Ostwald-Freundlich diffusion-limited dissolution kinetics of nanoparticles

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• 作者：David R. Ely^aAuthor Vitae ; R. Edwin Garcí ; a^bAuthor Vitae ; Markus Thommes^a ; ^{markus.thommes@uni-duesseldorf.de" class="auth_mail}Author Vitae
• 关键词：Dissolution rate ; Thermodynamics ; Kinetics ; Mathematical model ; Surface energy ; Nanoparticles
• 刊名：Powder Technology
• 出版年：May, 2014
• 年：2014
• 卷：257
• 期：Complete
• 页码：120-123
• 全文大小：374 K

文摘

For many years, nanoparticles have garnered increasing interest in pharmaceutical investigations. It is well known that the solubility of nanoparticles increases with decreasing size due to the Gibbs-Thomson effect. However, there are currently no analytical models to describe the kinetics of nanoparticle dissolution. The purpose of this article is to provide a Thermodynamics-based description of the kinetics of nanoparticle dissolution. In particular, the Ostwald-Freundlich relation is used to correct dissolution times for small particles, which have higher solubilities than larger particles. The developed model is an extension of the Hixson-Crowell cube root law in which the total normalized dissolution time is corrected by a 鈥渟olubility size factor鈥?that approaches unity for increasing initial particle size. This model enables rapid estimation of the total dissolution time of spherical nanoparticles in a gently agitated, zero solute concentration reservoir. The total dissolution time predicted differs from Hixson-Crowell by nearly 10% for initial particle sizes fifty times larger than the characteristic particle size, and increases to more than a factor of six at the characteristic particle size. This work provides a physics-based description of the nanoparticle dissolution kinetics and details the reaches and limitations of the developed model. The theoretical framework provided herein is valid for a wide range of dissolution processes and size scales affording it a high level of practicality.