, Volume 10, Issue 2, pp 349–359 | Cite as

Quantification and Reduction of the Residual Chemical Reactivity of Passivated Biodegradable Porous Silicon for Drug Delivery Applications

  • Q. Shabir
  • K. Webb
  • D. K. Nadarassan
  • A. Loni
  • L. T. Canham
  • M. Terracciano
  • L. De Stefano
  • I. Rea
Open Access
Original Paper


The chemical reactivity of as-anodized porous silicon is shown to have an adverse effect on a model drug (Lansoprazole) loaded into the pores. The silicon hydride surfaces can cause unwanted reactions with actives during storage or use. Techniques such as thermal oxidation or surface derivitization can lower the reactivity somewhat, by replacing the reactive silicon-hydride species with a more benign oxide or functional group. However, by using a trio of analytical techniques (fluorometric dye assay, HPLC assay, and chemography) we show that residual hydride is still likely to be present and only after combining thermal oxidation with surface derivitization can the residual reactivity be reduced to those values typically observed with sol-gel (porous) silica. Potential sources of residual reactivity are discussed, with reference to data obtained by trace metal analysis, residual solvents, and pH measurements.


Porous silicon Reactivity Derivatization Drug delivery 


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© The Author(s) 2017

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  1. 1.pSiMedica Ltd, Malvern Hills Science ParkWorcesterUK
  2. 2.Institute for Microelectronics and MicrosystemsNational Research CouncilNaplesItaly
  3. 3.Department of PharmacyUniversity of Naples Federico IINaplesItaly

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