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AAPS PharmSciTech. 2003 December; 4(4): 406–412.
Published online 2003 September 16. doi:  10.1208/pt040451
PMCID: PMC2750644

Superporous IPN hydrogels having enhanced mechanical properties


The objective of this study was to improve the mechanical properties of superporous hydrogels (SPHs), which were used to develop gastric retention devices for long-term oral drug delivery. The main approach used in this study was to form an interpenetrating polymer network by incorporating a second polymer network inside an SPH structure. Polyacrylonitrile was used as the second network inside an SPH. Mechanical properties including compression strength and elasticity were significantly improved, up to 50 times as compared with the control SPHs. The enhanced mechanical properties were a result of the scaffold-like fiber network structures formed inside the cell walls of SPHs. The fast swelling property of SPHs was not affected by the incorporation of the second polymer network because the interconnected pore structures were maintained. Gastric retention devices based on superporous IPN hydrogels (SPIHs) with the improved mechanical properties are expected to withstand compression pressure and mechanical frictions in the stomach better than the control SPHs.

Keywords: superporous hydrogels, interpenetrating polymer networks, polyacrylonitrile, gastric retention devices, elasticity

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.
1. Chen J, Park H, Park K. Superporous hydrogels: fast responsive hydrogel systems. Proc ACS Div Polym Mat Sci Eng. 1998;79:236–237.
2. Chen J, Blevins WE, Park H, Park K. Gastric retention properties of superporous hydrogel composites. J Control Release. 2000;64(1–4):39–51. doi: 10.1016/S0168-3659(99)00139-X. [PubMed] [Cross Ref]
3. Agyilirah GA, Green M, DuCret R, Banker GS. Evaluation of the gastric retention properties of a cross-linked polymer coated tablet versus those of a non-disintegrating tablet. Int J Pharm. 1991;75:241–247. doi: 10.1016/0378-5173(91)90198-W. [Cross Ref]
4. Ichikawa M, Watanabe S, Miyake Y. A new multiple-unit oral floating dosage system. I: preparation and in vitro evaluation of floating and sustained-release characteristics. J Pharm Sci. 1991;80:1062–1066. doi: 10.1002/jps.2600801113. [PubMed] [Cross Ref]
5. Ichikawa M., Kato T, Kawahara M, Watanabe S, Kayano M. A new multiple-unit oral floating dosage system. II: in vivo evaluation of floating and sustained-release characteristics with p-aminobenzoic acid and isosorbide dinitrate as model drugs. J Pharm Sci. 1991;80:1153–1156. doi: 10.1002/jps.2600801212. [PubMed] [Cross Ref]
6. Hilton AK, Deasy PB. In vitro and in vivo evaluation of an oral sustained-release floating dosage form of amoxicillin trihydrate. Int J Pharm. 1992;86:79–88. doi: 10.1016/0378-5173(92)90033-X. [Cross Ref]
7. Chen J, Park K. Synthesis and characterization of superporous hydrogels composites. J Control Release. 2000;65(1–2):73–82. doi: 10.1016/S0168-3659(99)00238-2. [PubMed] [Cross Ref]
8. Chen J, Park H, Park K. Synthesis of superporous hydrogels: hydrogels with fast swelling and superabsorbent properties. J Biomed Mater Res. 1999;44:53–62. doi: 10.1002/(SICI)1097-4636(199901)44:1<53::AID-JBM6>3.0.CO;2-W. [PubMed] [Cross Ref]
9. Park K, Chen J. Superporous hydrogel composites: a new generation of hydrogels with fast swelling kinetics, high swelling ratio and high mechanical strength. In: Ottenbrite RM, Kim SW, editors. Polymeric Drugs & Drug Delivery Systems. Lancaster, PA: Technomic Publishing Company; 2001. pp. 145–155.
10. Wu M. Acrylonitrile and acrylonitrile polymers. In: Mark HF, editor. Encyclopedia of Polymer Science and Technology. 3rd ed. Hoboken, NJ: Wiley-Interscience; 2003. pp. 124–174.

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