Stable microbubbles suspensions injectable into living organisms

Abstract

Gas or air filled microbubble suspensions in aqueous phases usable as imaging contrast agents in ultrasonic echography. They contain laminarized surfactants and, optionally, hydrophilic stabilizers. The laminarized surfactants can be in the form of liposomes. The suspensions are obtained by exposing the laminarized surfactants to air or a gas before or after admixing with an aqueous phase.

1 - 27 . (canceled)  
     
     
         28 . A composition suitable for injection into the bloodstream and body cavities of living beings, 
 said composition comprising a suspension of stabilized gas microbubbles in a physiologically acceptable aqueous carrier phase having from 0.01 to about 20% by weight of one or more dissolved or dispersed surfactants,    at least one of said surfactants being a film-forming surfactant present in a composition at least partially in lamellar or laminar form, in which the surfactant comprises, bound thereto, bioactive species designed for specific targeting purposes,    wherein the gas in said gas microbubbles comprises a freon.    
     
     
         29 . The composition of  claim 28 , wherein the bioactive species is selected from the group consisting of monoclonal antibodies, antibody fragments or polypeptides designed to mimic antibodies, bioadhesive polymers, lectins and other receptor recognizing molecules.  
     
     
         30 . The composition of  claim 28 , wherein said film forming surfactant is a phospholipid.  
     
     
         31 . An ultrasound contrast agent comprising an aqueous solution and phospholipid stabilized microbubbles, 
 the phospholipid stabilized microbubbles containing gas wherein the gas is stabilized by phospholipids in lamellar or laminar form at the gas/liquid interface, and    the phospholipids comprise bound thereto bioactive species designed for specific targeting purposes.    
     
     
         32 . The ultrasound contrast agent of  claim 31 , wherein the bioactive species is selected from the group consisting of monoclonal antibodies, antibody fragments or polypeptides designed to mimic antibodies, bioadhesive polymers, lectins and other receptor recognizing molecules.  
     
     
         33 . The composition of  claim 31 , wherein the gas comprise a freon.  
     
     
         34 . The composition of  claim 31 , wherein the gas is selected from the group consisting of CO 2 , nitrogen, N 2 O, methane and butane.  
     
     
         35 . The composition of  claim 31 , wherein the gas is a radioactive gas.  
     
     
         36 . The composition of  claim 35 , wherein the radioactive gas is  133 Xe or  81 Kr.