Netsu Sokutei, 31 (2), p. 74, (2004)

小特集-医薬品の安定性評価と熱測定

等温カロリメータによる非晶質製剤の構造緩和の評価

Investigation of the structural Relaxation Process of Amorphous Formulation by Isothermal Microcalorimetry

等温カロリメータを用いて非晶質材料の構造緩和および回復過程の評価を試みた。これまで汎用されてきたDSC法と異なり,本手法は緩和過程を直接観察することが可能である。また,ほとんど報告例のない回復過程も評価できることが分かった。両過程ともKWW式の導関数によって解析が可能であり,求められた緩和パラメータは,DSCより求められたものと一致することが確認された。本手法の長所と短所についても考察を行う。
The use of isothermal microcalorimetry for analyzing structural relaxation and recovery processes of amorphous materials is discussed. Unlike the conventional DSC method, this new method enables to directly monitor the relaxation process. Also featured in this article is its application for investigating the recovery process, which has hardly been reported in literature. The both processes were elucidated using Kohlrausch-Williams-Watts derivative, although its application for the recovery process needs discussion. The relaxation parameters obtained by this procedure agreed very well with those from the DSC method. The advantages and disadvantages of this method are summarized.