Method and apparatus for buffering anesthetics

A method, comprising:

• providing a device comprising;
• a buffer compartment comprising a plunger and containing a buffer;
• an anesthetic compartment configured to receive an anesthetic cartridge comprising a septum and containing an anesthetic;
• a needle assembly comprising a transfer needle having a first end and a second end;
• and
• a mechanism that prevents the plunger in the buffer cartridge from moving outward.
• inserting an anesthetic cartridge, comprising a septum and containing an anesthetic into the anesthetic compartment;
• causing the second end of the transfer needle to penetrate the septum and the plunger to be moved into the buffer compartment, whereby;
• buffer is transferred from the buffer compartment via the transfer needle into the anesthetic cartridge.

A method, comprising:

• providing a device comprising:
• a buffer compartment comprising a plunger and containing a buffer;
• an anesthetic compartment configured to receive an anesthetic cartridge comprising an end that comprises a septum and containing an anesthetic;
• a needle assembly, comprising a transfer needle having a first end and a second end;
• and
• an advancer member;
• inserting the anesthetic cartridge into the anesthetic compartment, wherein the second end of the transfer needle penetrates the septum, the anesthetic cartridge end that comprises a septum contacts the advancer member and the advancer member engages with the plunger;
• applying force to the anesthetic cartridge causing advancement of the advancer member and movement of the plunger into the buffer compartment to expel buffer from the buffer cartridge into the anesthetic cartridge via the transfer needle.

A method for preparing an anesthetic that is substantially isosmotic, comprising:

• providing a device comprising;
• a buffer compartment comprising a plunger and containing a buffer;
• an anesthetic compartment;
• a needle assembly comprising a transfer needle having a first end and a second end;
• and
• a mechanism that prevents the plunger in the buffer cartridge from moving outward.
• inserting an anesthetic cartridge, comprising a septum and containing an anesthetic into the anesthetic compartment;
• causing the second end of the transfer needle to penetrate the septum and the plunger to be moved into the buffer compartment, whereby;
• buffer is transferred from the buffer compartment via the transfer needle into the anesthetic cartridge, resulting in the anesthetic being substantially isosmotic.