Intragastric volume-occupying device and method for fabricating same
Intragastric volume-occupying devices and methods for treating obesity are provided. The devices, which are inflated by carbon dioxide, include an aluminum or silicon oxide barrier layer providing carbon dioxide retention and an alkylene vinyl alcohol polymer layer providing structural integrity in vivo.
1. An intragastric balloon system comprising a composite wall structure configured to maintain a CO 2 leak rate of less than or equal to 40 cc/m 2 /day at 37° C., wherein the composite wall structure comprises:
a supporting film structure having a Young's Modulus of 500 Mpa or greater;
a first CO 2 barrier layer configured such that its CO 2 barrier properties are not substantially affected by exposure to humidity levels within the gastric environment or within a central lumen of the balloon system; and
a second CO 2 barrier layer configured such that its CO 2 barrier properties are not substantially affected by mechanical forces during processing, compacting, or application of external gastric pressures;
wherein the first CO 2 barrier layer comprises a silicon dioxide layer having a thickness of from about 100 Å to about 800 Å and the second CO 2 barrier layer comprises an ethylene vinyl alcohol layer having a thickness of at least about 2 microns.
2. The intragastric balloon system of claim 1 , wherein the supporting film structure comprises a polyethylene terephthalate layer.
3. The intragastric balloon system of claim 2 , wherein the silicon dioxide layer is provided as a coating on one side of the polyethylene terephthalate layer.
4. The intragastric balloon system of claim 3 , wherein the ethylene vinyl alcohol layer is situated between two polyethylene layers, wherein the ethylene vinyl alcohol layer and the two polyethylene layers are bonded together with tie layers, and wherein the silicon dioxide layer is adhesively bonded to one of the polyethylene layers.
5. The intragastric balloon system of claim 1 , wherein the ethylene vinyl alcohol layer is extruded.
6. The intragastric balloon system of claim 5 , wherein the ethylene vinyl alcohol layer is co-extruded with one or more layers of polyethylene.
7. The intragastric balloon system of claim 5 , wherein the ethylene vinyl alcohol layer is sandwiched between two polyethylene layers.
8. The intragastric balloon system of claim 1 , wherein the intragastric balloon system is configured to be swallowable.
9. The intragastric balloon system of claim 1 , wherein the intragastric balloon system is configured to be swallowable and self-inflating.
10. The intragastric balloon system of claim 9 , further comprising a self-sealing valve system attached to the composite wall structure of the balloon system in the central lumen of the balloon system by an adhesive with a shear force greater than about 40 N, the self-sealing valve system comprising a septum, a retaining structure, and a continuous ring, wherein the septum has a durometer that is less than a durometer of the retaining structure, wherein the continuous ring is configured to exert a compressive force on the septum, wherein the balloon system has a weight of less than about 15 g, wherein the balloon system is configured to have a shape upon full inflation selected from the group consisting of ellipsoid, spheroid, and oblate spheroid, and wherein the balloon system is configured to have a volume of from about 90 cm 3 to about 350 cm 3 upon full inflation.
11. The intragastric balloon system of claim 10 , further comprising an inner container within the central lumen of the balloon system, the inner container containing from about 0.28 grams to about 4 grams of an inflation agent, wherein up to about 80 wt. % of a total amount of the inflation agent is powdered citric acid, with a remainder of the inflation agent comprising powdered sodium bicarbonate.