A treatment for dry eye and other eye problems using a plug system or a delivery system. The plug system comprises solid, porous or hollow microcapsules composed of a biodegradable biocompatible polymer. The capsules are stored in the form of a powder that can be suspended in an aqueous carrier solution or dispersed in a gel or an ointment. Alternatively a biodegradable biocompatible capsule having a treating agent encapsulated within a polymer shell or a polymer sphere, again stored in the form of a powder that can be suspended in an aqueous carrier solution or dispersed in a gel or an ointment. The plug system prevents excretion of the capsules and their size is larger then the punctum and to prevent entrance to the lachrymal excretory system. The treatment is slowly released into the eye through the polymer shell or sphere and/or gets secreted as the polymer degrades.

SUMMARY OF THE INVENTION

It has now been discovered that the above and other objects of the present invention may be accomplished in the following manner. Specifically, the present invention provides a technology that will reduce the re-application process of the dry eye treatment. This type of technology can be applied to various ophthalmic diseases such as glaucoma or postoperative conditions such as cataract surgery or refractive surgery.

The method of treatment for dry eyes employs a biodegradable biocompatible polymer capsule or capsules, that can be conveniently placed in the eye by the patient, to avoid drainage of the natural tear by blocking the lachrymal excretory system. The treatment for dry eyes employs a biodegradable biocompatible polymer capsule or capsules with an agent contained within them.

The polymer microcapsule may also include a treating agent whereby the polymer microcapsule is placed in the conjuntival sac of the patient's eye and releases the agent over a fixed period of time while the polymer microcapsule degrades.

Ophthalmic diseases that are treatable by the present invention, in addition to dry eye problems, include, glaucoma, post-operative conditions like cataract surgery or refractive surgery.

There are two parts to the present invention: a plug based system and a drug delivery based system. Both parts employ a biodegradable, biocompatible capsule.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIG. 1 (see Original Patent), tears are secreted from the top left corner and the lachrymal gland 11, flow across the corneal surface of the eye 13 and the eyeball through the punctum 17 into the tear ducts 15 where they are excreted into the nose. In FIG. 2, the lachrymal excretory system is shown, where A is the punctum, B is the ampulla, C is the canaliculus, D is the common canaliculus, E is the lachrymal sac and F is the nasolacrimal duct.

As FIG. 2 (see Original Patent)depicts, the punctum (0.3 0.5 mm in diameter) is the entrance of the tear to the lachrymal excretory system. Once the tear has gone through the punctum it passes through the ampulla (2 mm in length) and then to the canaliculi (8 mm in length), where it then ends up in the common canaliculi prior to entering the lachrymal sac (10 mm) and finally existing through the nasolacrimal duct (12 mm in length).

FIG. 3 (see Original Patent) illustrates three versions or embodiments of one embodiment or component of the present invention, showing the plug system. One embodiment comprises solid A, porous B, or hollow C, microcapsules that are in the size range of 0.01 mm to 1 mm. The capsules are composed of a biodegradable biocompatible polymer. The capsules are stored in the form of a powder that can be suspended in an aqueous carrier solution or dispersed in a gel or an ointment.

The purpose of these capsules is to plug the lachrymal excretory system. They may plug the system at the punctum, the ampulla, the canaliculi, lachrymal sac or nasolacrimal duct. There are three ways to place these plug systems. They can be dispersed in an aqueous carrier solution, and placed into the eye in the form of drops, or dispersed in a gel or ointment and placed in the eye in the form of a gel or ointment. The capsules will flow to the lachrymal excretory system with the carrier solution in the same manner the natural tear would flow. The size of the capsules would cause them get lodged in the lachrymal excretory system, the most likely place that this would occur is in the punctum, however depending on the size of the capsules, they may pass the punctum and accumulate elsewhere in the lachrymal excretory system, where the plug would occur.

The drug delivery system shown in FIG. 4 (see Original Patent) is composed of a biodegradable biocompatible capsule (diameter of 0.01 mm to about 1 mm) associated with an agent. The drug delivery system capsule encapsulates an agent within a polymer shell A or within a polymer sphere B. The agent is anything used in the treatment of dry eyes can be a drop, gel or ointment. As with the plug system, the capsules are stored in the form of a powder that can be suspended in an aqueous carrier solution or dispersed in a gel or an ointment. The suspended capsules can be placed into the eye in the form of drops, and those dispersed in a gel or ointment can be placed in the eye in the form of a gel or ointment. The capsules will not get eliminated through the lachrymal excretory system for one of two reasons, they will be used with the plug system, which will prevent excretion of the capsules, or their size will be larger then the punctum and so their entrance to the lachrymal excretory system will be prevented. The drug delivery system works by slowly releasing the agent into the eye through the polymer shell or sphere and/or gets secreted as the polymer degrades. In this embodiment, the polymer microcapsule is placed in the conjuntival sac of the patient's eye and releases the agent over a fixed period of time while the polymer microcapsule degrades.

The life span of both the plug system and the drug delivery system will vary from hours to months depending on the material of which the capsule is composed and the different models used for each system. The plug system and the drug delivery systems can be used alone or in conjunction with each other depending on the medical situation. The number of capsules used for each situation is also dependent on the medical situation.

The capsule or capsules may come as a dry powder suspended in an aqueous solution or dispersed in a gel or ointment. The biodegradable biocompatible polymer capsule or capsules are placed into the patient's eye by the patient or by the physician in the form of drops, gels or ointments.

The capsules are made by a known double emulsion method. The polymer is dissolved in a solvent. Water or a treating agent is suspended in the polymer solution and probe sonicated, producing the first emulsion. The emulsion is then homogenized in a surfactant solution, producing the second emulsion. Stirring them in a solvent solution then dries the capsules. The capsules are collected and dried by centrifugation and freeze-drying respectively.

The size of the capsules and the encapsulation is dependent on variations of time, temperature, material used to fabricate the capsules. These factors also play a role as to which of the capsule models will be made.

In one embodiment where the treatment uses drops, the dry capsule or capsules may be reconstituted by a Pharmacist (prior to dispensing of the drops) or by the physician or patient in an aqueous solution prior to use and applied to the patient's eyes through a dropper.

The aqueous solution of the present invention include saline, carboxymethylcellulose sodium, Dextran, hydroxypropyl methycellulose, propylene and glycerin, as well as any ingredients of commercially available artificial tears.

When the invention is used with either gels or ointments, the dry capsule or capsules are readily dispersed in the ointment or gel prior to use by the physician or patient and may then be applied to the patient's eyes as a gel or ointment. One preferred gel is carboxymethylcellulose sodium salt as sell as any commercially available gel. Ointment includes petreolatum, mineral oil and any ingredients of commercially available ointments.

A preferred biodegradable biocompatible polymer capsule or capsules are solid, hollow or porous capsules with diameters in the range of 0.01 mm to 1 mm. The biodegradable biocompatible polymer capsule contains artificial tear drops, ophthalmic gels, or ophthalmic ointments and the like.

In a preferred embodiment, the diameter of the capsule or capsules is smaller or larger than the diameter of the punctum.

The polymer capsule or capsules of the present invention may be made of any biodegradable, biocompatible polymer.

Hydrogel based networks which may be biodegradable (enzymatic or hydrolytic) can be designed to increase in size in a controlled manner through swelling, which can improve the occlusion of the punctum. The material swells when exposed to an aqueous medium such as the fluids in the eye, and thus swell when in position. This material can be biodegradable or non biodegradable, since, over time, the biodegradable microcapsule will reduce in size, eventually exiting the punctum.

Preferred polymers are selected from the group consisting of a polylactide, polyglycolide, polycaprolactone, copolymers of polylactide and polyglycolide, copolymers of lactide and lactone, polysaccharides, polyanhydrides, polystyrenes, polyalkylcyanoacrylates, polyamides, polyphosphazenes, poly(methylmethacrylate), polyurethanes, copolymers of methacrylic acid and acrylic acid, copolymers of hydroxyethylmethacrylate and methylmethacrylate, polyaminoacids and polypeptides.
 

Claim 1 of 17 Claims

1. A method for treating dry eye symptoms of a patient in the lachrymal excretory system of said patient, comprising the steps of: forming a biodegradable, biocompatible polymer into a microcapsule of from about 0.1 mm to about 1.0 mm and including a treating agent therein; placing said polymer microcapsule in a carrier solution to form a treating solution for placement of said polymer microcapsule in the eye of a patient; and positioning said polymer microcapsule to become lodged in the lachrymal excretory system of said patient for a period of time while said polymer microcapsule biodegrades.

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