Ejection liquid, ejection method, method of making droplets from liquid, cartridge and ejection device

Abstract

The present invention provides a liquid composition, as an ejection liquid used for stably ejecting liquid droplets, including at least one kind of a protein and a peptide, and a compound having a betaine skeleton by application of thermal energy to the liquid; a method of making droplets form the liquid; and an ejection method and an ejection device suitable for utilizing protein liquid droplets. By adding a compound having a betaine skeleton to an aqueous solution of at least one kind of a protein and a peptide, the liquid composition is improved in stability for ejection by application of thermal energy. Further, a surfactant may be further added to the liquid composition containing the compound having a betaine skeleton, and in this case the effect of stable ejection can be obtained.

1 . An ejection liquid comprising at least one kind of a protein and a peptide, which is ejected by application of thermal energy thereto, and further comprising a compound having a betaine skeleton with a surface-active property, and a liquid medium mainly composed of water. 
   
   
       2 . The ejection liquid according to  claim 1 , wherein the compound having a betaine skeleton is a compound represented by the following formula (1): 
     
       
         
         
             
             
         
       
       wherein R 1  represents a substituted or unsubstituted alkyl group having 6 to 18 carbon atoms; 
       R 2  and R 5  represent an alkylene chain having 1 to 6 carbon atoms; 
       R 3  and R 4  represent an alkyl group or alkylene chain having 1 to 6 carbon atoms; 
       R 3  and R 4  may be bonded with each other to form a heterocyclic ring; 
       A represents a carboxylic group, a sulfonic group or an anion; 
       X 1  and X 2  represent a counter ion; and 
       n represents 0 or 1. 
     
   
   
       3 . The ejection liquid according to  claim 1  or  2 , wherein the compound having a betaine skeleton is at least one compound selected from the group consisting of alkylamide alkylbetaine and a salt thereof, and a derivative thereof. 
   
   
       4 . The ejection liquid according to any one of  claims 1  to  3 , wherein the protein and the peptide are a substance selected from the group consisting of calcitonin, insulin, glucagon, interferon, a protease inhibitor, cytokine, a growth hormone, a hematopoietic factor protein, an antibody, and an analogue thereof, and a derivative thereof. 
   
   
       5 . The ejection liquid according to any one of  claims 1  to  4 , further comprising a surfactant. 
   
   
       6 . The ejection liquid according to  claim 5 , wherein the surfactant is polyoxyethylene sorbitan fatty acid ester. 
   
   
       7 . An ejection method comprising ejecting an ejection liquid according to any one of  claims 1  to  6 , based on the principle of an ink jet system. 
   
   
       8 . An ejection method comprising ejecting an ejection liquid according to any one of  claims 1  to  6 , based on the principle of a thermal ink jet system. 
   
   
       9 . A liquid ejection cartridge comprising a tank for accommodating an ejection liquid according to any one of  claims 1  to  6 , and an ejection head based on the principle of a thermal ink jet system. 
   
   
       10 . An ejection device comprising: a liquid ejection cartridge according to  claim 9 ; a flow path for guiding a liquid accommodated in the cartridge to be ejected from a liquid ejection part of the head of the cartridge according to  claim 9  and guiding airflow for transporting the liquid; and an opening. 
   
   
       11 . The ejection device according to  claim 10 , wherein the ejection device is used for inhalation. 
   
   
       12 . A method of making droplets from a liquid containing at least one kind of a protein and a peptide by applying thermal energy to the liquid, wherein the liquid further comprises a compound having a betaine skeleton with a surface-active property. 
   
   
       13 . The method of making droplets from the liquid according to  claim 12 , wherein the protein and the peptide are a substance selected from the group consisting of calcitonin, insulin, glucagon, interferon, a protease inhibitor, cytokine, a growth hormone, hematopoietic factor protein, an antibody, an analogue thereof and a derivative thereof. 
   
   
       14 . The method of making droplets from the liquid according to  claim 12  or  13 , wherein the liquid further comprises a surfactant. 
   
   
       15 . The method of making droplets from the liquid according to any one of  claims 12  to  14 , wherein the method makes liquid droplets from the liquid by applying thermal energy to the liquid based on the principle of a thermal ink jet system