METHODS AND SYSTEMS FOR ADJUSTING THE pH OF MEDICAL BUFFERING SOLUTIONS

• US 20110005958A1
• Filed: 04/23/2010
• Published: 01/13/2011
• Est. Priority Date: 07/09/2009
• Status: Abandoned Application

• Current Assignee: Onpharma Inc. (Bausch Health Cos., Inc.)
• Original Assignee: Onpharma Inc. (Bausch Health Cos., Inc.)
• Inventors: Stepovich, Matthew J., Nguyen, Harry, Falkel, Michael I.
• Application Number:
  US12/766,259
• Publication Number:
  US 20110005958A1
• Time in Patent Office: Days
• US Class Current: 206/524.1
• CPC Class Codes: G05D 21/02 characterised by the use of electric means

Abstract

Buffer solutions within a plurality of containers can be adjusted and controlled by exposing the containers while open to a controlled environment. In particular, an inventory of containers holding bicarbonate buffers can be adjusted to a precisely controlled pH by exposing the containers while open to a controlled carbon dioxide environment in a treatment chamber.

Claims

1. A method for adjusting pH in a plurality of buffer containers, said method comprising:

positioning each of the containers in a chamber with the container open to expose the buffer to an atmosphere in the chamber;

controlling the pressure, temperature, and CO₂ level of the atmosphere to values selected to provide a target equilibrium pH of the buffer;

holding the containers in the controlled atmosphere of the chamber for a time sufficient for the buffer in each of the containers to reach the target pH; and

sealing each of the containers to inhibit changes in pH over time.

2. A method as in claim 1, further comprising moving the containers within the chamber to promote mixing of the atmosphere and mixing of the buffer solution.

3. A method as in claim 1, wherein controlling the pressure, temperature, and CO₂ level of the atmosphere comprises introducing, circulating, and removing gas from the chamber.

4. A method as in claim 3, wherein the gas is introduced and removed at a substantially constant flow rate.

5. A method as in claim 4, wherein the flow rate is in the range from 0.1V to 1V per hour, where V is the open internal volume of the chamber.

6. A method as in claim 1, wherein the open containers are held in the chamber for at least 24 hours.

7. A method as in claim 6, wherein the open containers are held in the chamber for a time in the range from 24 hours to 96 hours.

8. A method as in claim 1, wherein the temperature is in the range from 70°

C. to 74°

C., the pressure is with 1% of atmospheric, and the CO₂ content is at least 97% by volume, providing a pH in the range from 7.63 to 7.75

9. A method as in claim 1, wherein the gas has a 100% relative humidity when introduced to the chamber.

10. A method as in claim 1, wherein at least some of the containers include a volume of water which evaporates during the period of time when the container is held in the chamber to raise the relative humidity within the chamber.

11. A method as in claim 1, wherein the container is sealed with no headspace remaining after sealing.

12. A method as in claim 11, wherein the container is entirely filled while in the chamber.

13. A method as in claim 11, wherein the container is partially filled to increase the available open surface area while in the chamber and completely filled prior to sealing.

14. A method as in claim 13, wherein the container is completely filled by reducing the volume within the container.

15. A method as in claim 1, wherein all containers are identical in shape and volume.

16. A method as in claim 1, wherein the containers are sealed while within the chamber.

17. A method as in claim 1, wherein the containers are removed from the chamber and then sealed.

18. A system for adjusting the pH of a plurality of buffer containers, said system comprising:

a chamber having a perimeter wall and an interior;

a gas supply connected to deliver a gas flow into the interior of the chamber, wherein the gas flow comprises at least about 97% by volume carbon dioxide;

a plurality of spaced-apart supports within the interior of the chamber; and

a multiplicity of pneumostatic passages formed through the perimeter wall and located to allow buffer containers to be placed on and removed from each of the supports.

19. A system as in claim 18, wherein the chamber comprises a free-standing cabinet.

20. A system as in claim 18, wherein a mechanism imparts vibration to the containers, which causes the contents of the container to mix during pH adjustment.

21. A system as in claim 18, further comprising a water bath which receives and humidifies the gas flow.

22. A system as in claim 18, wherein the supports are present on a rotatable carousel present within the chamber.

23. A system as in claim 22, wherein the carousel comprises a plurality of stacked, circular shelves.

24. An inventory of buffer containers comprising:

a plurality of containers filled with an aqueous solution of a sodium bicarbonate solution, wherein each container in the inventory has;

a volume of sodium bicarbonate solution in the range from 1.0 ml to 50.0 ml; and

a pH variation below ±

0.05 when compared to the pH of all other containers in the inventory.

25. An inventory as in claim 24, wherein the sodium bicarbonate solution in each container is maintained at a pressure above atmospheric to inhibit the evolution of carbon dioxide during storage.

26. An inventory as in claim 25, wherein each container has an open interior filled with the sodium bicarbonate solution, a needle-penetrable septum, a plunger, and a compression member which exerts a force on the plunger which is sufficient to pressurize the sodium bicarbonate solution and inhibit the evolution of carbon dioxide.

27. An inventory as in claim 24, further comprising a box which holds the plurality of containers.