title: Synthesis of chemically cross-linked polyvinyl alcohol-co-poly (methacrylic acid) hydrogels by copolymerization; a potential graft-polymeric carrier for oral delivery of 5-fluorouracil.
abstract: BACKGROUND
  The propose of the present work was to develop chemically cross-linked polyvinyl alcohol-co-poly(methacrylic acid) hydrogel (PVA-MAA hydrogel) for pH responsive delivery of 5-Fluorouracil (5-FU).
  
  
  METHODS
  PVA based hydrogels were prepared by free radical copolymerization. PVA has been cross-linked chemically with monomer (methacrylic acid) in aqueous medium, cross-linking agent was ethylene glycol di-methacrylate (EGDMA) and benzoyl peroxide was added as reaction initiator. 5-FU was loaded as model drug. FTIR, XRD, TGA and DSC were performed for characterization of copolymer. Surface morphology was studied by SEM. pH sensitive properties were evaluated by swelling dynamics and equilibrium swelling ratio at low and higher pH.
  
  
  RESULTS
  FTIR, XRD, TGA and DSC studies confirmed the formation of new copolymer. Formulations with higher MAA contents showed maximum swelling at 7.4 pH. High drug loading and higher drug release has been observed at pH 7.4.
  
  
  CONCLUSIONS
  The current study concludes that a stable copolymeric network of PVA was developed with MAA. The prepared hydrogels were highly pH responsive. This polymeric network could be a potential delivery system for colon targeting of 5-FU in colorectal cancers.
authors.affiliation: Faculty of Pharmacy and Alternative Medicine, the Islamia University of Bahawalpur-63100, Punjab, Pakistan. ma786_786@yahoo.com.
authors.forename: Muhammad Usman
authors.initials: MU
authors.lastname: Minhas
authors.forename: Mahmood
authors.initials: M
authors.lastname: Ahmad
authors.forename: Liaqat
authors.initials: L
authors.lastname: Ali
authors.forename: Muhammad
authors.initials: M
authors.lastname: Sohail