title: Chitosan-Hydroxypropyl Methylcellulose Matrices as Carriers for Hydrodynamically Balanced Capsules of Moxifloxacin HCl.
abstract: BACKGROUND
  In recent years, gastroretentive, hydrodynamically balanced system (HBS) for stomach-specific floating sustained drug release has gained a lot of importance in improving absorption of drugs especially those absorbed from stomach and small intestine.
  
  
  OBJECTIVE
  The objective of the current investigation is to evaluate chitosan-hydroxypropyl methylcellulose (HPMC) based on polymeric matrices as a carrier for single-unit capsules based on HBS for stomach- specific floating sustained drug release using moxifloxacin HCl (MX) as a model drug.
  
  
  METHODS
  Various HBS capsules of MX were prepared by physical blending of MX with chitosan (low or medium molecular mass) or HPMC (K4M or K15M) or chitosan-HPMC combinations in varying proportions followed by encapsulation into size 0 capsules made of hard gelatin. The in vitro buoyancy and drug release in 0.1 N HCl (pH 1.2) were evaluated.
  
  
  RESULTS
  HBS capsules based on chitosan (low and medium molecular weight and their combination) as polymer matrix failed to float on 0.1 N HCl (pH 1.2). Whereas, formulations containing HPMC (K4M or K15M) or their mixture with chitosan, remained buoyant and released MX over 9 h in the acidic dissolution medium following zero-order kinetics.
  
  
  CONCLUSIONS
  HPMC (K4M, K15M, blend of K4M and K15M) or their mixture with low/medium molecular mass chitosan may constitute excellent carrier systems for the stomach-specific sustained delivery of MX over a longer period.
authors.forename: Anurag
authors.initials: A
authors.lastname: Verma
authors.forename: Juhi
authors.initials: J
authors.lastname: Dubey
authors.forename: Navneet
authors.initials: N
authors.lastname: Verma
authors.affiliation: Department of Pharmaceutics, Seemanta Institute of Pharmaceutical Sciences, Mayurbhanj-757086, Odisha, India.
authors.forename: Amit Kumar
authors.initials: AK
authors.lastname: Nayak
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry*; D065546:Drug Liberation; D024841:Fluoroquinolones / Q000008:administration & dosage / Q000737:chemistry*; D057446:Hydrodynamics; D065347:Hypromellose Derivatives / Q000737:chemistry*; D015394:Molecular Structure; D000077266:Moxifloxacin
chemical_list: D004337:Drug Carriers; D024841:Fluoroquinolones; D065347:Hypromellose Derivatives; D048271:Chitosan; D000077266:Moxifloxacin
keywords: Chitosan; HPMC; drug release; hydrodynamically balanced system