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Controlled Release of 5-Aminosalicylic Acid (5-ASA) from New Biodegradable Polyurethanes
Petrochemical Research Chair, Chemistry Department, College of Science, King Saud University, P.O. Box: 2455 Riyadh 11451, Saudi Arabia
Polymer Research Group, Chemistry Department, Faculty of Science, Tanta University, Tanta 31527, Egypt
* Authors to whom correspondence should be addressed.
Received: 23 February 2010; in revised form: 11 March 2010 / Accepted: 22 March 2010 / Published: 30 March 2010
Abstract: Segmented polyurethanes containing azo aromatic groups in the main chain were synthesized by reaction of 3,3'-azobis(6-hydroxybenzoic acid) (ABHB), 5-[4-(hydroxyphenyl)azo] salicylic acid (HPAS), and 5-[1-hydroxynaphthyl)azo] salicylic acid (HNAS) with hexamethylenediisocyanate (HDI). All synthesized monomers and polymers were characterized by elemental analysis, FTIR, 1H-NMR spectra, TGA and DSC analysis. All the synthesized azo polymers showed good thermal stability and the onset decomposition temperature of all these polymers was found to be above 195 ºC under nitrogen atmosphere.The release of 5-ASA under physiological conditions (pH = 7.8 and pH = 1.5) was investigated at body temperature (37 ºC). The release rate of 5-ASA increased with increasing pH (i.e., 7.8 > 1.5).
Keywords: 5-aminosalicylic acid; azo polymers; biodegradable polymers; polyurethane; drug delivery systems
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Kenawy, E.-R.; Al-Deyab, S.S.; El-Newehy, M.H. Controlled Release of 5-Aminosalicylic Acid (5-ASA) from New Biodegradable Polyurethanes. Molecules 2010, 15, 2257-2268.
Kenawy E-R, Al-Deyab SS, El-Newehy MH. Controlled Release of 5-Aminosalicylic Acid (5-ASA) from New Biodegradable Polyurethanes. Molecules. 2010; 15(4):2257-2268.
Kenawy, El-Refaie; Al-Deyab, Salem S.; El-Newehy, Mohamed H. 2010. "Controlled Release of 5-Aminosalicylic Acid (5-ASA) from New Biodegradable Polyurethanes." Molecules 15, no. 4: 2257-2268.