Extended release biodegradable ocular implants

Abstract

Biodegradable implants sized and suitable for implantation in an ocular region or site and methods for treating ocular conditions. The implants provide an extended release of an active agent at a therapeutically effective amount for a period of time between 50 days and one year, or longer.

Description

BACKGROUND[0001]This invention relates to implants and methods for treating an ocular condition. In particular the present invention relates to implants and methods for treating an ocular condition by implanting into an ocular region or site an extended release bioerodible implant comprising an active agent and a bioerodible polymer. The bioerodible implants of this invention have varying and extended release rates to provide for improved kinetics of release of one or more active (therapeutic) agents over time.[0002]An ocular condition can include a disease, aliment or condition which affects or involves the eye or one of the parts or regions of the eye. Broadly speaking the eye includes the eyeball and the tissues and fluids which constitute the eyeball, the periocular muscles (such as the oblique and rectus muscles) and the portion of the optic nerve which is within or adjacent to the eyeball. An anterior ocular condition is a disease, ailment or condition which affects or which i...

AI Technical Summary

Benefits of technology

[0048]“Suitable for insertion (or implantation) in (or into) an ocular region or site” with regard to an implant, means an implant which has a size (dimensions) such that it can be inserted or implanted without causing excessive tissue damage and without unduly physically interfering with the existing vision of the patient into which the implant is implanted or inserted.

[0051]In other variations, bioerodible implants according to the present invention are prepared using two or more different bioerodible polymers each having different release characteristics. In one variation, a first quantity of the drug or active agent is blended with a first polymer and the resultant material is extruded and then broken into particles which are then blended with an additional quantity of the drug or active agent and the same or a second polymer to form the final bioerodible implant, either by extrusion, injection molding or direct compression. The resultant implant has a release profile different than that of an implant created by initially blending the polymers together and provides for continual or substantially continual release of active agent at levels corresponding to at least about 10 ng / ml of dexamethasone or dexamethasone equivalent for at least about 60 days.

[0061]In another embodiment a bioerodible implant for treating a ocular condition, the bioerodible implant can be made by: (a) blending (followed by extruding, injection molding or the like) a steroidal anti-inflammatory drug and a first bioerodible polymer to form a first solid material; (b) breaking the solid material into particles; (c) blending (followed by extruding, injection molding or the like) the particles with the steroidal anti-inflammatory drug and a second bioerodible polymer to form a bioerodible implant, wherein the bioerodible implant can release a therapeutic level of the active agent at a substantially continuous rate for a period time between about 50 days and about 1 year. Such a bioerodible implant can substantially continuously release the steroidal anti-inflammatory drug at a dexamethasone equivalent level corresponding to at least 10 ng / ml for a period of at between 50 days and one year. For example, the bioerodible implant can continuously releases the steroidal anti-inflammatory drug at a dexamethasone equivalent corresponding to at least 50 ng / ml for a period of at least about 50 days.

Problems solved by technology

Macular degeneration results in a break down the macula, the light-sensitive part of the retina responsible for the sharp, direct vision needed to read or drive.

The wet form of the disease usually leads to more serious vision loss.

Macular degeneration can produce a slow or sudden painless loss of vision.

This leakage causes retinal cells to die and creates blind spots in central vision.

Macular edema (“ME”) can result in a swelling of the macula.

A major problem with topical and oral drug administration is the inability of the drug to achieve an adequate (i.e. therapeutic) intraocular concentration.

Unfortunately, these high drug plasma levels commonly lead to systemic side effects such as hypertension, hyperglycemia, increased susceptibility to infection, peptic ulcers, psychosis, and other complications.

Additionally, delivery to the eye of a therapeutic amount of an active agent can be difficult, if not impossible, for drugs with short plasma half-lives since the exposure of the drug to intraocular tissues is limited.

In turn, this repetitive process increases the potential for side effects such as retinal detachment, endophthalmitis, and cataracts.

U.S. Pat. No. 6,217,895 discusses a method of administering a corticosteroid to the posterior segment of the eye, but does not disclose a bioerodible implant.

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