Therapeutic microfoam

Abstract

Improved therapeutic sclerosing microfoams are provided that have advantage in producing a consistent profile injectable foam with minimal input by the physician yet using high volume percentages of blood dispersible gases, thus avoiding use of potentially hazardous amounts of nitrogen.

1 . A microfoam comprising a physiologically acceptable gas that is dispersible in blood and an aqueous sclerosant liquid characterized in that the microfoam has a density of from 0.07 to 0.19 g/cm 3  and is capable of being passed down a 21 gauge needle without reverting back to gas and liquid by more than 10%, based on liquid content reverting back to unfoamed liquid phase.  
     
     
         2 . A microfoam comprising a physiologically acceptable gas that is dispersible in blood and an aqueous sclerosant liquid characterized in that the microfoam has a density of from 0.07 to 0.19 g/cm 3  and is capable of being passed down a 21 gauge needle such that 50% or more by number of its gas bubbles of at least 25 μm remain at 150 μm diameter or less and at least 95% of these bubbles at 280 μm diameter or less.  
     
     
         3 . A microfoam as claimed in  claim 1  or  claim 2  characterized in that it has a half-life as measured by drainage through a funnel of 1 cm neck diameter of at least 2 minutes, more preferably 2.5 minutes and most preferably 3 minutes:  
     
     
         4 . A microfoam as claimed in any preceding claim characterized in that the gas includes less than 40% v/v nitrogen.  
     
     
         5 . A microfoam as claimed in any preceding claim characterized in that the density is from 0.09 to 0.16 g/mL.  
     
     
         6 . A microfoam as claimed in any preceding claim characterized in that 50% or more by number of the gas bubbles of at least 25 μm diameter are of no more than 120 μm diameter and at least 95% of these gas bubbles are of no more than 250 μm.  
     
     
         7 . A microfoam as claimed in any preceding claim characterized in that it is of density of from 0.11 to 0.14 g/cm 3 .  
     
     
         8 . A microfoam as claimed in any preceding claim characterized in that the gas comprises at least 50% oxygen or carbon dioxide.  
     
     
         9 . A microfoam as claimed in any preceding claim characterized in that the sclerosant liquid is aqueous polidocanol or sodium tetradecyl sulfate.  
     
     
         10 . A microfoam as claimed in  claim 9  characterized in that the sclerosant is aqueous polidocanol, the concentration of polidocanol being is from 0.5 to 4% vol/vol in the liquid.  
     
     
         11 . A microfoam as claimed in  claim 9  or  claim 10  characterized in that sclerosant is made up in water or saline solution.  
     
     
         12 . A microfoam as claimed in  claim 11  characterized in that the saline is phosphate buffered saline pH 6.0 to pH 8.0.  
     
     
         13 . A microfoam as claimed in  claim 10 ,  11  or  12  characterized in that the aqueous solution contains a minor amount of alcohol.  
     
     
         14 . A microfoam as claimed in any preceding claim characterized in that it contains 1 to 10% vouvol glycerol.  
     
     
         15 . A method of treating a patient in need of sclerotherapy of a blood vessel comprising administering a microfoam as claimed in any preceding claim to that blood vessel.