Humidity-management packaging systems and methods
Packaging systems and methods are disclosed for storing a bioprosthetic device comprising a bioprosthetic tissue and maintaining a target relative humidity across a temperature range. The packaging system includes a sealed package defining an internal space having an internal volume, and a humidity control device and bioprosthetic device within the internal space. The humidity control device includes a barrier defining an enclosed space and a humidity control solution comprising glycerol in the enclosed space. At least a portion of the barrier comprises a gas-permeable membrane. The target relative humidity is provided within the internal volume of the sealed package and the control device maintains the target relative humidity across the temperature range by selectively liberating and absorbing water vapor.
1. A packaging system for storing a bioprosthetic device, the packaging system comprising:
a sealed package defining an internal space;
at least one bioprosthetic device disposed within the internal space; and
at least one humidity control device disposed within the internal space, the at least one humidity control device comprising:
an at least partially gas-permeable enclosure defining an enclosed space, and a humidity control solution comprising glycerol, the humidity control solution disposed in the enclosed space defined by the at least partially gas-permeable enclosure;
wherein the at least one humidity control device maintains a relative humidity range about a target relative humidity within the internal space of the sealed package across a temperature range.
2. The packaging system of claim 1 , wherein the sealed package has a water vapor transfer rate of less than about 2 milligrams per day.
3. The packaging system of claim 1 , wherein the at least one humidity control device maintains the relative humidity range within a tolerance of about +−0.10% of the target relative humidity.
4. The packaging system of claim 1 , wherein at least a portion of the at least partially gas-permeable enclosure comprises a gas-permeable membrane.
5. The packaging system of claim 4 , wherein the gas-permeable membrane has a water vapor transfer rate of from about 3 to about 10 mg/cm 2 per 24 hours.
6. The packaging system of claim 4 , wherein:
the gas-permeable membrane has a surface area;
the internal space of the sealed package has an internal volume; and
a ratio of the surface area of the gas-permeable membrane to the internal volume of the internal space of the sealed package is from about 6 to about 30 mg/mL.
7. The packaging system of claim 4 , wherein the gas-permeable membrane has an average porosity of about 8 to about 36 Gurley units.
8. The packaging system of claim 1 , wherein the bioprosthetic device comprises a bioprosthetic tissue that has a reduced water content of about 25% by weight or less.
9. The packaging system of claim 8 , wherein:
the bioprosthetic device is a heart valve; and
the bioprosthetic tissue forms leaflets of the heart valve.
10. A packaging system for storing a bioprosthetic device, the packaging system comprising:
a sealed package defining an internal space; at least one bioprosthetic device disposed within the internal space; and
at least one humidity control device disposed within the internal space, the humidity control device comprising:
an at least partially gas-permeable enclosure defining an enclosed space, and a humidity control solution comprising glycerol, the humidity control solution disposed in the enclosed space defined by the at least partially gas-permeable enclosure.
11. The packaging system of claim 10 , wherein:
the humidity control solution has a total weight;
the internal space of the sealed package has an internal volume; and
a ratio of the total weight of the humidity control solution to the internal volume of the internal space of the sealed package is at least about 6 mg/mL.
12. The packaging system of claim 10 , wherein:
the at least one humidity control device releases water vapor into the internal space when a relative humidity within the internal space decreases due to higher ambient temperatures; and
the at least one humidity control device absorbs water vapor from the internal space when the relative humidity within the internal space increases due to lower ambient temperatures.
13. The packaging system of claim 10 , wherein:
the humidity control solution further comprises an aqueous solution;
the glycerol is provided in a concentration of from about 34% to about 96% (by weight) of the humidity control solution; and
the aqueous solution is provided in a concentration of from about 4% to about 66% (by weight) of the humidity control solution.
14. The packaging system of claim 10 , wherein the at least one humidity control device maintains a target relative humidity within the internal space of the sealed package across a temperature range.
15. The packaging system of claim 14 , wherein the temperature range is from about 18° C. to about 45° C.
16. The packaging system of claim 14 , wherein the target relative humidity is from about 15% to about 95%.
17. The packaging system of claim 14 , wherein a concentration of the glycerol (G W ) (by weight) in the humidity control solution is substantially related to the target relative humidity (RH) according to Eq. 1:
G w =383(−0.189( RH )+19.9) 0.0806 −383 Eq. 1.
18. The packaging system of claim 14 , wherein the target relative humidity (RH) is substantially related to a concentration of the glycerol (G W ) (by weight) in the humidity control solution according to Eq. 2:
RH
=
-
(
G
w
+
383
383
)
12.4
-
19.9
0.189
.
Eq
.
2
19. The packaging system of claim 14 , wherein the at least one humidity control device maintains the target relative humidity within a tolerance of about ±10%.
20. The packaging system of claim 10 , wherein the humidity control solution further comprises a microbicidal agent.
21. The packaging system of claim 20 , wherein the microbicidal agent comprises an aqueous solution comprising about 97% (by volume) water and about 3% (by volume) of a solution of about 0.625% (by weight) glutaraldehyde.
22. A method of storing at least one bioprosthetic device within a packaging system, the method comprising the steps of:
selecting a target relative humidity to be maintained within an outer packaging of the packaging system across a temperature range;
providing at least one humidity control device comprising a humidity control solution, wherein the humidity control solution comprises glycerol and is disposed within an at least partially gas-permeable enclosure; and
sealing the at least one humidity control device and the at least one bioprosthetic device within the outer packaging.
23. The method of claim 22 , wherein selecting the target relative humidity comprises selecting a target relative humidity from about 15% to about 95%.
24. The method of claim 22 , wherein a concentration of the glycerol (G W ) (by weight) in the humidity control solution is substantially related to the target relative humidity (RH) according to Eq. 1:
G w =383(−0.189( RH )+19.9) 0.0806 −383 Eq. 1.
25. The method of claim 22 , wherein the target relative humidity (RH) is substantially related to a concentration of the glycerol (G W ) (by weight) in the humidity control solution according to Eq. 2:
RH
=
-
(
G
w
+
383
383
)
12.4
-
19.9
0.189
.
Eq
.
2
26. The method of claim 22 , wherein:
the humidity control solution has a total weight;
the outer packaging, after sealing, has an internal volume; and
a ratio of the total weight of the humidity control solution to the internal volume of the outer packaging after sealing is at least about 6 mg/mL.
27. The method of claim 22 , wherein the temperature range is from about −18° C. to about 45° C.
28. The packaging system of claim 22 , wherein the at least one humidity control device maintains the target relative humidity within a tolerance of about ±10%.