# US 11,432,959 B2 · Porous structures for extended release drug delivery devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,432,959 B2 - Document ID: US11432959B2 - Status: Granted - Kind: B2 - Application number: 15/777,593 - Filed: 2016-11-18 - Published: 2021-07-08 - Granted: 2022-09-06 - Earliest claimed: 2015-11-20 - Assignees: ForSight Vision4, Inc. - Applicants: ForSight Vision4, Inc. - Inventors: Randolph E. Campbell; Kevin W. Sacherman; Kathleen Cogan Farinas; Signe Erickson; Jeremy Boyette - Web page: https://patentgrep.com/patent/US11432959B2 ## CPC - A61F 9/0017: {implantable in, or in contact with, the eye, e.g. ocular inserts} - A61F 9/0026: {Ophthalmic product dispenser attachments to facilitate positioning near the eye} - A61M 31/002: {Devices for releasing a drug at a continuous and controlled rate for a prolonged period of time (artificial gland structures or devices A61F2/022; intra-uterine contraceptive devices A61F6/14; tampons for introducing into the vagina A61F13/20, A61L15/00; suppositories or bougies for intra-vaginal or intra-uterine application A61K9/02; physical forms of medicinal preparations for sustained or differential drug release A61K9/20, A61K9/50)} - A61P 27/02: Ophthalmic agents - A61F 2250/0067: Means for introducing or releasing pharmaceutical products into the body - A61F 2250/0068: the pharmaceutical product being in a reservoir - A61M 5/14276: {specially adapted for implantation} - A61M 37/00: Other apparatus for introducing media into the body (for reproduction or fertilisation A61B17/425; apparatus for iontophoresis or cataphoresis A61N1/30); Percutany, i.e. introducing medicines into the body by diffusion through the skin (salt baths A61H33/04) - A61M 2205/02: characterised by a particular materials - A61M 2205/04: implanted - A61M 2205/125: with incorporated filters - A61M 2205/75: with filters - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} - A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS ## Abstract A therapeutic device for extended release drug delivery including a refillable reservoir configured to receive a therapeutic agent and having an outlet for delivery of the therapeutic agent to a patient from the reservoir over an extended period. A porous structure is coupled near the outlet of the reservoir, the porous structure formed of sintered material. A barrier layer is coupled to the reservoir on or adjacent a surface of the porous structure such that the therapeutic agent passes through both the porous structure and the barrier layer upon delivery from the reservoir through the outlet. The porous structure is tuned to deliver the therapeutic agent at a diffusion rate and the barrier layer is adapted to block passage of particles having an average particle size within an average particle size range that is outside an average particle size range blocked by the porous structure. Related methods and systems are provided. ## Claims ### Claim 1 A therapeutic device for extended release drug delivery, the device comprising: a refillable reservoir configured to receive a therapeutic agent and having an outlet for delivery of the therapeutic agent to a patient from the reservoir over an extended period, wherein the reservoir is configured to be refillable via a proximal access portion opening of the device while the device is implanted in the patient; a porous structure coupled near the outlet of the reservoir, the porous structure formed of sintered material; and a barrier layer coupled to the reservoir on or adjacent a surface of the porous structure such that the therapeutic agent passes through both the porous structure and the barrier layer upon delivery from the reservoir through the outlet, wherein the surface of the porous structure is an inner-facing surface of the porous structure, the inner-facing surface facing the reservoir; wherein the porous structure is tuned to deliver the therapeutic agent at a diffusion rate, and wherein the porous structure has a first mean pore size and the barrier layer has a second mean pore size that is smaller than the first mean pore size so the barrier layer blocks particles having an average particle size range that is different from or outside an average particle size range blocked by the porous structure; and wherein the diffusion rate is controlled by the porous structure so the diffusion rate of the therapeutic agent through the porous structure is unchanged by the presence of the barrier layer. ### Claim 2 (depends on 1) The therapeutic device of claim 1, wherein the average particle size range blocked by the barrier layer is greater than 0.01 um. ### Claim 3 (depends on 1) The therapeutic device of claim 1, wherein the average particle size range blocked by the barrier layer is greater than 1 nm. ### Claim 4 (depends on 1) The therapeutic device of claim 1, wherein the porous structure has a mean pore size that is between 3 microns to 50 microns and the barrier layer has a mean pore size that is between 0.01 microns to 0.1 microns. ### Claim 5 (depends on 1) The therapeutic device of claim 1, wherein the barrier layer coupled within the reservoir is spaced a distance proximal to the inner-facing surface of the porous structure. ### Claim 6 (depends on 1) The therapeutic device of claim 1, wherein the barrier layer is a filter membrane formed of a material selected from the group consisting of silver metal, cellulose acetate, ceramic, glass fiber, borosilicate fiber, mixed cellulose ester (MCE), nylon, polyacrylonitrile (PAN), polycarbonate track etch (PCTE), polyethersulfone (PES), polyester track etch (PETE), polypropylene (PP), polytetra fluoroethylene (PTFE), and polyvinylidene fluoride (PVDF). ### Claim 7 (depends on 1) The therapeutic device of claim 1, wherein the sintered material is stainless steel or titanium. ### Claim 8 (depends on 1) The therapeutic device of claim 1, wherein the second mean pore size is effective to block passage of the particles having the average particle size within the average particle size range blocked by the barrier layer, wherein the average particle size range blocked by the barrier layer is equal to or greater than 0.2 microns and greater than an average particle size range of the therapeutic agent. ### Claim 9 (depends on 1) The therapeutic device of claim 1, wherein the particles blocked by the barrier layer comprises one or more microbes, bacteria, fungal spores, immune cells, or antibodies. ### Claim 10 (depends on 1) The therapeutic device of claim 1, wherein the porous structure has a first porosity and the barrier layer has a second porosity, wherein the first porosity is higher than the second porosity, wherein the first porosity is from 16% to 30% and the second porosity is from 1% to 15%. ### Claim 11 (depends on 1) The therapeutic device of claim 1, wherein the porous structure has a thickness from 70 microns to 5000 microns and the barrier layer has a thickness from 10 nm to 150 microns. ### Claim 12 (depends on 1) The therapeutic device of claim 1, wherein the barrier layer mitigates a bolus release of the therapeutic agent through the porous structure upon an increase in pressure within the reservoir. ### Claim 13 (depends on 1) The therapeutic device of claim 1, wherein the barrier layer has a thickness that is significantly less than a thickness of the porous structure, so as to maintain effectively the same thickness of the porous structure alone whether the barrier layer is a coating deposited on the surface of the porous structure or a discrete structure in series with the porous structure.