Punctal implants with controlled drug delivery features and methods of using same
Disclosed herein are drug delivery punctal implants and methods of using the implants for the treatment of ocular disorders requiring targeted and controlled administration of a drug to an interior portion of the eye for reduction or prevention of symptoms of the disorder. The physical arrangement of drugs within the punctal plugs disclosed herein results, in several embodiments, in advantageous controlled delivery of one or more drugs to the eye of a patient.
1. A punctal implant for insertion into a punctum of the eye of a subject and configured to deliver two or more drugs to the eye of the subject, the implant comprising:
an outer shell comprising (i) a proximal end comprising at least one region of drug release and an asymmetrical flange, (ii) a closed distal end, and (iii) an interior lumen comprising at least two drugs positioned within the lumen,
wherein the region of drug release comprises an occlusive member that is permeable to said two or more drugs, the occlusive member positioned at least partially within the interior lumen,
wherein said occlusive member allows elution of the two or more drugs to occur only through the occlusive member,
wherein the thickness of the occlusive member at least partially defines the elution rate of the two or more drugs,
wherein the asymmetrical flange has a length extending in a first direction that exceeds a width extending in a second direction and is configured to rest on the surface of the eyelid when the implant is inserted into the punctum,
wherein the first and second drug elute from the lumen to the tear film of the eye of the subject by passing through the at least one region of drug release, and
wherein the first drug is a discontinuous first phase dispersed within the second drug.
2. The implant of claim 1 , wherein the occlusive member is dimensioned based on the permeability of said occlusive member to said first and second drugs and the desired relative timing and duration of elution of said first and second drugs.
3. The implant of claim 1 , wherein the occlusive member is integrally formed with the outer shell of the implant.
4. The implant of claim 1 , wherein the occlusive member further comprises randomly or patterned holes through the occlusive member.
5. The implant of claim 1 , wherein the first drug is placed in a more proximal position within the interior lumen relative to the position of the second drug.
6. The implant of claim 1 , wherein the second drug provides an environment that improves the stability of the first drug.
7. A punctal implant for insertion into a punctum of the eye of a subject and configured to deliver two or more drugs to the eye of the subject, the implant comprising:
an outer shell comprising (i) a proximal end comprising at least one region of drug release and an asymmetrical flange, (ii) a closed distal end, (iii) an interior lumen comprising at least two drugs positioned within the lumen,
wherein the region of drug release comprises an annular ring component comprising a material that is permeable or semi-permeable to at least one of the two or more drugs, the annular ring component defining an aperture, wherein the annular ring component is positioned at the proximal-most portion of the interior lumen and entirely within the interior lumen,
wherein said aperture allows elution of the two or more drugs to occur through the annular ring component,
wherein the dimensions of the aperture at least partially define the elution rate of the two or more drugs,
wherein the diameter of the aperture is smaller than a diameter of the interior lumen,
wherein the asymmetrical flange has a length extending in a first direction that exceeds a width extending in a second direction and is configured to rest on the surface of the eyelid when the implant is inserted into the punctum, and
wherein the first and second drug elute from the lumen to the tear film of the eye of the subject by passing through the at least one region of drug release.
8. The implant of claim 7 , wherein the outer shell comprises a radial bulge in a distal region in order to anchor the implant in the punctum.
9. An implant according to claim 7 , wherein the first drug elutes for a period of between 1 and 75 days, and second drug elutes for a period of time ranging from about 1 to about 24 months after the first drug is eluted.
10. An implant according to claim 7 , wherein the implant has a length of between about 0.5 and about 2.5 mm.
11. An implant according to claim 7 , wherein the implant has a diameter of about 0.2 to about 1.5 mm.
12. An implant according to claim 7 , wherein the first drug is a steroid.
13. The implant of claim 12 , wherein the steroid is selected from the group consisting of loteprednol etabonate, dexamethasone, and triamcinolone acetonide.
14. An implant according to claim 7 , wherein the second drug is cyclosporine and is optionally formulated as a nanodispersion.
15. An implant according to claim 7 , wherein the first drug facilitates tear production.
16. The punctal implant of claim 1 , wherein the occlusive member comprises two or more holes.
17. The punctal implant of claim 1 , wherein the closed distal end comprises a plug.