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Journal of Nanomaterials
Volume 2013, Article ID 503069, 7 pages
Research Article

Effects of Polymeric Additives on the Crystallization and Release Behavior of Amorphous Ibuprofen

1Department of Chemical Engineering, Soongsil University, Seoul 156-743, Republic of Korea
2School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, Republic of Korea

Received 28 April 2013; Accepted 30 June 2013

Academic Editor: Krasimir Vasilev

Copyright © 2013 Su Yang Lee et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Some polymeric additives were studied to understand their effects on the amorphous phase of ibuprofen (IBU), used as a poorly water soluble pharmaceutical model compound. The amorphous IBU in bulk, as well as in nanopores (diameter ~24 nm) of anodic aluminum oxide, was examined with the addition of poly(acrylic acid), poly(N-vinyl pyrrolidone), or poly(4-vinylphenol). Results of bulk crystallization showed that they were effective in limiting the crystal growth, while the nucleation of the crystalline phase in contact with water was nearly instantaneous in all cases. Poly(N-vinyl pyrrolidone), the most effective additive, was in specific interaction with IBU, as revealed by IR spectroscopy. The addition of the polymers was combined with the nanoscopic confinement to further stabilize the amorphous phase. Still, the IBU with addition of polymeric additives showed sustained release behavior. The current study suggested that the inhibition of the crystal nucleation was probably the most important factor to stabilize the amorphous phase and fully harness its high solubility.