title: The CAM-LDPI method: a novel platform for the assessment of drug absorption.
abstract: OBJECTIVE
  This study aimed to explore the use of the chicken chorioallantoic membrane (CAM) with laser doppler perfusion imaging (LDPI) as a platform to assess absorption of vasoactive drugs.
  
  
  METHODS
  The optimal age of the CAM to be employed in the test and the indicator of vasoactivity were first established. Test substances that included common solvents and vasoactive drugs were tested on the CAM surface to determine their irritancy and blood perfusion effects.
  
  
  RESULTS
  Insignificant changes in blood perfusion were observed with deionized water, 0.9% w/v soldium chloride and 5% w/v glucose monohydrate, as well as theophylline and glucagon. Complex changes in blood perfusion were detected with ethanol, N-methyl-2-pyrrolidone, glycerin and propranolol. Both caffeine and glyceryl trinitrate resulted in a drop in blood perfusion.
  
  
  CONCLUSIONS
  It was concluded that the LDPI offers a rapid and non-invasive method to measure blood perfusion in the CAM. The latter provides a potentially useful platform in formulation studies to evaluate the effects of additives on drug absorption using caffeine or glyceryl trinitrate as model drugs.
authors.affiliation: Department of Pharmacy, National University of Singapore, Singapore.
authors.forename: Stephanie Li Mei
authors.initials: SL
authors.lastname: Tay
authors.forename: Paul Wan Sia
authors.initials: PW
authors.lastname: Heng
authors.forename: Lai Wah
authors.initials: LW
authors.lastname: Chan
mesh_terms: D000818:Animals; D002110:Caffeine / Q000493:pharmacokinetics / Q000494:pharmacology; D002642:Chick Embryo; D002645:Chickens; D049033:Chorioallantoic Membrane / Q000098:blood supply; D005079:Excipients / Q000494:pharmacology*; D017078:Laser-Doppler Flowmetry / Q000379:methods*; D005996:Nitroglycerin / Q000493:pharmacokinetics / Q000494:pharmacology; D012039:Regional Blood Flow; D012997:Solvents / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000493:pharmacokinetics / Q000494:pharmacology*
chemical_list: D005079:Excipients; D012997:Solvents; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D002110:Caffeine; D005996:Nitroglycerin