A structure parameter for porous pharmaceutical tablets obtained with the aid of Wiener bounds for effective permittivity and terahertz time-delay measurement

Research output: Contribution to journalArticle


  • Prince Bawuah
  • Mousumi Chakraborty
  • Tuomas Ervasti
  • J. Axel Zeitler
  • Jarkko Ketolainen
  • Patrick Gane

  • Kai-Erik Peiponen

Research units

  • University of Eastern Finland
  • University of Cambridge
  • Omya International AG


A structure parameter that can be used to predict the pattern of arrangement of porous inclusions in pharmaceutical tablets is introduced. By utilizing the effective refractive index of a pharmaceutical tablet obtained from terahertz time-domain measurements, we have shown that there exists a promising correlation between the calculated structural parameter and the porosity of training sets of pharmaceutical tablets, having well-defined characterization. Knowing of the structural arrangement, i.e. combined constituent skeletal-pore elements in series, parallel or mixed within porous media, could serve as a basis for understanding the ingress and permeation of liquids in such media. In the realm of pharmaceutical applications, such knowledge of the structural arrangement of air voids within a medicinal tablet could enable correlation with mechanical strength and dissolution behaviour in aqueous systems.


Original languageEnglish
Pages (from-to)87-92
Number of pages6
JournalInternational Journal of Pharmaceutics
Issue number1-2
Publication statusPublished - 2016
MoE publication typeA1 Journal article-refereed

    Research areas

  • Effective medium, Indomethacin, Microcrystalline cellulose, Microstructures, Pharmaceutical tablet, Terahertz

ID: 3251320