title: Preparation of ion-activated in situ gel systems of scopolamine hydrobromide and evaluation of its antimotion sickness efficacy.
abstract: OBJECTIVE
  To develop a novel, in situ gel system for nasal delivery of scopolamine hydrobromide (SCOP) and study its efficacy on motion sickness.
  
  
  METHODS
  SCOP in situ gels at 0.2%, 0.5%, and 1.0% gellan gum concentration (w/v) were prepared, respectively, and characterized in terms of viscosity, in vitro release, and nasal ciliotoxicity. Single photon emission computing tomography technique was used to evaluate the nasal residence time of gel containing (99m)Tc tracer. The antimotion sickness efficacy produced by the in situ gel formulation was investigated in rats and compared with those achieved after subcutaneous and oral administration.
  
  
  RESULTS
  The viscosity of the gellan gum formulations either in solution or in gel increased with increasing concentrations of gellan gum. Its release in vitro was moderate in artificial nasal fluid. The micrographic results showed that in situ gels were safe, without nasal ciliotoxicity. In comparison with phosphate buffer saline, a prolonged radioactivity of (99m)Tc in the rabbit nasal cavity was observed after administration of the gellan gum formulation. Intranasal SCOP in situ gel at a dose of 100 microg/kg decreased symptoms of motion sickness significantly in comparison with subcutaneous and oral administration (P<0.01).
  
  
  CONCLUSIONS
  SCOP nasal in situ gel is a safe and promising therapeutic alternative to existing medications for motion sickness.
authors: Department of Pharmaceutics, School of Pharmacy, Fudan University, Shanghai 200032, China.
authors: Shi-lei
authors: SL
authors: Cao
authors: Qi-zhi
authors: QZ
authors: Zhang
authors: Xin-guo
authors: XG
authors: Jiang
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D000932:Antiemetics / Q000008:administration & dosage* / Q000737:chemistry / Q000627:therapeutic use*; D002626:Chemistry, Pharmaceutical; D002923:Cilia / Q000187:drug effects; D005079:Excipients; D005782:Gels; D008297:Male; D009041:Motion Sickness / Q000188:drug therapy*; D009297:Nasal Mucosa / Q000378:metabolism; D011135:Polysaccharides, Bacterial; D051381:Rats; D017208:Rats, Wistar; D012601:Scopolamine / Q000008:administration & dosage* / Q000737:chemistry / Q000627:therapeutic use*; D014783:Viscosity
chemical_list: D000932:Antiemetics; D005079:Excipients; D005782:Gels; D011135:Polysaccharides, Bacterial; C048288:gellan gum; D012601:Scopolamine