Related Experiment Video
Updated: May 17, 2026

A Package of Established Analytical Tools to Investigate the Solid-State Alteration of Lipid-Based Excipients
Published on: August 9, 2022
Evaluation of crystallization behavior on the surface of nifedipine solid dispersion powder using inverse gas
Hideo Miyanishi1, Takayuki Nemoto, Masayasu Mizuno
1Pharmaceutical Research and Technology Laboratories, Astellas Pharma Inc., 180 Ozumi, Yaizu, Shizuoka, 425-0072, Japan. hideo.miyanishi@astellas.com
Purpose:
To investigate crystallization behavior on the surface of amorphous solid dispersion powder using inverse gas chromatography (IGC) and to predict the physical stability at temperatures below the glass transition temperature (T (g)).
Methods:
Amorphous solid dispersion powder was prepared by melt-quenching of a mixture of crystalline nifedipine and polyvinylpyrrolidon (PVP) K-30. IGC was conducted by injecting undecane (probe gas) and methane (reference gas) repeatedly to the solid dispersion at temperatures below T (g). Surface crystallization was evaluated by the retention volume change of undecane based on the observation that the surface of the solid dispersion with crystallized nifedipine gives an increased retention volume.
Results:
On applying the retention volume change to the Hancock-Sharp equation, surface crystallization was found to follow a two-dimensional growth of nuclei mechanism. Estimation of the crystallization rates at temperatures far below T (g) using the Avrami-Erofeev equation and Arrhenius equation showed that, to maintain its quality for at least three years, the solid dispersion should be stored at -20°C (T (g) - 65°C).
Conclusions:
IGC can be used to evaluate crystallization behavior on the surface of a solid dispersion powder, and, unlike traditional techniques, can also predict the stability of the solid dispersion based on the surface crystallization behavior.
More Related Videos
10:10Transport Properties of Ibuprofen Encapsulated in Cyclodextrin Nanosponge Hydrogels: A Proton HR-MAS NMR Spectroscopy Study
Published on: August 15, 2016
09:24Application and Methodology of the Non-destructive 19F Time-domain NMR Technique to Measure the Content in Fluorine-containing Drug Products
Published on: August 22, 2017
Related Concept Videos
In Vitro Drug Dissolution: Alternative Methods
Factors Affecting Dissolution: Particle Size and Effective Surface Area
Drug Dissolution: Requirements and Profile Comparison
Factors Influencing Drug Absorption: Pharmaceutical Parameters
In Vitro Drug Dissolution: Compendial Testing Models II
In Vitro Drug Dissolution: Compendial Testing Models I