Formulation of an anti-inflammatory drug using pH responsive poly(methacrylic acid)(PMAA)-graft-hollow silica for oral drug delivery

• Main Author: Kong, Wai Tuck.
• Other Authors: Hu Xiao
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Materials::Biomaterials
• Online Access: http://hdl.handle.net/10356/35521
• Institution: Nanyang Technological University

pH responsive properties of poly(methacrylic acid) (PMAA) grafted nano-sized hollow silica (PMAA-g-HSi) were characterized, and better formulation of sulfasalazine (an anti-inflammatory pro-drug used for bowel disease) was pursued using PMAA-g-HSi. To investigate pH responsive behaviour of PMAA-g-HSi, fluorescein-isothiocyanate-dextran (FITC-dextran), was used a probe and the release profile of FITC-dextran was monitored using fluorescence spectrometer. It was found that FITC-dextran loaded into PMAA-g-HSi was retained in the PMAA-g- HSi under acidic condition (pH2) for as long as 24h. However, FITC-dextran was released in a single burst release when pH was increased to above 7. In order to get better formulation of sulfasalazine with target delivery site at intestine (pH > 7) and without drug loss and degradation at acidic stomach (pH <3), pH responsive PMAAg- HSi was applied for encapsulation of sulfasalazine. Factors including drug concentration, ultra-sonication time, and drug recycling, on the drug loading capacity were investigated using UV spectroscopy. Also pH dependent release profile of sulfasalazine from PMAA-g-HSi was monitored using UV spectroscopy. It was shown that sulfasalazine was kept in PMAA-g-HSi at pH <2 but was released out at pH > 7. So PMAA-g-HSi is promising for better formulation of sulfasalazine.