title: Benefits of polidocanol endovenous microfoam (Varithena®) compared with physician-compounded foams.
abstract: OBJECTIVE
  To compare foam bubble size and bubble size distribution, stability, and degradation rate of commercially available polidocanol endovenous microfoam (Varithena®) and physician-compounded foams using a number of laboratory tests.
  
  
  METHODS
  Foam properties of polidocanol endovenous microfoam and physician-compounded foams were measured and compared using a glass-plate method and a Sympatec QICPIC image analysis method to measure bubble size and bubble size distribution, Turbiscan™ LAB for foam half time and drainage and a novel biomimetic vein model to measure foam stability. Physician-compounded foams composed of polidocanol and room air, CO2, or mixtures of oxygen and carbon dioxide (O2:CO2) were generated by different methods.
  
  
  RESULTS
  Polidocanol endovenous microfoam was found to have a narrow bubble size distribution with no large (>500 µm) bubbles. Physician-compounded foams made with the Tessari method had broader bubble size distribution and large bubbles, which have an impact on foam stability. Polidocanol endovenous microfoam had a lower degradation rate than any physician-compounded foams, including foams made using room air (p < 0.035). The same result was obtained at different liquid to gas ratios (1:4 and 1:7) for physician-compounded foams. In all tests performed, CO2 foams were the least stable and different O2:CO2 mixtures had intermediate performance. In the biomimetic vein model, polidocanol endovenous microfoam had the slowest degradation rate and longest calculated dwell time, which represents the length of time the foam is in contact with the vein, almost twice that of physician-compounded foams using room air and eight times better than physician-compounded foams prepared using equivalent gas mixes.
  
  
  CONCLUSIONS
  Bubble size, bubble size distribution and stability of various sclerosing foam formulations show that polidocanol endovenous microfoam results in better overall performance compared with physician-compounded foams. Polidocanol endovenous microfoam offers better stability and cohesive properties in a biomimetic vein model compared to physician-compounded foams. Polidocanol endovenous microfoam, which is indicated in the United States for treatment of great saphenous vein system incompetence, provides clinicians with a consistent product with enhanced handling properties.
authors.affiliation: Bioengineering Science Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK Electro-Mechanical Engineering Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK.
authors.forename: Dario
authors.initials: D
authors.lastname: Carugo
authors.affiliation: Electro-Mechanical Engineering Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK.
authors.forename: Dyan N
authors.initials: DN
authors.lastname: Ankrett
authors.affiliation: Bioengineering Science Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Bioengineering Science Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK Institute for Life Sciences, University of Southampton, Southampton, UK.
authors.forename: Xunli
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Electro-Mechanical Engineering Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK Institute for Life Sciences, University of Southampton, Southampton, UK.
authors.forename: Martyn
authors.initials: M
authors.lastname: Hill
authors.affiliation: Biocompatibles UK Ltd., A BTG International group company, Farnham, Surrey, UK.
authors.forename: Vincent
authors.initials: V
authors.lastname: O'Byrne
authors.affiliation: Biocompatibles UK Ltd., A BTG International group company, Farnham, Surrey, UK.
authors.forename: James
authors.initials: J
authors.lastname: Hoad
authors.affiliation: Biocompatibles UK Ltd., A BTG International group company, Farnham, Surrey, UK.
authors.forename: Mehreen
authors.initials: M
authors.lastname: Arif
authors.affiliation: BTG International Ltd., London, UK.
authors.forename: David D I
authors.initials: DD
authors.lastname: Wright
authors.affiliation: Biocompatibles UK Ltd., A BTG International group company, Farnham, Surrey, UK Andrew.Lewis@btgplc.com.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Lewis
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D000077423:Polidocanol; D011092:Polyethylene Glycols / Q000737:chemistry*; D012597:Sclerosing Solutions / Q000737:chemistry*
chemical_list: D012597:Sclerosing Solutions; D000077423:Polidocanol; D011092:Polyethylene Glycols
keywords: Foam drainage times; biomimetic analysis method; bubble size; bubble size distribution; foam half time; physician-compounded foams; polidocanol endovenous microfoam; polidocanol injectable foam; sclerotherapy; varicose veins