title: Bilayered films based on novel polymer derivative for improved ocular therapy of gatifloxacin.
abstract: BACKGROUND
  Thiomers could prove to be suitable mucoadhesives for fabrication of ocular inserts.
  
  
  OBJECTIVE
  The study intends to explore the application of thiolated sodium alginate (TSA) to the preparation of bilayered ocular inserts of gatifloxacin.
  
  
  METHODS
  Cysteine moieties were grafted onto sodium alginate (SA) and the resultant thiomer was characterized for relevant physicochemical properties. Bilayered inserts were fabricated with a mucoadhesive immediate release layer composed of either SA or TSA and a sustained release layer composed of acrylates. Films were prepared by solvent evaporation and evaluated for mechanical properties, drug content, and in vitro release.
  
  
  CONCLUSIONS
  The synthesized TSA possessed 248.80 ± 49.7 μ mol thiol groups/gm and its solutions thickened on standing due to disulphide bridging. Its films showed improved mucoadhesion and also a strikingly beneficial property of resisting erosion and remaining as a hydrated adhesive layer for the duration of drug release. The bilayered films were found to be flexible, with good folding endurance, uniform thickness, and appropriate drug content, and showed a release of about 80% of loaded gatifloxacin in 12 h.
  
  
  CONCLUSIONS
  The study demonstrates promise in employing thiolated polymer in conjunction with acrylates for the design of ocular inserts for twice a day therapy with gatifloxacin.
authors: Department of Pharmaceutics, Bombay College of Pharmacy, Kalina, Santacruz East, Mumbai 400 098, India.
authors: Naval Dinesh
authors: ND
authors: Aher
authors: Department of Pharmaceutics, Bombay College of Pharmacy, Kalina, Santacruz East, Mumbai 400 098, India.
authors: Hema Ajit
authors: HA
authors: Nair
mesh_terms: D000464:Alginates / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D003545:Cysteine / Q000737:chemistry; D016503:Drug Delivery Systems; D024841:Fluoroquinolones / Q000008:administration & dosage* / Q000737:chemistry*; D000077734:Gatifloxacin; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D012212:Rheology; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000464:Alginates; D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D006603:Hexuronic Acids; D011108:Polymers; D020723:Glucuronic Acid; D003545:Cysteine; D000077734:Gatifloxacin