colon-specific drug delivery behavior of ph-responsive pmaaperlite composite结肠靶向给药的行为ph-responsive pmaaperlite复合.pdf

Int. J. Mol. Sci. 2010, 11, 1546-1556; doi:10.3390/ijm   OPEN ACCESS International Journal of Molecular Sciences ISSN 1422-0067 /journal/ijms Article Colon-Specific Drug Delivery Behavior of pH-Responsive PMAA/Perlite Composite Mehrdad Mahkam * and Laleh Vakhshouri Chemistry Department, Azarbaijan University of Tarbiat Moallem, Tabriz, Iran * Author to whom correspondence should be addressed; E-Mail: mmahkam@ or mahkam@; Tel.: +98 412 432 7541. Received: 12 March 2009 / Accepted: 12 April 2010 / Published: 12 April 2010 Abstract: The preparation, characterization, and in vitro release of 5-aminosalicylic acid (5-ASA) from methacrylic acid (MAA)/perlite composites (APC) prepared via a sol–gel route are reported. The free-radical graft polymerization of methacrylic acid (MAA) onto perlite particles was studied experimentally. The grafting procedure consisted of surface activation with 3-(trimethoxysilyl) propyl methacrylate (TSPA), followed by free-radical graft polymerization of methacrylic acid (MAA) in ethyl acetate with 2,2΄-azobis- isobutyronitrile (AIBN) initiator. The composition of the composites hybrid materials was determined by FTIR spectroscopy. Equilibrium swelling studies were carried out in enzyme-free simulated gastric and intestinal fluids (SGF and SIF, respectively). The dried composites were immersed