sigma-Aldrich
N,N′-Disuccinimidyl carbonate, ≥95%
Supelco
L-Lysine monohydrochloride, certified reference material, TraceCERT®, Manufactured by: Sigma-Aldrich Production GmbH, Switzerland
Supelco
L-Lysine monohydrochloride, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
L-Lysine monohydrochloride, BioUltra, ≥99.5% (AT)
Supelco
L-Lysine hydrochloride solution, 100 mM amino acid in 0.1 M HCl, analytical standard
Sigma-Aldrich
ε-Caprolactam, 99%
Sigma-Aldrich
L-Lysine monohydrochloride, reagent grade, ≥98% (HPLC)
Sigma-Aldrich
L-Lysine monohydrochloride, from non-animal source, meets EP, JP, USP testing specifications, suitable for cell culture, 98.5-101.0%
Supelco
ε-Caprolactam, analytical standard