On the role of API in determining porosity, pore structure and bulk modulus of the skeletal material in pharmaceutical tablets formed with MCC as sole excipient

Cathy Ridgway, Prince Bawuah, Daniel Markl, J. Axel Zeitler, Jarkko Ketolainen, Kai Erik Peiponen, Patrick Gane

Research output: Contribution to journalArticle

9 Citations (Scopus)
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Abstract

The physical properties and mechanical integrity of pharmaceutical tablets are of major importance when loading with active pharmaceutical ingredient(s) (API) in order to ensure ease of processing, control of dosage and stability during transportation and handling prior to patient consumption. The interaction between API and excipient, acting as functional extender and binder, however, is little understood in this context. The API indomethacin is combined in this study with microcrystalline cellulose (MCC) at increasing loading levels. Tablets from the defined API/MCC ratios are made under conditions of controlled porosity and tablet thickness, resulting from different compression conditions, and thus compaction levels. Mercury intrusion porosimetry is used to establish the accessible pore volume, pore size distribution and, adopting the observed region of elastic intrusion-extrusion at high pressure, an elastic bulk modulus of the skeletal material is recorded. Porosity values are compared to previously published values derived from terahertz (THz) refractive index data obtained from exactly the same tablet sample sets. It is shown that the elastic bulk modulus is dependent on API wt% loading under constant tablet preparation conditions delivering equal dimensions and porosity. The findings are considered of novel value in respect to establishing consistency of tablet production and optimisation of physical properties.

Original languageEnglish
Pages (from-to)321-331
Number of pages11
JournalInternational Journal of Pharmaceutics
Volume526
Issue number1-2
Early online date19 Apr 2017
DOIs
Publication statusPublished - 30 Jun 2017

Keywords

  • API impact on tablet structure
  • excipient-API interactions
  • mechanical properties of compacts
  • pharmaceutical tableting
  • tablet porosity

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