Ophthalmic device with a shielding material to protect against degradation during active drug release

Abstract

An ophthalmic device can be configured for active drug delivery. The ophthalmic device can include a body; a reservoir positioned within the body and configured to store at least one drug; and a metal cap configured to cover an opening of the reservoir. The metal cap can be dissolved by application of an electrical signal, which can actively release the at least one drug from the reservoir upon receipt of an electrical signal and create reaction products. At least one of the electrical signal and the reaction products may cause degradation of the at least one drug. Water from the eye can also cause problems with degradation. Accordingly, a shielding material can be utilized as a barrier or defender to protect the drug from degradation due to the active release.

Description

[0001] OPHTHALMIC DEVICE WITH A SHIELDING MATERIAL TO PROTECT AGAINST DEGRADATION DURING ACTIVE DRUG RELEASE

[0002] CROSS-REFERENCE TO RELATED APPLICATION

[0003] The present application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 547,207, filed November 3, 2023, which is incorporated by reference herein in its entirety.

[0004] Technical Field

[0005] The present disclosure relates generally to active drug delivery from an ophthalmic device, and more specifically, to using a shielding material within an ophthalmic device to protect at least one drug and / or a wearer’ s eye from degradation as the at least one drug is actively released for delivery to the wearer’s eye.

[0006] Background

[0007] Ophthalmic devices are increasingly used for a variety of therapeutic purposes. Such ophthalmic devices can be configured to actively release at least one drug from a covered storage reservoir to a patient’s eye. The covering of the storage reservoir can be, for example, a cap. Often, the cap is made of gold, which can electrodissolve in response to application of an electrical signal. The at least one drug stored in the reservoir can be released as the cap is electrodissolved. However, the process of the active release can degrade the at least one drug. For example, the electrical signal and the products of the electrochemical reaction can cause the at least one drug to degrade, potentially leading to irritation and / or loss of therapeutic efficacy of the at least one drug.

[0008] Summary

[0009] The present disclosure describes using a shielding material within an ophthalmic device to protect at least one drug and / or a wearer’s eye from degradation (e.g., due to harmful reaction products, application of an electrical signal, water from the eye, or the like) as the at least one drug is actively released for delivery to the wearer’s eye. In an aspect, the present disclosure includes an ophthalmic device that can include a body; a reservoir positioned within the body and configured to store at least one drug; and a metal cap configured to cover an opening of the reservoir. The metal cap can dissolve (e.g., upon receiving an electrical signal) to release the at least one drug from the reservoir. The metal cap can dissolve into at least one reaction product. A shielding material can be configured to protect the drug from degradation (e.g., due to the at least one reaction product, the electrical signal, and / or water from an eye) when the metal cap dissolves.

[0010] In another aspect, the present disclosure includes a system for release of at least one drug from an ophthalmic device. A signal generator can be configured to generate an electrical signal. At least one reservoir can be positioned within a body of the ophthalmic device. Each of the at least one reservoir can be configured to store at least one drug and configured to have an opening covered by a metal cap. The metal cap can be configured to, in response to receiving an electrical signal from the signal generator, undergo an electrochemical reaction and dissolve to release the at least one drug from the reservoir. The metal cap can dissolve into at least one reaction product. A shielding material can be used to protect the at least one drug in the at least one reservoir from degradation (e.g., due to the at least one reaction product, the electrical signal, and / or water from an eye) when the metal cap dissolves.

[0011] In a further aspect, the present disclosure includes a method for delivering at least one drug to a patient’s eye from an ophthalmic device. An electrical signal to metal cap can be applied to the metal cap to dissolve the metal cap via electrochemical reaction. The at least one drug can be shielded from degradation (e.g., due to the at least one reaction product, the electrical signal, and / or water from an eye) when the metal cap dissolves. The metal cap can be dissolved to remove the metal covering the reservoir in response to the electrical signal but can also produce electrochemical reaction products. The at least one drag can be temporarily blocked to protect the drug from degradation (e.g., due to the at least one reaction product, the electrical signal, and / or water from the eye) by a shielding material and subsequently released from the reservoir. The present disclosure also includes methods for making the ophthalmic device that incorporates the shielding material to protect at least one drag from degradation (e.g., due to the at least one reaction product, the electrical signal, and / or water from an eye) when the metal cap dissolves. Brief Description of the Drawings

[0012] The foregoing and other features of the present disclosure will become apparent to those skilled in the art to which the present disclosure relates upon reading the following description with reference to the accompanying drawings, in which:

[0013] FIG. 1 shows a diagram of the time course of traditional active drug release according to the prior art;

[0014] FIG. 2 shows a diagram of the time course of active drug release using a shielding material;

[0015] FIG. 3 shows a diagram of a system that can at least partially shield at least one drug from degradation within an ophthalmic device due to active release of the at least one drug from the ophthalmic device;

[0016] FIG. 4 shows a diagram of an example of the system of FIG. 3 in operation;

[0017] FIGS. 5-8 show diagrams of different examples of the system of FIG. 4 in operation with different placements of the shielding material; and

[0018] FIG. 9 shows a process flow diagram illustrating a method for protecting one or more drugs from degradation within an ophthalmic device due to active release of at least one drug from the ophthalmic device.

[0019] Detailed Description

[0020] I. Definitions

[0021] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the ail to which the present disclosure pertains.

[0022] As used herein, the singular forms “a,” “an” and “the” can also include the plural forms, unless the context clearly indicates otherwise. As used herein, the terms “comprises” and / or “comprising,” can specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups.

[0023] As used herein, the term “and / or” can include any and all combinations of one or more of the associated listed items.

[0024] As used herein, the terms “first,” “second,” etc. should not limit the elements being described by these terms. These terms are only used to distinguish one element from another. Thus, a “first” element discussed below could also be termed a “second” element without departing from the teachings of the present disclosure. The sequence of operations (or acts / steps) is not limited to the order presented in the claims or figures unless specifically indicated otherwise.

[0025] As used herein, the term “ophthalmic device” refers to a medical instrument used on and / or within a portion of a patient’s eye for optometry or ophthalmology purposes (e.g., for diagnosis, surgery, vision correction, or the like). An ophthalmic device can be “smart” when it includes one or more components that facilitate one or more active processes for purposes other than traditional lens-based vision correction (e.g., active drug release from the ophthalmic device).

[0026] As used herein, the term, “shielding material” refers to one or more solid components that can act as a barrier and / or defender (e.g., layer and / or dispersant) within an ophthalmic device to protect at least one drug and / or eye of a wearer of the ophthalmic device from degradation due to the active release of the at least one drug from the reservoir (e.g., the degradation may be due to harmful reaction products, application of an electrical signal, water from the eye, or the like). One or more types of shielding material can be used within a single ophthalmic device.

[0027] As used herein, the term “drug”, which can also be referred to as a “therapeutic agent”, “medication”, or the like, refers to one or more substances (e.g., liquid, solid, or gas) that is a pharmaceutical and / or a non-pharmaceutical related to the treatment, symptom relief, and / or palliative care of a disease, injury, or other malady. Any of the drugs described herein may be stored in a liquid, solid, or gaseous state. As used herein, the term “reservoir” refers to a storehouse for at least one drug. A reservoir can include an internal volume to hold the at least one drug and can have an opening that is covered until the covering is actively removed to release of the one or more drugs from the reservoir (e.g., allowing for diffusion of the drug out of the reservoir and into the surrounding body of the ophthalmic device and to the eye).

[0028] As used herein, the term “cap” refers to a substance that covers an opening of a reservoir such that when present, at least one drug is confined in the reservoir by the cap, and when no longer present, the ding can be released from the reservoir. At least a portion of the cap can be an electrode (e.g., a working electrode) that can be dissolved (e.g., electro dissolved) to facilitate the release of the drug. As an example, the electrode can be a metal electrode, such as a gold electrode, which may be embodied as a thin metal film.

[0029] As used herein, the term “electrode” refers to a conductive solid (e.g., including one or more metals, one or more polymers, or the like) that receives / transmits an electrical signal. Unless otherwise noted, the term “metal electrode” is used to refer to the “working electrode” of an electrochemical system, which includes the working electrode, a counter electrode, and a reference electrode.

[0030] As used herein, the term “working electrode” refers to an electrode (e.g., a metal electrode) on which a reaction of interest (e.g., electrodissolution) is occurring. A non-limiting example of the working electrode is a gold electrode, such as a thin-film gold electrode. In some instances, the working electrode can be at least a portion of the cap.

[0031] As used herein, the term “reference electrode” refers to an electrode that has a constant electrochemical potential as long as no current flows through it.

[0032] As used herein, the term “counter electrode” refers to an electrode that completes the circuit and applies an input potential.

[0033] As used herein, the term “active” when referring to drag release from an ophthalmic device refers to a drag delivery that is governed by an electrical signal that actuates the release of the drug from the reservoir. Active contrasts with a passive or eluting only forms of drug release. As used herein, the term “hydrogel” refers to a crosslinked hydrophilic polymer that does not dissolve in water. A hydrogel is generally highly absorbent yet maintains a well-defined structure.

[0034] As used herein, the terms “user”, “subject”, and “patient” can be used interchangeably and refer to any warm-blooded organism including, but not limited to, a human being, a pig, a rat, a mouse, a dog, a cat, a goat, a sheep, a horse, a monkey, an ape, a rabbit, a cow, etc.

[0035] II. Overview

[0036] Ophthalmic devices can be used to actively release at least one drug to an eye of a user. One example of an active release ophthalmic device stores the at least one drug in a reservoir, or a number of reservoirs, each reservoir having an opening that is covered by a metal cap. By applying an electrical signal to the metal cap, the metal cap can dissolve to open the reservoir to release the at least one drug into the body of the ophthalmic device and toward the eye. However, the at least one drug can be degraded (or otherwise damaged) by products related to the dissolving cap (e.g., an electrical signal, an electrochemical reaction product, water, etc.), potentially leading to irritation of the eye and / or loss of therapeutic efficacy of the at least one drug.

[0037] The present disclosure described systems, and methods of making and using those systems, that can protect the at least one drug from degradation and the eye from irritants like those described above. The systems can include a shielding material in the body of the ophthalmic device and / or in each of the reservoirs of the ophthalmic device. The shielding material can be a material that can insulate the at least one drug for the time of the electrical signal application, the electrochemical reaction, until the electrochemical reaction products dissipate. The shielding material can then allow the drug to be released from the reservoir and / or the ophthalmic device out of the eye. The shielding material can also and / or alternatively, be a material that can interact with the reaction products to render the reaction products harmless (or less harmful) to the at least one drug and / or the eye. Thus, the addition of certain shielding materials selectively positioned within the ophthalmic device can protect the at least one drug from degradation and the eye from irritants. III. Systems

[0038] An active drug dispensing ophthalmic device, such as a smart contact lens, can release at least one drug from at least one reservoir to an eye of a wearer in response to an input. The reservoir can hold one or more drugs and at least a portion of the reservoir can be covered by a cap to enclose to one or more drugs in the reservoir. The input can be an electrical signal that can instruct cap to dissolve. Each ophthalmic device can include one or more reservoirs / caps that can be addressed (activated) separately and / or in any combination. Unless otherwise noted, a single reservoir storing one or more drugs therein will be described, but it should be understood that the description also applies to multiple reservoir embodiments.

[0039] As shown in FIGS. 1 and 2, a trigger for the active release of the at least one drug stored in the at least one reservoir can be started at a time (START). The trigger can be started in response to an input such as a preprogramed time, a manual input, a closed loop command based on a sensor recording, or the like. For example, the trigger can be an electrical signal with a voltage (e.g., sent from a signal generator (not shown) to a metal cap covering a reservoir) that causes dissolution of the metal cap covering the reservoir storing the one or more drug(s). As shown in FIGS. 1 and 2, the trigger can activate metal cap dissolution immediately upon starting.

[0040] As shown in timeline 10 in prior ait FIG. 1, generally at some time after the metal cap dissolution starts (e.g., after a time necessary for enough of a portion of the metal cap to dissolve) the drug release can start, but so can electrochemical degradation (e.g., of the drug) and reaction product(s) based degradation. For example, the sources of these electrochemical and reaction product(s) based degradation can include the electrical signal trigger (from a signal generator, not illustrated, and can last until the electrical signal trigger ENDs), one or more reaction product(s) released by the dissolution of the metal cap , and / or water (e.g., tears from the eye). The degradation sources can cause degradation and / or damage to the at least one drug and / or irritation of the eye. In some instances, the degradation can reduce the efficacy of the drug being released, reduce the amount of the effective drug the reaches the eye, cause damage to the ophthalmic device itself, and / or irritation to the eye if harmful products are eluted out of the ophthalmic device. The method of traditional active drug release depicted in the timeline 10 of FIG. 1 can be considered as defining a one-step method as the drag release begins upon the dissolution of the metal cap. In contrast, the timeline 20 in FIG. 2 shows a method for active release of a drug that can use one or more shielding materials to protect against effects from, stop, reduce, and / or remove causes of degradation. With the addition of one or more shielding materials in the ophthalmic device, the active drug release from the ophthalmic device may be considered a two-step or time delayed method that includes (1) dissolving the metal cap and (2) releasing the one or more drug(s) after the shielding material has insulated / inactivated / neutralized / etc. at least a portion of the degradation source(s), or their effects. The shielding can, generally, separate the activation phase (metal cap dissolution) from the release phase (drug release). The drug release is still based on an active process and kinetics of the drug release do not change; instead, the drug release is simply delayed by the one or more shielding materials allowing the products from dissolving the metal cap to clear before releasing the one or more drugs. The shielding by the one or more shielding materials can at least substantially halt and / or slow loss of therapeutic efficacy of the one or more drugs due to degradation / damage of the at least one drug and / or irritation of the eye. As an example, during shielding the shielding material protects the one or more drugs from the electrochemical reaction of the metal cap dissolution, only allowing the one or more drugs to be released after the degradation source(s) have been absorbed, interacted with, and / or dispersed by the shielding material.

[0041] FIG 3 shows a simplified diagram of an ophthalmic device 30 having a body 12. One or more drug(s) 14 can be stored within at least one reservoir (not shown in FIG. 3) in the body 12 of the ophthalmic device 30. The at least one reservoir and / or the body 12 of the ophthalmic device 30 can also include at least one shielding material 16 that can be configured and positioned to at least partially protect the one or more drug(s) 14 from degradation source(s) 18 (at least partially — e.g., greater than or equal to 50% of the drug(s) 14, greater than or equal to 60% of the drug(s) 14, greater than or equal to 70% of the drug(s) 14, greater than or equal to

[0042] 80% of the drug(s) 14, greater than or equal to 85% of the drug(s) 14, greater than or equal to

[0043] 90% of the drug(s) 14, greater than or equal to 95% of the drug(s) 14, greater than or equal to

[0044] 97% of the drug(s) 14, greater than or equal to 98% of the drug(s) 14, greater than or equal to

[0045] 99% of the drug(s) 14, 100% of the drug(s) 14, etc.). The degradation source(s) 18 can be provided / induced directly or indirectly due to the mechanics of the active release. The degradation source(s) 18 can be, for example, an electrical signal triggering active release, a reaction product of an electrochemical reaction formed by the active release, water from the eye, or the like. Notably, the shielding material 16 can at least partially block (as illustrated, repel) the degradation sourcc(s) from reaching the drug(s) for a time period (e.g., the time period when the degradation source(s) are active.

[0046] FIG. 4 shows an example diagram of an ophthalmic device 40 that is a contact lens. While the ophthalmic device 40 is illustrated as a contact lens in FIG. 4 (and an example contact lens is similarly shown in FIGS. 5-8), this example is only for ease of illustration and is not meant to be limiting. Elements (A) and (B) of FIG. 4 show the ophthalmic device 40 at different time points. The ophthalmic device 40 includes body 12 encapsulating a reservoir 26 configured to hold one or more drug(s) 14 and having a metal cap 28 covering an opening of the reservoir. The ophthalmic device 40 further includes shielding material 16 (examples shown as shields 1 and 2) positioned in the body 12 of the ophthalmic device and / or inside the reservoir 26. Element (A) shows the ophthalmic device 40 at a time the active release is being triggered (at time Tl), e.g., the electrical signal is being sent from signal generator 22 to the metal cap 28 to begin dissolution of the metal cap. It should be understood that in this example, the dissolution is electrodissolution. Element (B) shows the ophthalmic device 40 (at time T2) after the dissolution of the metal cap 28 into example degradation source(s) 18 when the shielding material 16 is acting to protect (shown as blocking) the degradation source(s) from interacting with the one or more drug(s) 14. It should be understood that ophthalmic device 40 is a cartoon generally showing what happens within ophthalmic device 40 and is not meant to show an exact type of degradation protection. Specific examples are shown in FIGS. 5-8. Additionally, although a single reservoir 26 and metal cap 28 pair is shown in FIG. 4, as well as FIGS. 5-8, it should be understood that this is only for ease of illustration and is not meant to be limiting; in fact, two or more reservoir 26 and metal cap 28 pairs can be within the body 12 of the ophthalmic device 40 including the same one or more drug(s) 14 or different one or more drug(s) 14. For example, different reservoirs can include different or the same drugs that can have timed and / or controlled releases throughout a given time cycle (e.g., an hour, a day, a week, a month, etc.).

[0047] The ophthalmic device 40 can include a body 12 that can be made of a hydrogel matrix formed of a hydrogel-based material and water. The hydrogel-based material can be any crosslinked hydrophilic polymer that does not dissolve in water. Accordingly, the hydrogel-based material can be stiff when dry, but soft and pliable when hydrated. The hydrogel-based material is highly absorbent and has a naturally-high water content (e.g., 20 % - 60 %), yet maintains a well-defined structure. Non-limiting examples of hydrogel-based material monomers are hydroxy ethyl methacrylate (HEM A) or derivatives, methacrylic acid (MA) or derivatives, methyl methacrylate (MMA) or derivatives, n-vinyl perrolidone (NVP) or derivatives, poly vinyl alcohol (PVA) or derivatives, polyvinyl pyrrolidone (PVP) or derivatives, and the like. In some instances, the hydrogel-based material can include silicone (as a “silicone-hydrogel”), increasing the oxygen transmissibility and permeability of the hydrogel (among other bulk and surface properties that the presence of silicone improves).

[0048] The reservoir 26 can be positioned within the body 12 and can store the one or more drug(s) 14. The one or more drug(s) 14 are shown as one type of drug with multiple molecules, represented as circles, in the drawings of FIG. 4 (and similarly in FIGS. 5-8), but it should be understood that two or more drugs can be stored in a single reservoir 26. The reservoir 26 can have an opening that is covered by a metal cap 28, which in some instances can be a thin film of metal. As an example, a thin film metal cap 28 can be a gold thin film electrode including gold or a gold alloy. The metal cap 28 can be dissolvable to release the one or more drug(s) 14 from the reservoir 26 (e.g., based on a time, a manual input, a sensor reading using a closed loop control, or the like). The metal cap can dissolve into at least one degradation source 18 (e.g., a reaction product).

[0049] For example, the metal cap 28 can be dissolved (e.g., electrodissolved) in response to receiving an electrical signal from a signal generator 22 (which can be any device or combination of devices configured to generate the electrical signal). The electrical signal sent from the signal generator 22 can have a voltage appropriate to dissolve the metal cap 28. Other components, such as circuitry, can connect the signal generator 22 (not shown) to the metal cap 28. It should be understood that the electrical signal can be received by one or more components of the ophthalmic device 40 (alterative or additional to the metal cap 28) and the electrical signal can be generated / transmitted by any circuitry or device related to the signal generator 22. The signal generator 22 can be internal to the ophthalmic device 40, such as encapsulated within the body 12, and / or external to the ophthalmic device 40. For instance, when the signal generator is internal to the ophthalmic device, the signal generator can be positioned anywhere within the body 12 as long as the signal generator is electrically connected at least to the metal cap 28.

[0050] When the metal cap 28 is electrodissolved, electrochemical reaction products (otherwise called "reaction products”) such as reactive ionic species can be produced. Such reaction products are one example of degradation source(s) 18. Other examples of degradation source(s) 18 can include, but are not limited to, the electrical signal applied to electrodissolve the metal cap 28 and water (from tears of the eye). One or more of the degradation source(s) 18 can cause degradation / damage of the one or more drug(s) 14 (e.g., that reduces the effectiveness of the drug and / or the amount of effective drug that can reach the eye), degradation / damage to one or more components of the ophthalmic device 40, and / or irritation of the eye. The ophthalmic device 40 can include one or more shielding materials 16 (example shields 1 and 2 shown in FIG. 4) positioned within the body 12 of the ophthalmic device and / or within the reservoir 26. The shielding material(s) 16 can protect the one or more drug(s) 14 from degradation when the metal cap 28 begins to dissolve. The shielding material(s) 16 can also, and / or alternatively, protect the eye from irritation and / or one or more other components inside the ophthalmic device 40 from damage. The shielding material(s) 16 can be a barrier layer in the reservoir 26 between the metal cap 28 and the one or more drug(s) 14 and / or dispersed in at least one portion of the body 12 of the ophthalmic device 40. If more than one shielding material 16 is used, then the shielding material(s) can be the same material and / or different materials. For example, a first shielding material (shield 1) can be a metal material dispersed within at least a portion of the body 12 and a second shielding material (shield 2) can be a polymer barrier layer positioned in the reservoir 26 between the metal cap 28 and the one or more drug(s) 14.

[0051] The one or more shielding material(s) 16 can protect from degradation due to the one or more degradation source(s) 18, such as, the at least one reaction product, the electrical signal, and / or water from the eye. For instance, the electrical signal can have a voltage necessary to electrodissolve the metal cap 28, but the voltage necessary to electrodissolve the metal cap can be disruptive itself. If the one or more drug(s) 14 are in contact with the metal cap 28 when the electrical signal is received by the metal cap, then the electrical signal can be conducted to the drug and can degrade the one or more drugs. Additionally, if water from tears of the eye diffused into the body 12 of the ophthalmic device 40 enters the reservoir 26 through a partially dissolved metal cap 28 while the electrical signal i still being received by the metal cap, then the electrical signal can be conducted to the one or more drug(s) 14 through water and can degrade the one or more drugs. In another instance, water from the tears of the eye may degrade certain drugs (e.g., if interacts with the one or more drug(s) 14 too soon, if too much water dilutes the one or more drug(s). etc.). Additionally, moisture ingress into the drag reservoir may dissociate a portion of a solid state drag into an aqueous state more apt to react in an electrochemical reaction. As another example, the electrochemical reaction products formed by the electrodissolution of the metal cap 28 can be harmful to the one or more drug(s) 14, one or more components of the ophthalmic device 40, and / or the eye.

[0052] The following are several examples based on the metal cap being made of gold (e.g., a gold thin film). In one instance, timolol, a common drag for treatment of glaucoma, oxidizes at +1.0 V vs. Ag / AgCl. If the metal cap 28 is a thin film gold cap, then the gold cap can begin a dissolution reaction around +1.2 V vs. Ag / AgCl, leading to a risk of drug degradation from the electrical signal needed to dissolve the gold cap. In another instance, irreversible oxidation of brimonidine, another drug for treatment of glaucoma, can occur at +.36 V and + 1.25 V, If the metal cap 28 is a thin film gold cap, then there can be a risk of drug degradation from the electrical signal as well. In another example when the metal cap 28 is gold, the electrodissolution of the gold can produce reactions products such as tetrachloro aurate ions. Tetrachloroaurate ions can oxidize drags such as timolol and can cause serious eye damage and eye irritation.

[0053] FIGS. 5-8 show specific examples of types of shielding materials and examples of different positions of the shielding materials within the body 12. The shielding material(s) 16 can act as an intermediate insulating layer, shielding and protecting the one or more drag(s) 14, and / or one or more other components of the ophthalmic device 40, from degradation and / or shielding and protecting the eye from irritants. The shielding material(s) 16 can be positioned as barrier layers (e.g., solid films) in the reservoir 26 between the metal cap 28 and the one or more drag(s) 14) and / or dispersed (e.g., as particles) in at least a portion of the body 12 of the ophthalmic device 40. The shielding material(s) 16 can be, depending on degradation to be prevented, a biocompatible pure metal or metal alloy, which is different from the metal of the metal cap 28, and / or a water dissolvable / degradable polymer. The shielding material can have a thickness, for example, between 100 nm and 10 pm if a biocompatible metal or metal alloy, or between 1 m and 100 pm if a water dissolvable / degradable polymer. However exact ranges of thickness may depend on material and properties of the one or more drug(s) 14. The shielding material(s) 16 can not interfere with the dissolution process of the metal cap (e.g., only act defensively). The shielding material(s) 16 can delay the release of the one or more drugs) 14 from the reservoir 26 for a time, but do not affect the diffusion kinetics of the one or more drugs out of the reservoir and towards the eye.

[0054] FIG. 5 shows an example ophthalmic device 50 where the shielding material 16 is positioned as a barrier layer within the reservoir 26 between the one or more drug(s) 14 and the metal cap 28. The barrier layer of shielding material 16 is made of a metal and / or a metal alloy, different from the metal of the metal cap 28, that can interact with one or more degradation sources 18 formed by the electrodissolution of the metal cap. It should be understood that harmful reaction product(s) are an example of degradation source(s) 18 that are used for ease of description. The metal of the barrier layer shielding material 16 can be, for example, magnesium (Mg), zinc (Zn), and / or an alloy of magnesium and / or zinc. The metal barrier layer shielding material 16 can interact (e.g., react) with and neutralize one or more harmful reaction products from the electrodissolution of the metal cap 28. The interaction between the metal barrier layer shielding material 16 and the one or more harmful reaction products can produce non-harmful reaction products that do not degrade the one or more drug(s) 14 and / or damage the eye and / or damage one or more components of the ophthalmic device 50.

[0055] Element A of FIG. 5 shows the metal cap 28 receiving the electrical signal from the signal generator 22 to trigger the active release of the one or more drug(s) 14 from the reservoir 26 (e.g., in response to a time, a manual input, a sensor input, or the like) at time T1 . Element B illustrates that the electrochemical reaction of the electrical signal and the metal cap 28 can form one or more reaction product(s) which, immediately on formation are blocked from contacting the one or more drug(s) 14 in the reservoir 26 by the metal barrier layer shielding material 16 at time T2. The shielding material 16 can then, as shown in FIG. 5, element C, interact with the one or more harmful reaction product(s) and form neutralized reaction product! s) 42 at time T3. (It should be understood that Tl, T2, and T3 can be different times than those of FIG. 4 and 6-8, but the times can be common. As an example, the metal cap 28 can be gold (e.g., a thin gold film) and the one or more harmful reaction products can include at least tctrachloroauratc(III) anions ([AuCU]’). The shielding material 16 can react with the tetrachloroaurate(III) anions to form non-harmful reaction products.

[0056] When the shielding material 16 is Magnesium (Mg): yields

[0057] [AuCl4] + Mg - > Mg + Cl + Au

[0058] Where: [AuCU]’ = tetrachloroaurate(III) anion; Mg = magnesium; Mg2+= magnesium cation; Cl’ = chloride ion; Au = gold

[0059] The tetrachloroaurate(III) anions can react with the Magnesium of the shielding material 16, reducing the tetrachloroaurate(III) anions to produce non-harmful products including chloride anions, elemental gold molecules, and Magnesium cations. The chloride anions and / or Magnesium cations can dissolve in water or otherwise act non harmfully. The elemental gold is microscale and does not affect the drug diffusion or cause harm.

[0060] When the shielding material 16 is Zinc (Zn): yields > ,

[0061] [AUC14] ~ -I- Zn - > Zn2+-I- Cl~ + Au

[0062] Where Zn = zinc and Zn2+= zinc cation, while [AuCU]' = tetrachloroaurate(III) anion; Cl — chloride ion; Au = gold

[0063] The tetrachloroaurate(III) anions can react with the Zinc of the shielding material 16, reducing the tetrachloroaurate(III) anions to produce non-harmful products including chloride anions, elemental gold molecules, and Zinc cations. The chloride anions and / or Zinc cations can dissolve in water or otherwise act non harmfully. The chloride anions and / or Zinc cations can dissolve in water or otherwise act non harmfully. The elemental gold is microscale and does not affect the drug diffusion or more generally cause harm to the ophthalmic device and / or the eye.

[0064] FIG. 6 shows an example ophthalmic device 60 where the shielding material 16 is dispersed in at least a portion of the body 12 (in other words, suspended in the hydrogel). The dispersed shielding material can be positioned, for example, between the metal cap 28 covering the opening of the reservoir 26 and the side of the ophthalmic device 60 facing the eye of the wearer (not shown). The shielding material 16 is a metal or metal alloy, different from the metal of the metal cap 28, that can interact with one or dissolution source(s) 18 formed by the electrodissolution of the metal cap. It should be understood that harmful reaction product(s) are an example of degradation source(s) 18 that are used for ease of description. The metal of the dispersed shielding material 16 can be, for example, magnesium (Mg), zinc (Zn), and / or a magnesium and / or zinc alloy. The dispersed metal shielding material 16 can interact (e.g., react) with and neutralize one or more harmful reaction products from the electrodissolution of the metal cap 28. The interaction between the dispersed metal shielding material 16 and the one or more harmful reaction products can produce non-harmful reaction products that do not degrade the one or more drug(s) 14 and / or damage the eye and / or damage one or more components of the ophthalmic device 60.

[0065] Element A of FIG. 6 shows the metal cap 28 receiving the electrical signal from the signal generator 22 to trigger the active release of the one or more drug(s) 14 from the reservoir 26 (e.g., in response to a time, a manual input, a sensor input, or the like) at time Tl. At time T1 the dispersed metal shielding material 16 can be inactive. Element B illustrates that the electrochemical reaction of the electrical signal and the metal cap 28 can form one or more reaction product(s) which, can open the reservoir 26 to release the one or more drug(s) 14 at time T2. The dispersed metal shielding material 16 can interact with the one or more harmful reaction product(s) (as shown) and / or form neutralized reaction product(s) (like 42 from FIG. 5) to protect the one or more drug(s) 14 as the one or more drug(s) diffuse out of the reservoir 26 and towards the eye of the wearer (not shown).

[0066] FIG. 7 shows an example of ophthalmic device 70 having two different implementations of a metal shielding material 16. The shielding material 16 can be implemented simultaneously as both a barrier layer and as dispersed particles in the body 12. The barrier layer of the shielding material can be positioned in the reservoir 26 between the metal cap 28 and the one or more drug(s) 14. The dispersed metal shielding material 16 can be positioned in at least a portion of the body 12 of the ophthalmic device 70 between the metal cap 28 and the side of the ophthalmic device facing the eye (not shown). Alternatively, the barrier layer shielding material 16 can also be made of a polymer (described in more detail below with respect to FIG. 8). The shielding matcrial(s) 16 can be a metal or metal alloy different from the metal of the metal cap 28. For example, the shielding material(s) 16 can be Mg, Zn, or an alloy of Mg and / or Zn. Each implementation of the shielding material 16 (e.g., barrier layer or dispersed) can be the same or a different metals, but always different from the metal of the metal cap 28. The use of two (or more) shielding material 16 implementations can improve the protection of the one or more drug(s) 14. For example, the barrier layer shielding material 16 can protect the one or more drug(s) 14 while within the reservoir (e.g., from the degradation sources 18 that are the electrical signal, moisture ingress, and / or electrochemical reaction products) and the dispersed shielding material 16 can provide additional protection (e.g., from degradation sources 18 that are from electrochemical reaction products not neutralized by the barrier layer) to the one or more drug(s) as the one or more drug(s) diffuse from the reservoir 26 toward the eye. Both barrier layer and dispersed shielding material 16 can prevent harmful reaction products 18 from reaching the eye (e.g., by neutralizing the harmful reaction products).

[0067] Element A of FIG. 7 shows an example of the ophthalmic device 70 as the electrical signal is first applied to the metal cap 28 from the signal generator 22 at time Tl, before electrodissolution of the metal cap 28 begins. The shielding materials 16 are made of a metal or metal alloy different from the metal of the metal cap 28 and are positioned as (1) the barrier layer and (2) the dispersed particles in at least a portion of the body 12. Element B of FIG. 7 shows that the electrical signal from the signal generator 22 reacts with the metal cap 28 to form harmful reaction product(s) (an example degradation source 18) and that both the dispersed and barrier layer shielding material(s) 16 then interact with the harmful reaction products at time T2. The barrier layer shielding material 16 can stay in place until at least a time after the electrical signal has ended. The shielding material(s) 16 neutralize the harmful reaction product(s) to neutralized reaction product(s) 42 so that at time T3 (shown in Element C) the one or more drug(s) can freely and without degradation diffuse out of the opening of the reservoir 26, into the body 12, and toward the eye (not shown).

[0068] FIG. 8 shows an example ophthalmic device 80 where the shielding material 16 is implemented as a barrier layer of a biocompatible polymer material configured to naturally dissolve / degrade in an amount of water over a period of time. The polymer material can be, for example, polyethylene glycol (PEG), polyvinyl alcohol (PVA), poly(lactic-co-glycolic acid) (PLGA), or the like. The polymer barrier layer implementation of the shielding material 16 can be positioned in the reservoir 26 between the metal cap 28 and the one or more dmg(s) 14. The polymer barrier layer can electrically insulate the one or more drug(s) 14. Electrically insulating the one or more drug(s) 14 from conduction of the voltage of the electrical signal through the metal cap 28 and / or entering water as the metal cap dissolves (examples of degradation source 18) so the one or more drug(s) do not to receive a voltage and / or a harmful voltage) The polymer barrier layer can additionally and / or alternatively physically insulate the one or more drug(s) 14 by preventing moisture ingress for a time or preventing harmful reaction product(s) of the electrodissolution of the metal cap 28 from entering the reservoir (examples of degradation source 18). For example, the polymer barrier layer can repel the harmful reaction product(s) until the harmful reaction products have dispersed and / or are neutralized (e.g., by a dispersed shielding material such as described above but not shown here). The polymer barrier layer can dissolve or degrade after a time exposed to water after the dissolution of the metal cap 28. The time can depend on the type of polymer, the thickness of the polymer barrier layer, and / or the amount of water (e.g., from tears) reaching the polymer barrier layer. For example, the polymer can be engineered such that the time for dissolving and / or degrading in the amount of water in the body 12 can be longer than a dispersal time for the harmful reaction product(s). The polymer barrier layer can be designed to not interfere with the electrodissolution of the metal cap 28 or interfere with the dispersion kinetics of the one or more drug(s) 14 out of the reservoir 26 other than delaying the start time of the diffusion (e.g., instead of diffusing after the metal cap begins to electrodissolve the one or more drugs do not begin diffusing until after the polymer barrier layer begins to dissolve.

[0069] Element A of FIG. 8 shows the ophthalmic device 80 where the shielding material 16 is a polymer barrier layer positioned in the reservoir 26 between the metal cap 28 and the one or more drug(s) 14 at time T1 as the electrical signal is first applied from the signal generator 22. Element B of FIG. 8 shows a time T2 as the electrical signal causes the metal cap 28 to electrodissolve into harmful reaction product(s) (an example of degradation source 18). The polymer barrier layer implementation of shielding layer 16 can physically insulate the one or more drug(s) 14 in the reservoir 16 (e.g., from water (not shown) and the harmful reaction product(s) (shown bouncing off the shielding material)) and / or electrically insulate the one or more drug(s) in the reservoir from the voltage of the electrical signal (examples of degradation sourcc(s) 18). At time T3, a time after the dispersal time of the harmful reaction product(s) and after the polymer barrier layer shielding material 16 has dissolved / degraded, the one or more drug(s) 14 can freely and without degradation diffuse out of the opening of the reservoir 26, into the body 12, and toward the eye (not shown).

[0070] IV. Methods

[0071] Another aspect of the present disclosure can include method 90 (FIG. 9) for protecting one or more drugs actively released from an ophthalmic device incorporating a shielding material (and, optionally, one or more components of the ophthalmic device) from degradation and / or the eye of the wearer of the ophthalmic device from irritation caused by the active release. The method 90 can be executed with any example of the ophthalmic device 30-80 described above with respect to FIGS. 3-8. Additional methods can include methods of manufacturing the ophthalmic devices 30-80. It should be understood that while the below description refers to a single reservoir, an ophthalmic device can include a plurality of reservoirs activatable singularly or in combination, which can all include a shielding material, which can be the same and / or different.

[0072] The method 90 is illustrated as process flow diagram with flowchart illustrations. For purposes of simplicity, the method 90 is shown and described as being executed serially; however, it is to be understood and appreciated that the present disclosure is not limited by the illustrated order as some steps could occur in different orders and / or concurrently with other steps shown and described herein. Moreover, not all illustrated aspects may be required to implement the method 90.

[0073] The method 90 illustrates / describes a “two step” method for actively releasing one or more drugs from a reservoir within a contact lens while preventing degradation of the one or more drug, irritation to the eye, and / or degradation of one or more components of the ophthalmic device. At step 92, active release of the one or more drugs can be triggered by activating dissolution of a cap covering an opening of a reservoir housing the one or more drugs within the ophthalmic device (see e.g., FIG. 4). If the cap is a metal cap (e.g., a thin metal film such as a gold thin film electrode), then the activation of the dissolution can be, for example, sending an electrical signal of a given voltage to the metal cap. The electrical signal can be generated by a signal generator in response to an input. The input can be, for example, a manual input, a timebased input (e.g., a controller of the ophthalmic device is programmed to initiate generation of an electrical signal every four hours, at 8 am every day, or the like), a physiological sensor input as part of a control loop (e.g., a controller of the ophthalmic device is programmed to generate the electrical signal when a measured intraocular pressure exceeds or is lower than a given interocular pressure range, or the like), or the like. In this example the generator and the metal cap are in electrical communication. At step 94 the cap can dissolve in response to the application of the activated trigger (e.g., the electrical signal). In the metal cap example, the dissolution is electrodissolution (e.g., an electrochemical reaction between the electrical signal at a given voltage and the metal cap). Electrodissolution of the metal cap can form electrochemical reaction products, which may be harmful to the one or more drug(s), one or more components of the ophthalmic device, and / or the eye of the wearer of the ophthalmic device (depending on the compositions of the metal cap, the one or more drugs, and the one or more components of the ophthalmic device). For example, the electrodissolution of a gold cap of the ophthalmic device (which can include an Ag-AgCl return electrode) can produce tetrachloroaurate ions that can oxidize certain glaucoma drugs such as timolol and / or can cause serious eye damage and eye irritation.

[0074] The ophthalmic devices (e.g., shown in FIGS. 3-8) include at least one shielding material positioned within the ophthalmic device configured to protect from degradation and / or irritation. For example, the shielding material can be a solid film positioned in a reservoir of the ophthalmic device between the metal cap covering an opening of the reservoir and the one or more drug stored in the reservoir. In another example, the shielding material can be particles dispersed in at least a portion of a body of the ophthalmic device. The dispersed particles of shielding material can be positioned at least between the metal cap and side of the ophthalmic device facing the eye. In some instances, both dispersed particles of shielding material and barrier layer(s) can be implemented in combination. The shielding material can be a pure metal or a metal alloy (e.g., Mg, Zn, an alloy of Mg and / or Zn, or the like) that is a different metal than the metal of the metal cap and / or a water dissolvable / degradable biocompatible polymer (e.g., polyethylene glycol (PEG), polyvinyl alcohol (PVA), poly(lactic-co-glycolic acid) (PLGA), or the like). During manufacture of the ophthalmic device the shielding material(s) can be introduced into the reservoir and / or the body of the ophthalmic device. For instance, a water dissolvable and / or degradable polymer barrier layer can be deposited in a liquid form that then solidifies into a film. The deposition can be, for example, on the metal cap (on the inner side facing the drug) before the metal cap is placed over the opening of the reservoir. In another instance the deposition can be directly into the reservoir before the opening of the reservoir is capped by the metal cap. In another instance, a metal barrier layer can be positioned in the reservoir between the metal cap and the one or more drug(s) by sputtering and / or evaporation techniques. A dispersed metal particle (e.g., nano or micron sized) shielding material can be uniformly dispersed in the hydrogel monomer of at least a portion the body before crosslinking the hydrogel or mixed with the water dissolvable / degradable polymer solutions and dispersed in the reservoir.

[0075] At step 96, degradation sources can be absorbed and / or the drug can be insulated from degradation by the shielding material. Degradation sources can include the harmful electrochemical reaction products discussed above, the electrical signal used to trigger the electrodissolution, and / or moisture ingress. For instance, the electrical signal can have a voltage necessary to electrodissolve the metal cap, but the voltage necessary to electrodissolve the metal cap can be disruptive itself. If the one or more drug(s) are in contact with the metal cap when the electrical signal is received by the metal cap, then the electrical signal can be conducted to the drug and can degrade the one or more drugs. Additionally, if water from tears of the eye diffused into the body of the ophthalmic device enters the reservoir through a partially dissolved metal cap while the electrical signal is still being received by the metal cap, then the electrical signal can be conducted to the one or more drug(s) through the water and can degrade the one or more drugs. In another instance, water from the tears of the eye may degrade certain drugs (e.g., if interacts with the one or more drug(s) too soon, if too much water dilutes the one or more drug(s), etc.). Additionally, moisture ingress into the drug reservoir may dissociate a portion of a solid state drug into an aqueous state more apt to react in an electrochemical reaction. As another example, the electrochemical reaction products formed by the electrodissolution of the metal cap can be harmful to the one or more drug(s), one or more components of the ophthalmic device, and / or the eye. The following are several concrete examples based on the metal cap being made of gold. In one instance, timolol, a common drug for treatment of glaucoma, oxidizes at +1.0 V vs. Ag / AgCl. If the metal cap 28 is a thin film gold cap, then the gold cap can begin a dissolution reaction around +1.2 V vs. Ag / AgCl, leading to a risk of drug degradation from the electrical signal needed to dissolve the gold cap. In another instance, irreversible oxidation of brimonidine, another drug for treatment of glaucoma, can occur at +.36 V and + 1.25 V, If the metal cap 28 is a thin film gold cap, then there can be a risk of drug degradation from the electrical signal as well. In another example when the metal cap 28 is gold, the electrodissolution of the gold can produce reactions products such as tetrachloro aurate ions. Tetrachloroaurate ions can oxidize drugs such as timolol and can cause serious eye damage and eye irritation.

[0076] As described in depth above with respect to the example ophthalmic devices in FIGS. 5- 8, the shielding material(s) can absorb or insulate the drug from degradation. For example, a dispersed particle metal shielding material can interact with harmful electrochemical reaction products formed by the electrodissolution of the metal cap to neutralize the harmful electrochemical reaction products into non-harmful products. A barrier layer made of a metal shielding material can also interact with harmful electrochemical reaction products formed by the electrodissolution of the metal cap to neutralize the harmful electrochemical reaction products into non-harmful products. The barrier layer made of a metal shielding material can additionally act as physical and / or electrical insulator to insulate the one or more drugs in the reservoir from the electrical signal and / or moisture ingress until the electrical signal is done and any harmful electrochemical reaction products have at least partially dissipated. A polymer barrier layer can also act as a physical and / or electrical insulator to insulate the one or more drags in the reservoir from the electrical signal and / or moisture ingress until the electrical signal is done and any harmful electrochemical reaction products have at least partially dissipated.

[0077] At step 98, the one or more drag(s) can be released from the reservoir with the dissolution of any barrier layer between the one or more drug(s) and the opening no longer blocked by the metal cap. A polymer barrier layer can dissolve after a period of time exposed to the water in the ophthalmic device (e.g., from the tears of the eye). The period of time can be at least longer than the Lime it takes for the harmful electrochemical reaction products to disperse (and / or be neutralized if used in conjunction with a dispersed metal particle shielding material). A metal barrier layer can dissolve in water as metal ions after neutralizing the harmful electrochemical reaction products. Optionally, a second triggering mechanism could be used to remove any remaining barrier layer. The barrier layers can be designed to not affect the diffusion kinetics of the one or more drug(s) out of the reservoir and toward the eye other than the delayed release. The one or more dnig(s) released from the reservoir can treat and / or alleviate a symptom, illness, or disorder of the eye.

[0078] From the above description, those skilled in the art will perceive improvements, changes, and modifications. Such improvements, changes and modifications are within the skill of one in the art and are intended to be covered by the appended claims.

Claims

The following is claimed:

1. An ophthalmic device comprising: a body; a reservoir positioned within the body and configured to store at least one drug; a metal cap configured to cover an opening of the reservoir and to dissolve to release the at least one drug from the reservoir, wherein the metal cap dissolves into at least one reaction product, wherein the metal cap is configured to dissolve in response to receiving an electrical signal; and a shielding material configured to protect the drug from degradation when the metal cap dissolves, wherein the degradation is due to the at least one reaction product, the electrical signal, and / or water from an eye.

2. The ophthalmic device of claim 1 , wherein the shielding material is configured as a barrier layer between the metal cap and the at least one drug in the reservoir and / or is dispersed within at least a portion of the body, wherein the shielding material comprises another metal different from the metal cap.

3. The ophthalmic device of claim 2, wherein the other metal comprises Magnesium and / or Zinc.

4. The ophthalmic device of claim 3, wherein the metal cap is gold and the at least one reaction product comprises tetrachloroaurate(lll) anions, wherein the tetrachloroaurate (III) anions react with the Magnesium and / or Zinc of the shielding material to produce non-harmful products including chloride anions, elemental gold molecules, and Magnesium cations and / or Zinc cations.

5. The ophthalmic device of claim 1, wherein the shielding material is configured as a barrier layer between the metal cap and the at least one drug in the reservoir, wherein the shielding material is a polymer configured to dissolve or degrade in water over time.

6. The ophthalmic device of claim 5, wherein the polymer electrically and / or physically insulates the at least one drug from the at least one reaction product.

7. The ophthalmic device of claim 5, wherein the polymer dissolves or degrades after a time exposed to water after the dissolution of the metal cap.

8. The ophthalmic device of claim 7, wherein the time is longer than a dispersal time for the at least one reaction product.

9. The ophthalmic device of claim 5, wherein the polymer comprises at least one of PEG, PVA, or PLGA.

10. The ophthalmic device of claim 1, wherein the dissolution process proceeds without interference from the shielding material.

11. The ophthalmic device of claim 1, wherein the shielding material is configured to delay release of the at least one drug from the reservoir for a time without affecting diffusion kinetics of the at least one drug out of the reservoir and towards the eye.

13. The ophthalmic device of claim 1, wherein the shielding material comprises a first shielding material and a second shielding material, wherein the first shielding material comprises another metal different from the metal cap and the second shielding material comprises a polymer.

14. The ophthalmic device of claim 13, wherein the first shielding material is dispersed within at least a portion of the body and the second shielding material is configured as a barrier layer-between the metal cap and the at least one drug in the reservoir.

15. A system for active release of at least one drug from an ophthalmic device, the system comprising: a signal generator configured to generate an electrical signal;at least one reservoir positioned within a body of the ophthalmic device, wherein each of the at least one reservoir is configured to store at least one drug and configured to have an opening covered by a metal cap, wherein the metal cap is configured to, in response to receiving the electrical signal from the signal generator, undergo an electrochemical reaction and dissolve to release the at least one drug from the reservoir, wherein the metal cap dissolves into at least one reaction product; and a shielding material configured to protect the at least one drug in the at least one reservoir from degradation when the metal cap dissolves, wherein the degradation is due to the at least one reaction product, the electrical signal, and / or water from an eye.

16. The system of claim 15, wherein the ophthalmic device is a contact lens comprising a hydrogel body, wherein after release from the at least one reservoir, the at least one drug diffuses from the contact lens to an eye.

17. The system of claim 15, wherein the shielding material comprises another metal, different from the metal cap, and is configured to be positioned as barrier layer between the metal cap and the at least one drug in each of the at least one reservoir and / or is dispersed within at least a portion of a body of the ophthalmic device, wherein the shielding material interacts with the at least one reaction product to neutralize at least one harmful aspect of the at least one reaction product.

18. The system of claim 17, wherein the metal cap is gold, the other metal comprises magnesium and / or zinc, and the at least one reaction product comprises tetrachloroaurate(III) anions, wherein the tetrachloroaurate(III) anions react with the magnesium and / or the zinc of the shielding material to produce non-harmful products including chloride anions, elemental gold molecules, and magnesium cations and / or zinc cations.

19. The system of claim 15, wherein the shielding material is configured as a barrier layer between the metal cap and the at least one drug in the at least one reservoir to electrically and / orphysically insulate the at least one drug from the at least one reaction product for at least a period of time of the electrochemical reaction, wherein the shielding material is a polymer configured to dissolve or degrade in water over time.

20. The system of claim 19, wherein the period of time is longer than a dispersal time for the at least one reaction product.

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