title: Optimization and characterization of gastroretentive floating drug delivery system using Box-Behnken design.
abstract: BACKGROUND
  One among many strategies to prolong gastric residence time and improve local effect of the metronidazole in stomach to eradicate Helicobacter pylori in the treatment of peptic ulcer was floating drug delivery system particularly effervescent gastroretentive tablets.
  
  
  OBJECTIVE
  The objective of this study was to prepare and evaluate, effervescent floating drug delivery system of a model drug, metronidazole.
  
  
  METHODS
  Effervescent floating drug delivery tablets were prepared by wet granulation method. A three-factor, three levels Box-Behnken design was adopted for the optimization. The selected independent variables were amount of hydroxypropyl methylcellulose K 15M (X1), sodium carboxy methylcellulose (X2) and NaHCO3 (X3). The dependent variables were floating lag time (YFLT), cumulative percentage of metronidazole released at 6th h (Y6) and cumulative percentage of metronidazole released at 12th h (Y12). Physical properties, drug content, in vitro floating lag time, total floating time and drug release behavior were assessed.
  
  
  RESULTS
  YFLT range was found to be from 1.02 to 12.07 min. The ranges of other responses, Y6 and Y12 were 25.72 ± 2.85 to 77.14 ± 3.42 % and 65.47 ± 1.25 to 99.65 ± 2.28 %, respectively. Stability studies revealed that no significant change in in vitro floating lag time, total floating time and drug release behavior before and after storage.
  
  
  CONCLUSIONS
  It can be concluded that a combination of hydroxypropyl methylcellulose K 15M, sodium carboxy methylcellulose and NaHCO3 can be used to increase the gastric residence time of the dosage form to improve local effect of metronidazole.
authors: National Facilities in Engineering and Technology with Industrial Collaboration (NAFETIC) centre, University College of Pharmaceutical Sciences, Kakatiya University , Warangal, AP , India.
authors: Kishore
authors: K
authors: Rapolu
authors: Krishna
authors: K
authors: Sanka
authors: Praveen Kumar
authors: PK
authors: Vemula
authors: Vinaydas
authors: V
authors: Aatipamula
authors: Abdul Bari
authors: AB
authors: Mohd
authors: Prakash V
authors: PV
authors: Diwan
mesh_terms: D000890:Anti-Infective Agents / Q000008:administration & dosage* / Q000737:chemistry; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D004339:Drug Compounding / Q000379:methods; D016503:Drug Delivery Systems; D004355:Drug Stability; D004356:Drug Storage; D005079:Excipients / Q000737:chemistry*; D065347:Hypromellose Derivatives; D008747:Methylcellulose / Q000031:analogs & derivatives / Q000737:chemistry; D008795:Metronidazole / Q000008:administration & dosage* / Q000737:chemistry; D017693:Sodium Bicarbonate / Q000737:chemistry; D013997:Time Factors
chemical_list: D000890:Anti-Infective Agents; D005079:Excipients; D008795:Metronidazole; D065347:Hypromellose Derivatives; D017693:Sodium Bicarbonate; D008747:Methylcellulose; D002266:Carboxymethylcellulose Sodium