title: Transbuccal delivery of acyclovir (II): feasibility, system design, and in vitro permeation studies.
abstract: OBJECTIVE
  To design a buccal mucoadhesive system for systemic delivery of acyclovir using a novel mucoadhesive, copolymers of acrylic acid and poly(ethylene glycol), and to determine the feasibility of transbuccal delivery of acyclovir using this system.
  
  
  METHODS
  The buccal delivery system was prepared using an adhesive, a copolymer of acrylic acid and poly(ethylene glycol) monomethylether monomethacrylate, and an impermeable membrane to prevent excessive washout by saliva and to attain unidirectional release. Acyclovir was loaded into the copolymer film prior to lamination of backing material. In vitro drug release studies were conducted in isotonic McIlvaine buffer solution. Buccal permeation of acyclovir was investigated using porcine buccal mucosa with side-by-side flow through diffusion cells at 37;C. Acyclovir was quantified using HPLC.
  
  
  RESULTS
  Buccal permeation of acyclovir from the mucoadhesive delivery system was controlled for up to 20 hours with a time lag (t(lag)) of 10.4 hours and a steady state flux of 144.2 microg/cm(2)/h. With the incorporation of NaGC into the system t(lag) was shortened to 5.6 hours with an enhanced steady state flux of 758.7 microg/cm(2)/h. Sustained delivery of acyclovir across bucccal mucosa using this mucoadhesive system was maintained for up to 22 hours.
  
  
  CONCLUSIONS
  The mucoadhesive system of P(AA-co-PEG) was shown to be a good candidate for controlled oral mucosal delivery of acyclovir. Buccal delivery of acyclovir was proven feasible based on in vitro permeation studies.
authors.affiliation: Department of Pharmaceutics and Medicinal Chemistry, School of Pharmacy and Health Sciences, University of the Pacific, 3601 Pacific Avenue, Stockton, California 95211, USA. ashojaei@pharmacy.ualberta.ca
authors.forename: A H
authors.initials: AH
authors.lastname: Shojaei
authors.forename: S L
authors.initials: SL
authors.lastname: Zhuo
authors.forename: X
authors.initials: X
authors.lastname: Li
mesh_terms: D000179:Acrylates / Q000737:chemistry; D000212:Acyclovir / Q000737:chemistry / Q000493:pharmacokinetics*; D000269:Adhesives; D000278:Administration, Buccal; D000818:Animals; D000998:Antiviral Agents / Q000737:chemistry / Q000493:pharmacokinetics*; D004337:Drug Carriers; D020100:Hydrogels; D066298:In Vitro Techniques; D008567:Membranes, Artificial; D009061:Mouth Mucosa / Q000378:metabolism*; D010539:Permeability; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D013552:Swine
chemical_list: D000179:Acrylates; D000269:Adhesives; D000998:Antiviral Agents; D004337:Drug Carriers; D020100:Hydrogels; D008567:Membranes, Artificial; D011108:Polymers; D011092:Polyethylene Glycols; D000212:Acyclovir