System and method for filling containers with liquid under varying pressure conditions

Abstract

A system and method for filling a container such as a syringe or vial with liquid is provided. Also provided is a system and method for closing a filled container with a stopper or piston gas-pocket free. The systems and methods are carried out at a minimum of two different pressure levels to provide filled and/or closed containers substantially without formation of gas pockets or foaming in the container. Also provided is a system and method for degassing liquid useful in the filling and closing processes.

1 . A system for filling a container with liquid, comprising: 
 a dosing unit for supplying the liquid to the container;    a filling head for receiving the liquid from the dosing unit and transferring the liquid to inside of the container when the filling head engages the container; and    a vacuum pump connected to the filling head for providing vacuum to inside of the container;    wherein a pressure inside the container is regulated to at least two different pressure levels during transfer of the liquid through the filling head.    
   
   
       2 . The system of  claim 1 , where the two different pressure levels include ambient pressure and a pressure of the vacuum supplied by the vacuum pump.  
   
   
       3 . The system of  claim 1 , further comprising a filling needle received in the filling head, the filling needle delivering the liquid to inside of the container.  
   
   
       4 . The system of  claim 3 , wherein the filling needle is received inside the container.  
   
   
       5 . The system of  claim 4 , wherein the dosing unit is connected to the filling needle for supplying the liquid in a predetermined dose to the filling needle.  
   
   
       6 . The system of  claim 5 , further comprising a pressure sensitive membrane provided between the dosing unit and the filling needle to control transfer of the liquid.  
   
   
       7 . The system of  claim 1 , wherein the filling head includes a seal for engaging the container.  
   
   
       8 . The system of  claim 1 , further comprising a gas connection for delivering the vacuum from the vacuum pump to the filling head.  
   
   
       9 . The system of  claim 8 , wherein the gas connection includes a pressure release connection.  
   
   
       10 . The system of  claim 1 , wherein the container is defined by a rigid body.  
   
   
       11 . The system of  claim 10 , wherein the rigid body is filled substantially without foaming of the liquid.  
   
   
       12 . The system of  claim 1 , wherein the liquid is a pharmaceutical or diagnostic liquid.  
   
   
       13 . A method for filling a container with liquid, comprising the steps of: 
 providing the container with an open end for receiving the liquid;    engaging a filling head with the container such that the filling head and the container form a seal;    opening a vacuum source to inside of the container, thereby reducing the pressure to a first pressure level;    supplying a portion of a predetermined dose of the liquid from a dosing unit to inside of the container through the filling head;    closing the vacuum source, thereby raising the pressure inside the container from the first pressure level to a second pressure level; and    supplying a remainder of the predetermined dose of the liquid from the dosing unit to inside of the container such that the container is filled substantially without formation of gas pockets in the container.    
   
   
       14 . The method of  claim 13 , wherein the container is a syringe having a top portion with the open end and a bottom portion defining a cone.  
   
   
       15 . The method of  claim 14 , wherein during the step of closing the vacuum source, the liquid is forced into the cone of the syringe.  
   
   
       16 . The method of  claim 13 , wherein during the step of supplying the portion of the predetermined dose, foam is formed in the container, and during the step of closing the vacuum source and raising the pressure in the container, the foam is substantially collapsed in the container.  
   
   
       17 . A method for closing a container containing liquid, comprising the steps of: 
 providing the container with an open end for receiving a piston;    engaging an insertion tool having a first seal with the container, the insertion tool having a duct for receiving the piston, and the piston in the duct forming a second seal;    applying vacuum to inside of the container, thereby reducing the pressure to a lower pressure level;    operating a pressing tool to force the piston through the duct; and    releasing the piston out of the duct and into the container, wherein a pressure difference across the piston drives the piston into the container until the piston reaches a surface of the liquid.    
   
   
       18 . A system for closing a container containing liquid, comprising: 
 an insertion tool having a first seal for engaging with the container;    a duct extending through the insertion tool for receiving a piston; and    a vacuum pump for applying vacuum in the container to reduce a pressure level and cause the piston to be transferred through the duct until the piston reaches a surface of the liquid.    
   
   
       19 . The system of  claim 18 , wherein the vacuum pump is operated continuously.  
   
   
       20 . A system for degassing a liquid, comprising: 
 a pressure vessel enclosing a soft bag, the pressure vessel being regulated to at least two different pressure levels;    a liquid source for supplying a predetermined dose of liquid to the soft bag; and    a vacuum pump connected to the pressure vessel for providing vacuum to inside of the pressure vessel, wherein the vacuum reduces the pressure in the soft bag and causes gas to separate from degassed liquid in the soft bag, the separated gas being removable upon reaching equilibrium of the gas in the liquid.    
   
   
       21 . The system of  claim 20 , wherein the degassed liquid is removed from the soft bag prior to removal of the separated gas.  
   
   
       22 . The system of  claim 20 , wherein the soft bag has a single outlet, the outlet being connected to a pipe for liquid and gas transfer.