title: Swelling and aspirin release study: cross-linked pH-sensitive vinyl acetate-co-acrylic acid (VAC-co-AA) hydrogels.
abstract: The objective of this work was to develop new pH-sensitive hydrogels to deliver gastric mucosal irritating drugs to the lower part of the gastrointestinal tract. For this purpose, cross-linked vinyl acetate-co-acrylic acid (VAC-co-AA) hydrogels were synthesized by using N, N, methylene bisacrylamide (MBAAm) as a cross-linking agent. Different ratios of 90:10, 70:30, 50:50, 30:70, and 10:90 of VAC-co-AA were synthesized. All of the compositions were cross-linked using 0.15, 0.30, 0.45, and 0.60 mol percent MBAAm. Swelling and aspirin release were studied for 8 hour period. The drug release data were fitted into various kinetic models like the zero-order, first-order, Higuchi, and Peppas. Hydrogels were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. In addition to the above, these hydrogels were loaded with 2%, 8% and 14% w/v aspirin solutions, keeping the monomeric composition and degree of cross-linking constant. In conclusion, it can be said that aspirin can be successfully incorporated into cross-linked VAC/AA hydrogels and its swelling and drug release can be modulated by changing the mole fraction of the acid component in the gels.
authors.affiliation: Department of Pharmacy, Faculty of Pharmacy, Bahauddin Zakariya University, Multan, Pakistan. nazar_ranjha@hotmail.com
authors.forename: Nazar Mohammad
authors.initials: NM
authors.lastname: Ranjha
authors.forename: Jahanzeb
authors.initials: J
authors.lastname: Mudassir
mesh_terms: D000179:Acrylates / Q000737:chemistry*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry*; D001241:Aspirin / Q000737:chemistry*; D003432:Cross-Linking Reagents; D003460:Crystallization; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D020100:Hydrogels; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D011108:Polymers; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D014753:Vinyl Compounds / Q000737:chemistry*
chemical_list: D000179:Acrylates; D000894:Anti-Inflammatory Agents, Non-Steroidal; D003432:Cross-Linking Reagents; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D020100:Hydrogels; D011108:Polymers; D014753:Vinyl Compounds; C036658:acrylic acid; C011566:vinyl acetate; D001241:Aspirin