Osmotic-delivery devices having vapor-permeable coatings

• US 5,798,119 A
• Filed: 06/13/1995
• Issued: 08/25/1998
• Est. Priority Date: 06/13/1995
• Status: Expired due to Fees

• Current Assignee: SC Johnson & Son Incorporated
• Original Assignee: SC Johnson & Son Incorporated
• Inventors: Herbig, Scott M., Miller, Eric J.
• Primary Examiner(s): Page, Thurman K.
• Assistant Examiner(s): Spear, James M.
• Application Number:
  US08/489,888
• Time in Patent Office: 1,169 Days
• Field of Search: 424/473, 424/457, 424/463, 424/468, 424/472, 424/476, 424/480, 424/482, 424/408, 424/409, 604/890.1, 604/892.1
• US Class Current: 424/473
• CPC Class Codes: A61K 9/0004 Osmotic delivery systems; Sustained release driven by osmosis, thermal energy or gas
• CPC Class Codes: B01J 4/04 using osmotic pressure using membranes, porous plates

Abstract

An osmotic device that, following the imbibition water vapor, provides for the controlled release of a beneficial agent to a non-aqueous environment. The device comprises a hydrophilic formulation and a beneficial agent, surrounded by a wall. The wall is formed at least in part of a semipermeable hydrophobic microporous membrane having an average pores size between about 0.1 μm and 30 μm. The pores are substantially filled with a gas phase. The hydrophobic membrane is permeable to water in the vapor phase and the hydrophobic membrane is impermeable to an aqueous medium at a pressure less than about 100 Pa. The beneficial agent is released, for example, by osmotic pumping or osmotic bursting upon imbibition of sufficient water vapor into the hydrophilic formulation. The high water fluxes attendant with these vapor-permeable hydrophobic membranes facilitate the delivery of large quantities of beneficial agents without requiring large surface areas (quantities) of hydrophobic microporous membrane. In addition, use of vapor-permeable hydrophobic microporous membranes allow osmotic devices to be used in environments having limited water availability, such as air or soil.

Claims

1. An osmotic device for the controlled release of a beneficial agent to a non-aqueous environment comprising:

a. a hydrophilic formulation comprising an osmagent;

b. a beneficial agent;

c. a container surrounding the hydrophilic formulation, the beneficial agent, and a water reservoir, said container having at least in part between the water reservoir and the hydrophilic formulation, a semipermeable hydrophobic microporous material having pores that have an average pore size between about 0.1 μ

m and 30 μ

m said pores substantially filled with a gas phase, said hydrophobic material permeable to water in the vapor phase and said hydrophobic material impermeable to liquid water at a pressure less than 100 Pa, said hydrophobic material having a contact angle with water greater than 50 degrees, and said container having at least one opening through which the beneficial agent is released from the device; and

d. a water reservoir in a sealed compartment of the container that when the device is activated, the seal is disrupted allowing water vapor from the reservoir to be available for transport through the semipermeable material.

2. A method for the controlled deliver of a beneficial agent to a non-aqueous environment of use which comprises breaking a seal between a water reservoir and the semipermeable material and placing the device of claim 1 into the environment of use.

3. An osmotic device for the controlled release of a beneficial agent by osmotic pumping to a non-aqueous environment comprising:

a. a hydrophilic formulation comprising an osmagent;

b. a beneficial agent; and

c. a container surrounding the hydrophilic formulation and the beneficial agent, said container at least in part a semipermeable hydrophobic microporous material having pores that have an average pore size between about 0.1 μ

m and 30 μ

m, said pores substantially filled with a gas phase, said hydrophobic material permeable to water in the vapor phase and said hydrophobic material impermeable to liquid water at a pressure less than 100 Pa, said hydrophobic material having a contact angle with water greater than 50 degrees, and said container having at least one opening through which the beneficial agent is released from the device;

wherein the semipermeable hydrophobic membrane has a water vapor transmission rate greater than 2 g-mm/m² -24 hours, a void volume of between 5% and 95%, a thickness of between 5 μ

m and 2 cm, and wherein the semipermeable hydrophobic membrane in the nonporous state is substantially impermeable to the beneficial agent and has an intrinsic permeability to water of less than 1×

10^-7 cm³ (STP)-cm/cm² -sec-cmHg.

4. The osmotic device as recited in claim 3, wherein the hydrophilic formulation has a surface tension of about 60-75 dyn/cm.

5. The osmotic device as recited in claim 4 wherein the osmagent is a sugar.

6. The osmotic device as recited in claim 4 wherein the osmagent is a salt.

7. The osmotic device as recited in claim 4 wherein the hydrophilic formulation includes an aqueous swellable material.

8. The osmotic device as recited in claim 4 wherein said semipermeable hydrophobic material is selected from polyethylene, polypropylene, polyvinyl chloride, polytetrafluoroethylene, polystyrene, polycarbonate, polyethylene-terephthalate, polysulfones, polyacrylonitrile, polyvinylidene chloride, polyamides, polyimides, polyvinylidene fluoride, polyacrylic acid derivatives, natural waxes, or synthetic waxes.

9. The osmotic device as recited in claim 4 wherein said membrane material is polyethylene or polypropylene.

10. The osmotic device as recited in claim 4 wherein the surface area of said membrane material can be increased or decreased to effectively increase or decrease the release rate of beneficial agent.

20. The osmotic device as recited in claim 3 wherein a movable piston component is placed between the hydrophilic formulation and the beneficial agent separating the two components.

22. The osmotic device as recited in claim 20, wherein the hydrophilic formulation has a surface tension of about 60-75 dyn/cm.

23. The osmotic device as recited in claim 22 wherein the osmagent is a sugar.

24. The osmotic device as recited in claim 22 wherein the osmagent is a salt.

25. The osmotic device as recited in claim 22 wherein the hydrophilic formulation includes an aqueous swellable material.

26. The osmotic device as recited in claim 22 wherein said semipermeable hydrophobic material is selected from polyethylene, polypropylene, polyvinyl chloride, polytetrafluoroethylene, polystyrene, polycarbonate, polyethylene-terephthalate, polysulfones, polyacrylonitrile, polyvinylidene chloride, polyamides, polyimides, polyvinylidene fluoride, polyacrylic acid derivatives, natural waxes or synthetic waxes.

27. The osmotic device as recited in claim 22 wherein said membrane material is polyethylene or polypropylene.

28. The osmotic device as recited in claim 22 wherein the surface area of said membrane material can be increased or decreased to effectively increase or decrease the release rate of beneficial agent.

29. The osmotic device as recited in claim 3 wherein a flexible layer is placed between the hydrophilic formulation and the beneficial agent separating the two components.

31. The osmotic device as recited in claim 29, wherein the hydrophilic formulation has a surface tension of about 60-75 dyn/cm.

32. The osmotic device as recited in claim 31 wherein the osmagent is a sugar.

33. The osmotic device as recited in claim 31 wherein the osmagent is a salt.

34. The osmotic device as recited in claim 31 wherein the hydrophilic formulation includes an aqueous swellable material.

35. The osmotic device as recited in claim 31 wherein said semipermeable hydrophobic material is selected from polyethylene, polypropylene, polyvinyl chloride, polytetrafluoroethylene, polystyrene, polycarbonate, polyethylene-terephthalate, polysulfones, polyacrylonitrile, polyvinylidene chloride, polyamides, polyimides, polyvinylidene fluoride, polyacrylic acid derivatives, natural waxes or synthetic waxes.

36. The osmotic device as recited in claim 31 wherein said membrane material is polyethylene or polypropylene.

37. The osmotic device as recited in claim 31 wherein the surface said membrane material can be increased or decreased to effectively increase or decrease the release rate of beneficial agent.

38. The osmotic device as recited in claim 3 wherein said device is in the shape of a flower, bush, fern or other form resembling a plant.

39. The osmotic device as recited in claim 3 wherein the beneficial agent is a fragrance, insecticide, herbicide, fungicide pheromone, or food source.

40. A method for the controlled delivery of a beneficial agent to a nonaqueous environment of use which comprises placing a portion of the device of claim 3 into an aqueous solution.

41. A method for the controlled delivery of a beneficial agent to a nonaqueous environment of use which comprises the device of claim 3 such that the hydrophobic microporous material is exposed to humid air.

11. An osmotic device for the controlled release of a beneficial agent by osmotic bursting to a non-aqueous environment comprising:

a. a hydrophilic formulation comprising an osmagent;

b. a beneficial agent; and

c. a container surrounding the hydrophilic formulation and the beneficial agent, said container at least in part a semipermeable hydrophobic microporous material having pores that have an average pore size between about 0.1 μ

m and 30 μ

m, said pores substantially filled with a gas phase, said hydrophobic material permeable to water in the vapor phase and said hydrophobic material impermeable to liquid water at a pressure less than 100 Pa, said hydrophobic material having a contact angle with water greater than 50 degrees, and said container having at least one opening through which the beneficial agent is released from the device;

wherein the semipermeable hydrophobic membrane has a water vapor transmission rate greater than 2 g-mm/m² -24 hours, a void volume of between 5% and 95%, a thickness of between 5 μ

m and 2 cm, and wherein the semipermeable hydrophobic membrane in the nonporous state is substantially impermeable to the beneficial agent and has an intrinsic permeability to water of less than 1×

10^-7 cm³ (STP)-cm/cm² -sec-cmHg.

12. The osmotic device as recited in claim 11 wherein said device is in the shape of a flower, bush, fern or other form resembling a plant.

13. The osmotic device as recited in claim 11, wherein the hydrophilic formulation has a surface tension of about 60-75 dyn/cm.

14. The osmotic device as recited in claim 13 wherein the osmagent is a sugar.

15. The osmotic device as recited in claim 13 wherein the osmagent is a salt.

16. The osmotic device as recited in claim 13 wherein the hydrophilic formulation includes an aqueous swellable material.

17. The osmotic device as recited in claim 13 wherein said semipermeable hydrophobic material is selected from polyethylene, polypropylene, polyvinyl chloride, polytetrafluoroethylene, polystyrene, polycarbonate, polyethylene-terephthalate, polysulfones, polyacrylonitrile, polyvinylidene chloride, polyamides, polyimides, polyvinylidene fluoride, polyacrylic acid derivatives, natural waxes or synthetic waxes.

18. The osmotic device as recited in claim 13 wherein said membrane material is polyethylene or polypropylene.

19. The osmotic device as recited in claim 13 wherein a the surface area of said membrane material can be increased or decreased to effectively increase or decrease the release rate of beneficial agent.

21. The osmotic device as recited claim 11 wherein the beneficial agent is a fragrance, insecticide, herbicide, fungicide, pheromone, or food source.

30. A method for the controlled delivery of a beneficial agent to a nonaqueous environment of use which comprises placing a portion of the device of claim 11 into an aqueous solution.

42. A method for the controlled delivery of a beneficial agent to a nonaqueous environment of use which comprises the device of claim 11 such that the hydrophobic microporous material is exposed to humid air.