title: Buccoadhesive films for once-a-day administration of rivastigmine: systematic formulation development and pharmacokinetic evaluation.
abstract: BACKGROUND
  Rivastigmine, an anti-Alzheimer's drug, suffers from major predicaments like low oral bioavailability, severe GI adverse effects related to rapid fluctuations in drug plasma levels, and high frequency of dosing.
  
  
  OBJECTIVE
  The present investigation aims at developing buccoadhesive films capable of delivering the drug in vivo in a sustained manner. Augmentation of drug bioavailability by the avoidance of first-pass effect through the buccal route and reduction in GI side effects would be other key advantages of this system.
  
  
  METHODS
  Buccoadhesive films of rivastigmine were systematically designed and evaluated for in vitro drug release, ex vivo buccal permeation and ex vivo buccoadhesive strength. Optimal composition of the polymer blends was rationally chosen using a central composite design and overlay plot. In vivo pharmacokinetic studies were carried out in rabbits, and attempts were made to establish in vitro/ in vivo correlations (IVIVC).
  
  
  RESULTS
  Besides possessing the requisite drug release regulation, the optimized formulation exhibited excellent buccoadhesion, and buccal permeation. Pharmacokinetic studies indicated extension of plasma drug levels and level A of IVIVC was successfully established.
  
  
  CONCLUSIONS
  Excellent buccal bioadhesion and transmucosal permeation, coupled with drug release control, ratify the potential of the optimized formulation to deliver the drug in a controlled and site-specific manner. Successful establishment of IVIVC substantiated the judicious choice of in vitro dissolution media for simulating the in vivo conditions.
  
  
  CONCLUSIONS
  Besides unraveling the polymer synergism, the study helped in developing an optimal once-a-day buccoadhesive drug delivery system exhibiting excellent trans-buccal permeation and buccoadhesive characteristics with improved bioavailability potential.
authors.affiliation: University Institute of Pharmaceutical Sciences (UGC Centre of Advanced Studies), Panjab University, Chandigarh, India.
authors.forename: Rishi
authors.initials: R
authors.lastname: Kapil
authors.forename: Sanju
authors.initials: S
authors.lastname: Dhawan
authors.forename: Sarwar
authors.initials: S
authors.lastname: Beg
authors.forename: Bhupinder
authors.initials: B
authors.lastname: Singh
mesh_terms: D000268:Adhesiveness; D000278:Administration, Buccal; D000818:Animals; D001682:Biological Availability; D002626:Chemistry, Pharmaceutical; D002800:Cholinesterase Inhibitors / Q000008:administration & dosage / Q000493:pharmacokinetics*; D016503:Drug Delivery Systems; D009061:Mouth Mucosa / Q000378:metabolism*; D048448:Phenylcarbamates / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011817:Rabbits; D000068836:Rivastigmine
chemical_list: D002800:Cholinesterase Inhibitors; D048448:Phenylcarbamates; D000068836:Rivastigmine