Syringe assembly and method for lyophilizing and reconstituting injectable medication

A syringe assembly comprising:

• a syringe barrel having an open proximal end, a distal end and a substantially cylindrical chamber wall extending therebetween to define a fluid receiving chamber, a passage extending through said distal end and communicating with said chamber;
• a stopper dimensioned and disposed for sliding fluid-tight engagement in said chamber of said syringe barrel, said stopper having opposed proximal and distal ends;
• means for releasably sealing said passage to isolate said chamber from the environment;
• an elongate plunger rod having a proximal end and a distal end engaging said proximal end of said stopper;
• and
• a flow channelizer slidably disposed in said chamber of said syringe barrel between said stopper and said distal end of said syringe barrel, said flow channelizer having opposed proximal and distal ends and at least one fluid flow channel extending therebetween, whereby distally directed forces on said plunger rod urge said stopper and said flow channelizer in a distal direction in said syringe barrel, whereby proximally directed forces on said plunger rod cause said stopper to move proximally and away from said flow channelizer to define a mixing chamber therebetween in fluid communication with said at least one fluid flow channel.

A process for lyophilizing an injectable medication, said process comprising the steps of:

• providing a syringe barrel with an open proximal end, a distal end and a cylindrical chamber wall extending therebetween and defining a fluid receiving chamber, a tip projecting from said distal end of said syringe and having a passage extending therethrough and communicating with said chamber;
• sealing said passage in said tip;
• placing a liquid medication in said chamber;
• providing a plunger assembly having a distally disposed flow channelizer with opposed proximal and distal ends and at least one fluid flow channel extending therebetween and a stopper dimensioned for sliding fluid-tight engagement with said cylindrical chamber wall and disposed adjacent said flow channelizer and proximally thereof;
• inserting said flow channelizer of said plunger assembly into said proximal end of said syringe barrel;
• lyophilizing said liquid medication in said chamber;
• and
• urging said plunger assembly distally into said syringe barrel such that said stopper thereof seals said lyophilized medication in said chamber.