title: Synthesis characterization and in vitro drug release from acrylamide and sodium alginate based superporous hydrogel devices.
abstract: OBJECTIVE
  Present investigation was aimed at developing gastroretentive superporous hydrogels (SPHs) having desired mechanical characteristics with sustained release.
  
  
  METHODS
  The acrylamide based SPHs of various generations (1(st), 2(nd) and 3(rd)) were synthesized by gas blowing technique. The prepared SPHs were evaluated for swelling, mechanical strength studies and scanning electron microscopy studies. Verapamil hydrochloride was loaded into selected SPHs by aqueous drug loading method and characterized via Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (X-RD), differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR) and in vitro drug release studies.
  
  
  RESULTS
  SPHs of third generation were observed to have desired mechanical strength with sufficient swelling properties. Integrity of the drug was maintained in hydrogel polymeric network as indicated by FTIR, X-RD, and DSC and NMR studies. Initially, fast drug release (up to 60%) was observed in 30 min in formulation batches containing pure drug only (A, C and E), which was further sustained untill 24 h.
  
  
  CONCLUSIONS
  The increase in mechanical strength was due to the chemical cross-linking of secondary polymer in hydrogel network. The initial burst release was due to the presence of free drug at the surface and later sustained drug release was due to diffusion of entrapped drug in polymeric network. Significant decrease in drug release was observed by the addition of hydroxypropyl methyl cellulose.
  
  
  CONCLUSIONS
  SPH interpenetrating networks with fast swelling and sufficient mechanical strength were prepared, which can be potentially exploited for designing gastroretentive drug delivery devices.
authors.affiliation: Department of Pharmaceutics, Chitkara College of Pharmacy, Chitkara University, Patiala, Punjab, India.
authors.forename: Manju
authors.initials: M
authors.lastname: Nagpal
authors.forename: Shailendra Kumar
authors.initials: SK
authors.lastname: Singh
authors.forename: Dinanath
authors.initials: D
authors.lastname: Mishra
keywords: Capillary channels; gastroretentive drug delivery; interpenetrating networks; mechanical strength; swelling properties