Methods and devices for sterilizing and holding buffering solution cartridges
Trays comprising a base have a plurality of axial slots adapted to receive buffer or other medical solution containers within the slots. A spring or other compression element at the bottom of the slot is configured to engage a plunger at the bottom of the solution container when present in the slot so that pressure is applied to the contents of the container in order to stabilize the contents while the containers are sterilized at an elevated temperature.
1. A method for sterilizing a container filled with a medical solution comprising a buffer, which solution evolves vapor when heated, said method comprising:
providing a sealed container having an open interior filled with the medical solution, a needle-penetrable septum, and a plunger;
applying a pressure above atmospheric pressure to the medical solution within the sealed container by engaging a compression member against the plunger; and
exposing the container to an elevated temperature sufficient to sterilize the medical solution within the container,
wherein said temperature is sufficient to evolve the vapor at atmospheric pressure, and the applied pressure is sufficient to inhibit the evolution of the vapor within the container without precipitating the buffer.
2. A method as in claim 1 , wherein the applied pressure allows for thermal expansion of the solution during sterilization, such that the solution does not achieve a pressure sufficient to cause the transformation of components of the solution to solid form.
3. A method as in claim 1 , wherein the buffer is sodium bicarbonate, the sterilization temperature is in the range from 100° C. to 150° C., and the pressure applied to the solution before, during, and after autoclaving is at least 0.7 kPa (14.7 psig) but not more than 8.3 kPa (175 psig).
4. A method as in claim 3 , wherein the container is exposed to the elevated temperature and the applied pressure for a time in the range from 3 minutes to 60 minutes.
5. A method as in claim 1 , wherein a plurality of containers are held in a tray having a plurality of compression members arranged to engage the plungers to apply said pressure.
6. A method as in claim 5 , wherein the applied pressure allows for thermal expansion of the solution during sterilization, such that the solution does not achieve a pressure sufficient to cause the transformation of the components of the solution to solid form.
7. A method as in claim 2 , wherein the buffer is sodium bicarbonate, the sterilization temperature is in the range from 100° C. to 150° C., and the pressure applied to the solution before, during, and after autoclaving is a least 0.7 kPa (14.7 psig) but not more than 8.3 kPa (175 psig).
8. A method as in claim 7 , wherein the container is exposed to the elevated temperature and the applied pressure for a time in the range from 3 minutes to 60 minutes.