U.S. patent application number 16/502359 was filed with the patent office on 2019-10-24 for sustained delivery of therapeutic agents to an eye compartment.
The applicant listed for this patent is The Johns Hopkins University. Invention is credited to Ashley Behrens, Justin S. Hanes, Renata T. Kashiwabuchi, Yasin A. Khan, Samuel K. Lai, Peter J. McDonnell.
Application Number | 20190321297 16/502359 |
Document ID | / |
Family ID | 44507600 |
Filed Date | 2019-10-24 |
United States Patent
Application |
20190321297 |
Kind Code |
A1 |
McDonnell; Peter J. ; et
al. |
October 24, 2019 |
SUSTAINED DELIVERY OF THERAPEUTIC AGENTS TO AN EYE COMPARTMENT
Abstract
Compositions and methods for treating eye disorders by
administering a drug delivery system into an eye compartment of the
patient, wherein the drug delivery system contains a particle
containing a core; a coating associated with the particle, wherein
the coating is covalently or non-covalently associated with the
particle and presents a hydrophilic region to the environment
around the particle; and a therapeutic agent are disclosed. The eye
compartment can exhibit reduced inflammation or TOP after
administration of the drug delivery systems to a patient than if a
drug delivery system including an uncoated particle were
administered to the patient.
Inventors: |
McDonnell; Peter J.;
(Baltimore, MD) ; Khan; Yasin A.; (Baltimore,
MD) ; Lai; Samuel K.; (Carrboro, NC) ;
Kashiwabuchi; Renata T.; (Baltimore, MD) ; Behrens;
Ashley; (Baltimore, MD) ; Hanes; Justin S.;
(Baltimore, MD) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Johns Hopkins University |
Baltimore |
MD |
US |
|
|
Family ID: |
44507600 |
Appl. No.: |
16/502359 |
Filed: |
July 3, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15884158 |
Jan 30, 2018 |
10369107 |
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16502359 |
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15138132 |
Apr 25, 2016 |
9937130 |
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15884158 |
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14521904 |
Oct 23, 2014 |
9566242 |
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15138132 |
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13581454 |
Aug 27, 2012 |
8889193 |
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PCT/US2011/026321 |
Feb 25, 2011 |
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14521904 |
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61308035 |
Feb 25, 2010 |
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61308042 |
Feb 25, 2010 |
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61308053 |
Feb 25, 2010 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K 9/5153 20130101;
A61K 47/60 20170801; A61K 31/52 20130101; A61P 27/02 20180101; A61K
9/0048 20130101; A61K 47/6921 20170801; A61K 45/06 20130101; A61K
47/58 20170801; A61K 9/1641 20130101; A61K 47/6931 20170801; A61K
9/1676 20130101; A61P 27/00 20180101; A61K 9/5146 20130101; A61K
9/0051 20130101; A61K 9/1647 20130101; A61K 9/5026 20130101; A61K
9/5031 20130101; A61K 31/519 20130101 |
International
Class: |
A61K 9/16 20060101
A61K009/16; A61K 47/60 20060101 A61K047/60; A61K 9/00 20060101
A61K009/00; A61K 47/69 20060101 A61K047/69; A61K 45/06 20060101
A61K045/06; A61K 9/50 20060101 A61K009/50; A61K 31/52 20060101
A61K031/52; A61K 31/519 20060101 A61K031/519; A61K 9/51 20060101
A61K009/51; A61K 47/58 20060101 A61K047/58 |
Claims
1-60. (canceled)
61. An injectable composition for intravitreal injection into the
vitreous chamber of the eye of a patient in need thereof,
comprising microparticles in a sterile suspension suitable for
intravitreal injection wherein the microparticles have a diameter
of about 50 microns or less and comprise: (i) a core comprising a
mixture of biodegradable polymers polylactide-co-glycolide and
poly(lactic acid); (ii) a coating non-covalently associated with
the core wherein the coating is a block-copolymer having a
hydrophilic region and a hydrophobic region and wherein the
hydrophilic region is polyethylene glycol; and (iii) a
therapeutically effective amount of a therapeutic agent wherein the
injectable composition provides sustained release of the
therapeutic agent into the eye compartment for at least two months
and wherein the eye compartment exhibits at least 10% less
inflammation or intraocular pressure than if the particle were
uncoated for at least about 30 days post-administration.
62. The injectable composition of claim 61, wherein the composition
includes a suspending agent.
63. The injectable composition of claim 61, wherein the therapeutic
agent delivered is an anti-VEGF agent.
64. The injectable composition of claim 61, wherein the therapeutic
agent delivered is selected from timolol, betaxolol, bromonidine,
and dorzolamide.
65. The injectable composition of claim 61, wherein the injectable
composition provides sustained release of the therapeutic agent
into the vitreous chamber for at least three months.
66. The injectable composition of claim 61, wherein the injectable
composition provides sustained release of the therapeutic agent
into the vitreous chamber for at least six months.
67. The injectable composition of claim 61, wherein the injectable
composition provides sustained release of the therapeutic agent
into the vitreous chamber for at least nine months.
68. The injectable composition of claim 61, wherein the
microparticles have a diameter of about 30 microns or less.
69. A drug delivery system for intravitreal injection into the
vitreous chamber of the eye of a patient in need thereof,
comprising a device containing a needle for injection and
microparticles in a sterile suspension suitable for intravitreal
injection wherein the microparticles have a diameter of about 50
microns or less and comprise: (i) a core comprising a mixture of
biodegradable polymers polylactide-co-glycolide and poly(lactic
acid); (ii) a coating non-covalently associated with the core
wherein the coating is a block-copolymer having a hydrophilic
region and a hydrophobic region and wherein the hydrophilic region
is polyethylene glycol; and (iii) a therapeutically effective
amount of a therapeutic agent wherein the drug delivery system
provides sustained release of the therapeutic agent into the eye
compartment of the patient for at least two months and wherein the
eye compartment exhibits at least 10% less inflammation or
intraocular pressure than if the particle were uncoated for at
least about 30 days post-administration.
70. The drug delivery system of claim 69, wherein the composition
includes a suspending agent.
71. The drug delivery system of claim 69, wherein the therapeutic
agent delivered is an anti-VEGF agent.
72. The drug delivery system of claim 69, wherein the therapeutic
agent delivered is selected from timolol, betaxolol, bromonidine,
and dorzolamide.
73. The drug delivery system of claim 69, wherein the drug delivery
system provides sustained release of the therapeutic agent into the
vitreous chamber of the eye for at least three months.
74. The drug delivery system of claim 69, wherein the drug delivery
system provides sustained release of the therapeutic agent into the
vitreous chamber of the eye for at least six months.
75. The drug delivery system of claim 69, wherein the drug delivery
system provides sustained release of the therapeutic agent into the
vitreous chamber of the eye for at least nine months.
76. The drug delivery system of claim 69, wherein the
microparticles have a diameter of about 30 microns or less.
77. A method for the treatment of an eye disorder in a patient in
need thereof comprising administering an injectable composition by
intravitreal injection into the vitreous chamber, wherein the
injectable composition comprises microparticles in a sterile
suspension suitable for intravitreal injection wherein the
microparticles have a diameter of about 50 microns or less and
comprise: (i) a core comprising a mixture of biodegradable polymers
polylactide-co-glycolide and poly(lactic acid); (ii) a coating
non-covalently associated with the core wherein the coating is a
block-copolymer having a hydrophilic region and a hydrophobic
region and wherein the hydrophilic region is polyethylene glycol;
and (iii) a therapeutically effective amount of a therapeutic agent
wherein the injectable composition provides sustained release of
the therapeutic agent into the vitreous chamber for at least two
months and wherein the vitreous chamber exhibits at least 10% less
inflammation or intraocular pressure than if the particle were
uncoated for at least about 30 days post-administration.
78. The method of claim 77, wherein the disorder is macular
degeneration.
79. The method of claim 77, wherein the disorder is age-related
macular degeneration.
80. The method of claim 77, wherein the disorder is proliferative
diabetic retinopathy.
81. The method of claim 77, wherein the disorder is corneal
neovascularization.
82. The method of claim 77, wherein the patient is a human.
83. The method of claim 77, wherein the microparticles have a
diameter of about 30 microns or less.
84. The method of claim 77, wherein the injectable composition
provides sustained release of the therapeutic agent into the
vitreous chamber of the eye for at least three months.
85. The method of claim 77, wherein the injectable composition
provides sustained release of the therapeutic agent into the
vitreous chamber of the eye for at least six months.
86. The method of claim 77, wherein the injectable composition
provides sustained release of the therapeutic agent into the
vitreous chamber of the eye for at least nine months.
Description
TECHNICAL FIELD
[0001] The compositions and methods disclosed herein can be used
for treating eye disorders, for example by administering a drug
delivery system into an eye compartment of a patient.
BACKGROUND
[0002] Treatment of eye disorders can pose significant problems.
For example, the management of many corneal diseases requires that
therapeutic agents, such as drugs or other medications, remain at
therapeutic levels in the corneal tissue for extended periods of
time. Topical drops remain the most common route of drug
administration to the eye, especially the cornea. Certain patients,
however, including those patients having fungal and/or amoebic
infections of the cornea, as well as corneal transplant recipients,
require therapeutic doses of medications to be continuously
maintained in the corneal tissues. To achieve such therapeutic
doses of a particular medication in corneal tissues, such patients
are required to endure lengthy and arduous dosing regimens that
often involve topically instilling medications hourly.
[0003] The efficacy of topical dosing can be diminished by poor
patient compliance. The repeated administration of one or more
medications can also lead to toxicity, which can be related to
excess dosing of the medications and/or their preservative agents.
Injections of free-standing medications into the corneal stroma
also have been employed in certain situations. This approach,
however, fails to result in sustained presence of medications
within the therapeutic window due to rapid diffusion of the
medication out of the cornea. The combination of poor compliance
and poor penetration of topically-administered medications into the
corneal stroma can result in treatment failure, even when the
pathogenic organism or other cause of disease is known to be
"sensitive" to the therapy or should otherwise respond to the
medication being applied to the eye.
[0004] Such treatment difficulties are not only observed with
corneal diseases. Disorders common to the anterior chamber (AC) can
also pose problems. For example, cataract extraction is one of the
most commonly performed surgical procedures in the United States.
Both the incidence of cataracts and the frequency of their
extraction surgeries continue to rise. Anti-inflammatory agents and
antimicrobials both are required during the post-operative period
and typically must be administered for many weeks. Unfortunately,
the poor ocular bioavailability of these drugs often necessitates
complicated and arduous dosing regimens that can lead to poor
patient compliance, which, in turn, ultimately contributes to poor
surgical outcomes and other complications. Current state-of-the art
treatment involves sustained delivery systems that are injected
into the subconjunctival space at the end of surgery. However, such
sustained release drug systems afford limited intraocular
bioavailability of delivered medications due to barriers to drug
penetration. Further, medications delivered to an extraocular site,
even in a sustained manner, will have lower intraocular
bioavailability due to barriers that prevent penetration.
[0005] Injecting medications directly into the AC of the eye at the
end of surgery has been an alternative to topical treatment.
Free-standing medications injected into the AC, however, are
readily eliminated during aqueous humor clearance. As a result, the
retention of medications injected into the AC is short and their
bioavailability fails to meet clinical guidelines.
[0006] The delivery of medications to the posterior segment of the
eye has also been a challenge for ophthalmologists. Currently, the
successful management of many retinal diseases often requires
multiple intravitreal injections of medication per year. Retinal
diseases, such as diabetic retinopathy and age-related macular
degeneration, among others, continue to represent major causes of
irreversible vision loss in the United States. The treatment of
these conditions is complicated by the difficulty of delivering
medications to the retina. The direct delivery of drugs to the
vitreous chamber has become an important tool in the arsenal of
retinal disease management.
[0007] Unfortunately, the chronic and progressive nature of many
retinal diseases necessitates repeated injections to provide
continued treatment. The current regimens, which vary based on the
disease, its stage, and the medications used, can include up to six
intraocular injections per year. Each intravitreal injection,
however, is associated with the risk of developing serious and
vision-threatening infections and even traumatic retinal
injury.
SUMMARY
[0008] In one aspect, the invention provides methods for treating
eye disorders in a patient in need thereof. The methods can
include, for example, administering a drug delivery system into an
eye compartment of the patient, the drug delivery system having (i)
a particle including a core; (ii) a coating associated with the
particle, wherein the coating is covalently or non-covalently
associated with the particle and presents a hydrophilic region to
the environment around the particle; and (iii) a therapeutically
effective amount of a therapeutic agent, thereby treating the eye
disorder. In some embodiments, the eye compartment exhibits reduced
inflammation or IOP than if a drug delivery system using an
uncoated particle were administered to the patient. The
inflammation or IOP can be reduced by, for example, at least about
10%, or at least about 30%, or at least about 50%. In some
embodiments, the core includes a biocompatible polymer.
[0009] In some embodiments, the coating includes one or more
molecules having hydrophilic regions and hydrophobic regions. For
example, at least about 50% of the hydrophobic regions in the
coating molecules have a molecular mass of least about 2 kDa, or at
least about 3 kDa. The hydrophobic regions can include, for
example, PPO. The hydrophilic regions can include, for example,
PEG. The particles can have a diameter of, for example, less than
about 100,000 nm, or less than about 50,000 nm, or less than about
10,000 nm, or less than about 5,000 nm, or less than about 1,000
nm. In some embodiments, the particle has a diameter of about 200
nm.
[0010] The particle can include, for example, a biodegradable
polymer such as poly(lactic-co-glycolic acid). The coating can be,
for example, bound covalently to the particle, or it can be
non-covalently associated with the particle. In some embodiments,
the coating includes one or more of Pluronic P103, Pluronic P105,
and poloxamer 407.
[0011] In some embodiments, administering the drug delivery system
involves injecting the drug delivery system into an eye
compartment, such as the vitreous chamber, the sclera, the stroma
or the anterior chamber. The drug delivery system can include a
therapeutic agent such as one or more of an anti-inflammatory drug,
an antimicrobial agent, an anti-angiogenesis agent, an
immunosuppressant, an antibody, an antibody fragment, a steroid, a
chemotherapeutic agent, an ocular anti-hypertensive drug and
combinations thereof. In some embodiments, the drug delivery system
provides sustained release of the therapeutic agent over a period
of time, for example at least about 1 day, or at least about 1
week, or at least about 4 weeks.
[0012] In another aspect, the invention provides drug delivery
systems. The drug delivery system can include: (i) a particle
including a core; (ii) a coating associated with the particle,
wherein the coating is covalently or non-covalently associated with
the particle and presents a hydrophilic region to the environment
around the particle; and (iii) a therapeutically effective amount
of a therapeutic agent. The drug delivery system can be suitable
for administration into an eye compartment, such as the vitreous
chamber, the sclera, the corneal stroma and the anterior chamber.
The core can include, for example, a biocompatible polymer. In some
embodiments, the drug delivery system brings about reduced
inflammation or IOP when administered to the patient than if a drug
delivery system using an uncoated particle were administered to the
patient, for example by at least about 10%, or at least about 30%,
or at least about 50%. In some embodiments, the coating includes
one or more molecules having hydrophilic regions and hydrophobic
regions. For example, at least about 50% of the hydrophobic regions
in the coating molecules have a molecular mass of least about 2
kDa, or at least about 3 kDa. In some embodiments, the hydrophobic
regions comprise PPO. In some embodiments, the hydrophilic regions
comprise PEG. The particle can include, for example, a
biodegradable polymer such as polylactic-co-glycolic acid). The
coating can include, for example, one or more of Pluronic P103,
Pluronic P105 and poloxamer 407. The particles can have a diameter
of, for example, less than about 100,000 nm, or less than about
50,000 nm, or less than about 10,000 nm, or less than about 5,000
nm, or less than about 1,000 nm. In some embodiments, the particle
has a diameter of about 200 nm. In some embodiments, the
therapeutic agent is one or more of an anti-inflammatory drug, an
antimicrobial agent, an anti-angiogenesis agent, an
immunosuppressant, an antibody, an antibody fragment, a steroid, a
chemotherapeutic agent, an ocular anti-hypertensive drug and
combinations thereof. The drug delivery system can be suitable for
administration into the eye compartment by injection.
[0013] The drug delivery system can also include, for example, (i)
a substrate; (ii) a coating associated with the substrate, wherein
the coating presents a hydrophilic region to the environment around
the substrate; and (iii) a therapeutically effective amount of a
therapeutic agent. The drug delivery system can, for example, bring
about reduced inflammation when administered to the patient than if
a drug delivery system comprising an uncoated substrate were
administered to the patient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a graph depicting the inflammation profile in
female New Zealand white rabbits after intracameral injection of
several particle-coating combinations according to the compositions
and methods disclosed herein.
DETAILED DESCRIPTION
[0015] The presently disclosed subject matter may be embodied in
many different forms and should not be construed as limited to the
embodiments set forth herein. Indeed, many modifications and other
embodiments of the presently disclosed subject matter will come to
mind for one skilled in the art to which the presently disclosed
subject matter pertains having the benefit of the teachings
presented in the descriptions included herein. Therefore, it is to
be understood that the presently disclosed subject matter is not to
be limited to the specific embodiments disclosed and that
modifications and other embodiments are intended to be included
within the scope of the disclosed subject matter.
[0016] Although specific terms are employed herein, they are used
in a generic and descriptive sense only and not for purposes of
limitation. Unless otherwise defined, all technical and scientific
terms used herein have the same meaning as commonly understood by
one of ordinary skill in the art to which this presently described
subject matter belongs.
[0017] Following long-standing patent law convention, the terms
"a," "an," and "the" refer to "one or more" when used in this
application, including the claims. Thus, for example, reference to
"a subject" includes one or a plurality of subjects, unless the
context clearly is to the contrary (e.g., a plurality of subjects),
and so forth.
[0018] Throughout the specification and claim(s), the terms
"comprising," "having," "including," or "containing" and any
grammatical derivations thereof, are intended to be non-limiting,
i.e., they are inclusive or open-ended, such that recitation of
particular elements in a list does not exclude other like, but
unrecited, elements that can be substituted or added to the recited
elements.
[0019] For the purposes of this specification and appended claims,
unless otherwise indicated, all numbers expressing amounts, sizes,
dimensions, proportions, shapes, formulations, parameters,
percentages, parameters, quantities, characteristics, and other
numerical values used in the specification and claims, are to be
understood as being modified in all instances by the term "about"
even though the term "about" may not expressly appear with the
value, amount or range. Accordingly, unless indicated to the
contrary, the numerical parameters set forth in the following
specification and attached claims are not and need not be exact,
but may be approximate and/or larger, or smaller as desired,
reflecting tolerances, conversion factors, rounding off,
measurement error and the like, and other factors known to those of
skill in the art depending on the desired properties sought to be
obtained by the presently disclosed subject matter. For example,
the term "about," when referring to a value can be meant to
encompass variations of, in some embodiments, .+-.100%; in some
embodiments, .+-.50%; in some embodiments, .+-.20%; in some
embodiments, .+-.10%; in some embodiments, .+-.5%; in some
embodiments, .+-.1%; in some embodiments, .+-.0.5%; and in some
embodiments, .+-.0.1% from the specified amount, as such variations
are appropriate to perform the disclosed methods or employ the
disclosed compositions.
[0020] Further, the term "about" when used in connection with one
or more numbers or numerical ranges, should be understood to refer
to all such numbers, including all numbers in a range and modifies
that range by extending the boundaries above and below the
numerical values set forth. The recitation of numerical ranges by
endpoints includes all numbers, e.g., whole integers, including
fractions thereof, subsumed within that range (for example, the
recitation of 1 to 5 includes 1, 2, 3, 4, and 5, as well as
fractions thereof, e.g., 1.5, 2.25, 3.75, 4.1, and the like) and
any range within that range.
[0021] In one aspect, methods for treating one or more eye
disorders are disclosed. The methods can involve, for example,
administering a drug delivery system into an eye compartment of a
patient. In some embodiments, the drug delivery system can include:
i) a particle containing a core; ii) a coating disposed on the
surface of the particle, wherein the coating molecules have
hydrophilic regions; and iii) a therapeutic agent, for example a
therapeutically effective amount of a therapeutic agent. The
coating molecules can include, for example, hydrophobic regions. In
some embodiments, at least about 50% of the hydrophobic regions in
the coating molecules have a molecular mass of least about 2 kDa.
In some embodiments, the drug delivery system can include a
particle and a coating; and in some embodiments, a particle,
coating and therapeutic agent. The drug delivery system can
contain, for example, a pharmaceutically acceptable carrier. The
drug delivery system can be suitable for administration into an eye
compartment of a patient, for example by injection into the eye
compartment. In some embodiments, the core includes a biocompatible
polymer. As used herein, unless the context indicates otherwise,
"drug delivery system" and "particle composition" can be used
interchangeably.
[0022] The particle in the drug delivery system can be of various
sizes. The appropriate particle size can vary based on the method
of administration, the eye compartment to which the drug delivery
system is administered, the therapeutic agent employed and the eye
disorder to be treated, as will be appreciated by a person of skill
in the art in light of the teachings disclosed herein. For example,
in some embodiments the particle has a diameter of at least about 1
nm, or from about 1 nm to about 50 microns. The particle can also
have a diameter of, for example, from about 1 nm to about 30
microns; or from about 1 nm to about 10 microns; or from about 1 nm
to about 6 microns; from about 1 nm to about 5 microns; or from
about 1 nm to about 3 microns; or from about 1 nm to about 1000 nm;
or from about 25 nm to about 750 nm; or from about 50 nm to about
500 nm; or from about 100 nm to about 300 nm. In some embodiments,
the average particle size can be about 1 nm, about 10 nm, about 50
nm, about 100 nm, about 150 nm, about 200 nm, about 250 nm, about
300 nm, about 350 nm, about 400 nm, about 450 nm, about 500 nm,
about 550 nm, about 600 nm, about 650 nm, about 700 nm, about 750
nm, about 800 nm, about 850 nm, about 900 nm, about 950 nm, or
about 1000 nm, or about 2,000 nm, or about 5,000 nm, or about 6,000
nm, or about 10,000 nm, or about 20,000 nm, or about 50,000 nm, or
about 100,000 nm. In some embodiments, the particle size can be
about 100 microns or less, about 50 microns or less, about 30
microns or less, about 10 microns or less, about 6 microns or less,
about 5 microns or less, about 3 microns or less, about 1000 nm or
less, about 800 nm or less, about 600 nm or less, about 500 nm or
less, about 400 nm or less, about 300 nm or less, about 200 nm or
less, or about 100 nm or less. In some embodiments, the particle
can be a nanoparticle or a microparticle, as these terms are
defined herein. In some embodiments, the drug delivery system can
contain a plurality of particles. The particles can be all
nanoparticles, all microparticles, or a combination of
nanoparticles and microparticles.
[0023] In some embodiments, the drug delivery system includes a
particle comprising a core. The core can be, for example, a small
molecule, a polymer, a lipid, a protein, a carbohydrate, a viral
carrier, a virosome, a sterol, a liposome, a metal, a metal oxide
(e.g., silica), a quantum dot, a therapeutic agent in pure or
substantially pure form (e.g., in crystal form), and the like, as
well as any combination of any of the foregoing. The particle can
include, without limitation, one or more lipid-based drug
carriers.
[0024] The particles of the drug delivery system can include a
biocompatible polymer. As used herein, the term "biocompatible
polymer" encompasses any polymer that can be administered to a
patient without adverse effects to the patient, or for which any
adverse effects are deemed by a person having ordinary skill in the
art to be outweighed by the benefits brought about by the drug
delivery system in light of the mode of administration, the
therapeutic agent employed, and/or the eye disorder to be treated,
and also when considered in light of the availability of
alternative therapeutic regimen and their characteristics.
[0025] Examples of biocompatible polymers include but are not
limited to polystyrenes; poly(hydroxy acid); poly(lactic acid);
poly(glycolic acid); poly(lactic acid-co-glycolic acid);
poly(lactic-co-glycolic acid); poly(lactide); poly(glycolide);
poly(lactide-co-glycolide); polyanhydrides; polyorthoesters;
polyamides; polycarbonates; polyalkylenes; polyethylenes;
polypropylene; polyalkylene glycols; poly(ethylene glycol);
polyalkylene oxides; poly(ethylene oxides); polyalkylene
terephthalates; poly(ethylene terephthalate); polyvinyl alcohols;
polyvinyl ethers; polyvinyl esters; polyvinyl halides; poly(vinyl
chloride); polyvinylpyrrolidone; polysiloxanes; poly(vinyl
alcohols); poly(vinyl acetate); polyurethanes; co-polymers of
polyurethanes; derivativized celluloses; alkyl cellulose;
hydroxyalkyl celluloses; cellulose ethers; cellulose esters; nitro
celluloses; methyl cellulose; ethyl cellulose; hydroxypropyl
cellulose; hydroxy-propyl methyl cellulose; hydroxybutyl methyl
cellulose; cellulose acetate; cellulose propionate; cellulose
acetate butyrate; cellulose acetate phthalate; carboxylethyl
cellulose; cellulose triacetate; cellulose sulfate sodium salt;
polymers of acrylic acid; methacrylic acid; copolymers of
methacrylic acid; derivatives of methacrylic acid; poly(methyl
methacrylate); poly(ethyl methacrylate); poly(butylmethacrylate);
poly(isobutyl methacrylate); poly(hexylmethacrylate); poly(isodecyl
methacrylate); poly(lauryl methacrylate); poly(phenyl
methacrylate); poly(methyl acrylate); poly(isopropyl acrylate);
poly(isobutyl acrylate); poly(octadecyl acrylate); poly(butyric
acid); poly(valeric acid); poly(lactide-co-caprolactone);
copolymers of poly(lactide-co-caprolactone); blends of
poly(lactide-co-caprolactone); hydroxyethyl methacrylate (HEMA);
copolymers of HEMA with acrylate; copolymers of HEMA with
polymethylmethacrylate (PMMA); polyvinylpyrrolidone/vinyl acetate
copolymer (PVP/VA); acrylate polymers/copolymers; acrylate/carboxyl
polymers; acrylate hydroxyl and/or carboxyl copolymers;
polycarbonate-urethane polymers; silicone-urethane polymers; epoxy
polymers; cellulose nitrates; polytetramethylene ether glycol
urethane; polymethylmethacrylate-2-hydroxyethylmethacryl ate
copolymer; polyethylmethacrylate-2-hydroxyethylmethacrylate
copolymer; polypropylmethacrylate-2-hydroxyethylmethacrylate
copolymer; polybutylmethacrylate-2-hydroxyethylmethacrylate
copolymer; polymethylacrylate-2-hydroxyethylmethacrylate copolymer;
polyethylacrylate-2-hydroxyethylmethacrylate copolymer;
polypropylacrylate-2-hydroxymethacrylate copolymer;
polybutylacrylate-2-hydroxyethylmethacrylate copolymer;
copolymermethylvinylether maleicanhydride copolymer; poly
(2-hydroxyethyl methacrylate) acrylate polymer/copolymer; acrylate
carboxyl and/or hydroxyl copolymer; olefin acrylic acid copolymer;
ethylene acrylic acid copolymer; polyamide polymers/copolymers;
polyimide polymers/copolymers; ethylene vinylacetate copolymer;
polycarbonate urethane; silicone urethane; polyvinylpyridine
copolymers; polyether sulfones; polygalactin, poly-(isobutyl
cyanoacrylate), and poly(2-hydroxyethyl-L-glutamine); polydimethyl
siloxane; poly(caprolactones); poly(ortho esters); polyamines;
polyethers; polyesters; polycarbamates; polyureas; polyimides;
polysulfones; polyacetylenes; polyethyeneimines; polyisocyanates;
polyacrylates; polymethacrylates; polyacrylonitriles; polyarylates;
and combinations, copolymers and/or mixtures of two or more of any
of the foregoing. In some cases, the particle includes a
hydrophobic material and at least one bioactive agent. In certain
embodiments, the hydrophobic material is used instead of a polymer.
In other embodiments, the hydrophobic material is used in addition
to a polymer.
[0026] In some embodiments, the presently disclosed particles
contain a biodegradable polymer. The biodegradable polymer can
contain a synthetic polymer, although natural polymers also can be
used. The polymer can be, for example, poly(lactic-co-glycolic
acid) (PLGA), polystyrene or combinations thereof. The polystyrene
can, for example, be modified with carboxyl groups. Other examples
of biodegradable polymers include poly(hydroxy acid); poly(lactic
acid); poly(glycolic acid); poly(lactic acid-co-glycolic acid);
poly(lactide); poly(glycolide); poly(lactide-co-glycolide);
polyanhydrides; polyorthoesters; polyamides; polycarbonates;
polyalkylenes; polyethylene; polypropylene; polyalkylene glycols;
poly(ethylene glycol); polyalkylene oxides; poly(ethylene oxides);
polyalkylene terephthalates; poly(ethylene terephthalate);
polyvinyl alcohols; polyvinyl ethers; polyvinyl esters; polyvinyl
halides; poly(vinyl chloride); polyvinylpyrrolidone; polysiloxanes;
poly(vinyl alcohols); poly(vinyl acetate); polyurethanes;
co-polymers of polyurethanes; derivativized celluloses; alkyl
cellulose; hydroxyalkyl celluloses; cellulose ethers; cellulose
esters; nitro celluloses; methyl cellulose; ethyl cellulose;
hydroxypropyl cellulose; hydroxy-propyl methyl cellulose;
hydroxybutyl methyl cellulose; cellulose acetate; cellulose
propionate; cellulose acetate butyrate; cellulose acetate
phthalate; carboxylethyl cellulose; cellulose triacetate; cellulose
sulfate sodium salt; polymers of acrylic acid; methacrylic acid;
copolymers of methacrylic acid; derivatives of methacrylic acid;
poly(methyl methacrylate); poly(ethyl methacrylate);
poly(butylmethacrylate); poly(isobutyl methacrylate);
poly(hexylmethacrylate); poly(isodecyl methacrylate); poly(lauryl
methacrylate); poly(phenyl methacrylate); poly(methyl acrylate);
poly(isopropyl acrylate); poly(isobutyl acrylate); poly(octadecyl
acrylate); poly(butyric acid); poly(valeric acid);
poly(lactide-co-caprolactone); copolymers of
poly(lactide-co-caprolactone); blends of
poly(lactide-co-caprolactone); polygalactin; poly-(isobutyl
cyanoacrylate); poly(2-hydroxyethyl-L-glutam-nine); and
combinations, copolymers and/or mixtures of one or more of any of
the foregoing. Furthermore, as a person of ordinary skill in the
art would appreciate, some of the polymers listed above as
"biocompatible" can also be considered biodegradable, whether or
not they are included in the above listing of representative
biodegradable polymers. As used herein, "derivatives" include
polymers having substitutions, additions of chemical groups and
other modifications routinely made by those skilled in the art.
[0027] In some embodiments, the drug delivery systems contain a
particle with a coating on the surface, wherein the coating
molecules have hydrophilic regions and, optionally, hydrophobic
regions, wherein the coated particle causes less inflammation than
a similar, but uncoated particle, as measured by standard
protocols, for example upon injection into the anterior chamber of
a New Zealand white rabbit or a human.
[0028] The drug delivery system can also include a coating. The
coating can be disposed on the surface of the particle, for example
by bonding, adsorption or by complexation. The coating can also be
intermingled or dispersed within the particle as well as disposed
on the surface of the particle.
[0029] The coating can be, for example, polyethylene glycol,
polyvinyl alcohol (PVA), or similar substances. The coating can be,
for example, vitamin E-PEG 1 k or vitamin E-PEG 5 k or the like.
Vitamin E-PEG 5 k can help present a dense coating of PEG on the
surface of a particle. The coating can also include nonionic
surfactants such as those composed of polyaklyene oxides, e.g.,
polyoxyethylene (PEO), also referred to herein as polyethylene
glycol; or polyoxypropylene (PPO), also referred to herein as
polypropylene glycol (PPG), and can include co-polymers of more
than one alkylene oxide. The copolymers can be, for example, random
copolymers, block copolymers or graft copolymers. In some
embodiments, the coating includes a
polyoxyethylene-polyoxypropylene copolymer, e.g., block copolymers
of ethylene oxide and propylene oxide. (i.e., poloxamers). Examples
of poloxamers suitable for use in the coatings include, for
example, poloxamers 188, 237, 338 and 407. These poloxamers are
available under the trade name Pluronic.RTM. (available from BASF,
Mount Olive, N.J.) and correspond to Pluronic.RTM. F-68, F-87,
F-108 and F-127, respectively. Poloxamer 188 (corresponding to
Pluronic.RTM. F-68) is a block copolymer with an average molecular
mass of about 7,000 to about 10,000 Da, or about 8,000 to about
9,000 Da, or about 8,400 Da. Poloxamer 237 (corresponding to
Pluronic.RTM. F-87) is a block copolymer with an average molecular
mass of about 6,000 to about 9,000 Da, or about 6,500 to about
8,000 Da, or about 7,700 Da. Poloxamer 338 (corresponding to
Pluronic.RTM. F-108) is a block copolymer with an average molecular
mass of about 12,000 to about 18,000 Da, or about 13,000 to about
15,000 Da, or about 14,600 Da. Poloxamer 407 (corresponding to
Pluronic.RTM. F-127) is a polyoxyethylene-polyoxypropylene triblock
copolymer in a ratio of between about E.sub.101 P.sub.56 E.sub.101
to about E.sub.106 P.sub.70 E.sub.106, or about E.sub.101 P.sub.56
E.sub.101, or about E.sub.106 P.sub.70 E.sub.106, with an average
molecular mass of about 10,000 to about 15,000 Da, or about 12,000
to about 14,000 Da, or about 12,000 to about 13,000 Da, or about
12,600 Da. For example, the NF forms of poloxamers or Pluronic.RTM.
polymers can be used.
[0030] In some embodiments, the coating can be, for example
Pluronic.RTM. P103 or Pluronic.RTM. P105. Pluronic.RTM. P103 is a
block copolymer with an average molecular mass of about 3,000 Da to
about 6,000 Da, or about 4,000 Da to about 6,000 Da, or about 4,950
Da. Pluronic.RTM. P105 is a block copolymer with an average
molecular mass of about 5,000 Da to about 8,000 Da, or about 6,000
Da to about 7,000 Da, or about 6,500 Da.
[0031] In some embodiments, the coating can have an average
molecular weight of about 9,000 Da or greater, about 10,000 Da or
greater, about 11,000 Da or greater or about 12,000 Da or greater.
In exemplary embodiments, the coating can have an average molecular
weight of from about 10,000 to about 15,000 Da, or about 12,000 to
about 14,000 Da, or about 12,000 to about 13,000 Da, or about
12,600 Da. In some embodiments, the coating can be selected from
Pluronic.RTM. P103, P105, F-68, F-87, F-108 and F-127, from
Pluronic.RTM. P103, P105, F-87, F-108 and F-127, or from
Pluronic.RTM. P103, P105, F-108 and F-127, or from Pluronic.RTM.
P103, P105 and F-127. In some embodiments, the coating can be
Pluronic.RTM. F-127. In representative embodiments, the coating is
associated with the particles. For example, the coating can be
covalently attached to the particles. In representative
embodiments, the coating is polyethylene glycol, which is
covalently attached to the particle, yielding what is commonly
referred to as a PEGylated particle.
[0032] In some embodiments, the coating is non-covalently
associated with the particle. This association can be held together
by any force or mechanism of molecular interaction that permits two
substances to remain in substantially the same positions relative
to each other, including intermolecular forces, dipole-dipole
interactions, van der Waals forces, hydrophobic interactions,
electrostatic interactions and the like. In some embodiments, the
coating is adsorbed onto the particle. According to representative
embodiments, a non-covalently bound coating can be comprised of
portions or segments that promote association with the particle,
for example by electrostatic or van der Waals forces. In some
embodiments, the interaction is between a hydrophobic portion of
the coating and the particle. Embodiments include particle coating
combinations which, however attached to the particle, present a
hydrophilic region, e.g. a PEG rich region, to the environment
around the particle coating combination. The particle coating
combination can provide both a hydrophilic surface and an uncharged
or substantially neutrally-charged surface, which can be
biologically inert.
[0033] Suitable coatings for use according to the compositions and
methods disclosed herein can be made up of molecules having
hydrophobic regions as well as hydrophilic regions. Without wishing
to be bound by any particular theory, it is believed that the
hydrophobic regions of the coating molecules are able to form
adsorptive interactions with the surface of the particle, and thus
maintain a non-covalent association with it, while the hydrophilic
regions orient toward the surrounding, frequently aqueous,
environment. In some embodiments the hydrophilic regions are
characterized in that they avoid or minimize adhesive interactions
with substances in the surrounding environment. Suitable
hydrophobic regions in the coatings can include, for example, PPO,
vitamin E and the like, either alone or in combination with each
other or with other substances. Suitable hydrophilic regions in the
coatings can include, for example, PEG, heparin, polymers that form
hydrogels and the like, alone or in combination with each other or
with other substances.
[0034] Representative coatings according to the compositions and
methods disclosed herein can include molecules having, for example,
hydrophobic segments such as PPO segments with molecular weights of
at least about 1.8 kDa, or at least about 2 kDa, or at least about
2.5 kDa, or at least about 3 kDa, or at least about 3.5 kDa, or at
least about 4.0 kDa, or at least about 4.5 kDa, or at least about
5.0 kDa or more. In some embodiments, the coatings can have PPO
segments with molecular weights of from about from about 1.8 kDa to
about 10 kDa, or from about 2 kDa to about 5 kDa, or from about 2.5
kDa to about 4.5 kDa, or from about 2.5 kDa to about 3.5 kDa. In
some embodiments, at least about 10%, or at least about 25%, or at
least about 50%, or at least about 75%, or at least about 90%, or
at least about 95%, or at least about 99% or more of the
hydrophobic regions in these coatings have molecular weights within
these ranges. In some embodiments, the coatings are biologically
inert. Compounds that generate both a hydrophilic surface and an
uncharged or substantially neutrally-charged surface can be
biologically inert.
[0035] In some embodiments, the coating can include, for example,
one or more of the following: anionic proteins (e.g., bovine serum
albumin), surfactants (e.g., cationic surfactants such as for
example dimethyldioctadecyl-ammonium bromide), sugars or sugar
derivatives (e.g., cyclodextrin), nucleic acids, polymers (e.g.,
heparin), mucolytic agents, N-acetylcysteine, mugwort, bromelain,
papain, clerodendrum, acetylcysteine, bromhexine, carbocisteine,
eprazinone, mesna, ambroxol, sobrerol, domiodol, letosteine,
stepronin, tiopronin, gelsolin, thymosin .beta.4, dornase alfa,
neltenexine, erdosteine, various DNases including rhDNase, agar,
agarose, alginic acid, amylopectin, amylose, beta-glucan, callose,
carrageenan, cellodextrins, cellulin, cellulose, chitin, chitosan,
chrysolaminarin, curdlan, cyclodextrin, dextrin, ficoll, fructan,
fucoidan, galactomannan, gellan gum, glucan, glucomannan,
glycocalyx, glycogen, hemicellulose, hydroxyethyl starch, kefiran,
laminarin, mucilage, glycosaminoglycan, natural gum, paramylon,
pectin, polysaccharide peptide, schizophyllan, sialyl lewis x,
starch, starch gelatinization, sugammadex, xanthan gum, xyloglucan,
L-phosphatidylcholine (PC), 1,2-dipalmitoylphosphatidycholine
(DPPC), oleic acid, sorbitan trioleate, sorbitan monooleate,
sorbitan monolaurate, polyoxyethylene (20) sorbitan monolaurate,
polyoxyethylene (20) sorbitan monooleate, natural lecithin, oleyl
polyoxyethylene (2) ether, stearyl polyoxyethylene (2) ether,
polyoxyethylene (4) lauryl ether, block copolymers of oxyethylene
and oxypropylene, synthetic lecithin, diethylene glycol dioleate,
tetrahydrofurfuryl oleate, ethyl oleate, isopropyl myristate,
glyceryl monooleate, glyceryl monostearate, glyceryl
monoricinoleate, cetyl alcohol, stearyl alcohol, polyethylene
glycol 400, cetyl pyridinium chloride, benzalkonium chloride, olive
oil, glyceryl monolaurate, corn oil, cotton seed oil, sunflower
seed oil, lecithin, oleic acid, sorbitan trioleate, and
combinations of two or more of any of the foregoing.
[0036] The particle-coating combinations can be made up of any
combination of particle and coating substances disclosed or
suggested herein. Examples of such combinations include, for
example, polystyrene-PEG, or PLGA-Pluronic.RTM. F-127.
[0037] In some embodiments, the coating is associated with the
particle, either through covalent or non-covalent interactions with
the particle. Coatings that can be covalently bound to the particle
include, for example, PEG. PEG can be covalently bound to any
suitable polymer that can be included in the particle. An example
of a polymer that can be coated with PEG is polystyrene. Other
particles that can be PEGylated are known in the art.
[0038] The drug delivery system can include one or more therapeutic
agents. Any therapeutic agent can be used which is suitable to
administration in the drug delivery system disclosed herein, as
would be appreciated by a person of ordinary skill. Examples of
types of such therapeutic agents include anti-inflammatory drugs,
antimicrobial agents, anti-angiogenesis agents, immunosuppressants,
antibodies, steroids, chemotherapeutic agents, ocular
anti-hypertensive drugs and combinations thereof. Examples of
therapeutic agents that can be used in the drug delivery system
disclosed herein include acyclovir, amikacin, anecortane acetate,
anthracenedione, anthracycline, an azole, amphotericin B,
bevacizumab, camptothecin, cefuroxime, chloramphenicol,
chlorhexidine, chlorhexidine digluconate, clortrimazole, a
clotrimazole cephalosporin, corticosteroids, dexamethasone,
desamethazone, econazole, eftazidime, epipodophyllotoxin,
fluconazole, flucytosine, fluoropyrimidines, fluoroquinolines,
gatifloxacin, glycopeptides, imidazoles, itraconazole, ivermectin,
ketoconazole, levofloxacin, macrolides, miconazole, miconazole
nitrate, moxifloxacin, natamycin, neomycin, nystatin, ofloxacin,
polyhexamethylene biguanide, prednisolone, prednisolone acetate,
pegaptanib, platinum analogues, polymicin B, propamidine
isethionate, pyrimidine nucleoside, ranibizumab, squalamine
lactate, sulfonamides, triamcinolone, triamcinolone acetonide,
triazoles, vancomycin, anti-vascular endothelial growth factor
(VEGF) agents, VEGF antibodies, VEGF antibody fragments, vinca
alkaloid, timolol, betaxolol, travoprost, latanoprost, bimatoprost,
brimonidine, dorzolamide, acetazolamide, pilocarpine,
ciprofloxacin, azithromycin, gentamycin, tobramycin, cefazolin,
voriconazole, gancyclovir, cidofovir, foscarnet, diclofenac,
nepafenac, ketorolac, ibuprofen, indomethacin, fluoromethalone,
rimexolone, anecortave, cyclosporine, methotrexate, tacrolimus and
combinations thereof.
[0039] The drug delivery systems disclosed herein, which can
include one or more therapeutic agents, can be used to treat eye
disorders according to the methods disclosed herein. The drug
delivery system can be used to treat any eye disorder that, in the
judgment of a person of ordinary skill in the art, would be
effectively treated with any of the drug delivery systems disclosed
herein. Examples of eye disorders that may be treated according to
the compositions and methods disclosed herein include amoebic
keratitis, fungal keratitis, bacterial keratitis, viral keratitis,
onchorcercal keratitis, bacterial keratoconjunctivitis, viral
keratoconjunctivitis, corneal dystrophic diseases, Fuchs'
endothelial dystrophy, Sjogren's syndrome, Stevens-Johnson
syndrome, autoimmune dry eye diseases, environmental dry eye
diseases, corneal neovascularization diseases, post-corneal
transplant rejection prophylaxis and treatment, autoimmune uveitis,
infectious uveitis, anterior uveitis, posterior uveitis (including
toxoplasmosis), pan-uveitis, an inflammatory disease of the
vitreous or retina, endophthalmitis prophylaxis and treatment,
macular edema, macular degeneration, age related macular
degeneration, proliferative and non-proliferative diabetic
retinopathy, hypertensive retinopathy, an autoimmune disease of the
retina, primary and metastatic intraocular melanoma, other
intraocular metastatic tumors, open angle glaucoma, closed angle
glaucoma, pigmentary glaucoma and combinations thereof.
[0040] According to the methods disclosed herein, the drug delivery
system can be administered into an eye compartment of a patient
with an eye disorder. The drug delivery system can be administered
to any eye compartment that is susceptible to an eye disorder
treatable with the compositions and methods disclosed herein.
Examples of such eye compartments include the vitreous chamber,
subretinal space, subchoroidal space, the episclera, the
conjunctiva, the sclera, the anterior chamber, and the cornea and
compartments therein (e.g., subepithelial, intrastromal,
endothelial).
[0041] The drug delivery system can be administered via any route
which is effective to deliver an effective amount of the
therapeutic agent to the eye compartment to be treated. For
example, the drug delivery system can be injected into the eye
compartment to be treated, such as, for example, the vitreous
chamber, subretinal space, subchoroidal space, the episclera, the
conjunctiva, the sclera or the anterior chamber, and the cornea and
compartments therein (e.g., subepithelial, intrastromal,
endothelial).
[0042] The drug delivery systems disclosed herein provide sustained
release of a therapeutic agent over a period of time. For example,
after administration of the drug delivery system, the therapeutic
agent can be released for at least about 6 hours, at least about 12
hours, at least about 1 day, at least about 2 days, at least about
3 days, at least about one week, at least about 2 weeks, at least
about 3 weeks, at least about 4 weeks, at least about 5 weeks, at
least about 6 weeks, at least about 7 weeks, at least about 2
months, at least about 3 months, at least about 6 months, at least
about 9 months, at least about 1 year or more. Furthermore,
according to the compositions and methods disclosed herein,
administration of the drug delivery systems to the patient causes
less inflammation or IOP over time than if other drug delivery
systems are administered. Notwithstanding the foregoing, there may
be some initial inflammation shortly after administration, even
with the drug delivery system disclosed herein. However, a
reduction of inflammation or IOP can be observed after about 2 days
post-administration, or after about 5 days post-administration.
Inflammation or IOP is reduced over time, even with administration
of conventional or previously available drug delivery systems.
However, the reduction or avoidance of inflammation or IOP when
using methods and compositions disclosed herein is persistent and
can continue to be observed for up to 30 days, up to 20 days, up to
15 days, or up to 10 days post-administration. The reduction or
avoidance of inflammation or IOP can continue for at least about 10
days, at least about 15 days, at least about 20 days, or at least
about 30 days post-administration.
[0043] In some embodiments, the drug delivery systems disclosed
herein when administered to the vitreous chamber, the sclera, the
anterior chamber or other eye compartment of a patient, achieve
reduced or decreased inflammation, and thus, for example, reduced
intraocular pressure (TOP) over that which would be brought about
if, for example, an uncoated polymer particle, for example a
particle otherwise similar to the coated particle, were
administered to same eye compartment in the patient. Furthermore,
drug delivery systems including particles and coatings according to
the compositions and methods disclosed herein can reduce or avoid
an increase in IOP over that which would be observed if uncoated
particles of similar size were administered. Accordingly, the
particle size threshold for inducing or increasing IOP can be
higher for coated particles than it would be for uncoated
particles. As a result, it may be possible to use larger particles
for administration into an eye compartment, for example into the
AC, if such particles are coated according to the compositions and
methods disclosed herein. In some embodiments, the drug delivery
systems disclosed herein provide the advantage of avoiding or
reducing aggregation of particles after administration.
[0044] Inflammation and TOP can be measured after administration of
the compositions disclosed herein by methods known in the art. For
example, a Reichert Tono-Pen contact tonometer can be used to
assess the IOP, and changes in IOP, in any eye compartment
disclosed herein, for example the AC. The subjects, for example
animals, can be evaluated on several post-injection days, for
example at 1, 7, 14 and 30 days post-injection using the same
evaluation procedure on each day. One or more measurements, for
example about five, can be obtained for each subject at each time
point. When measuring IOP according to methods known in the art,
for example the method described above, IOP is shown to be reduced
by, for example, at least about 10%, or at least about 30%, or at
least about 50% over what is observed when a drug delivery system
using an uncoated particle, for example a particle that is
otherwise similar to the coated particle, is administered to the
patient. To measure inflammation, Slit-lamp biomicroscopy can be
performed to examine any eye compartment disclosed herein, for
example, the AC, for signs of inflammation. The examination can
involve observation of criteria such as the presence of cells,
flare and fibrin. The subjects can be evaluated on several
post-injection days, for example at 1, 7, 14 and 30 days
post-injection using the same evaluation procedure on each day.
After general and/or local anesthesia is achieved, each subject can
be examined for gross abnormalities. The exams can be performed by
the same trained ophthalmologist, and the ophthalmologist can be
blinded to the assignment of the treatment and control subjects.
Quantification of inflammation of an eye compartment such as the AC
can be performed using a modified version of the Standard Uveitis
Nomenclature clinical grading scheme, as detailed more fully in the
examples. When measuring inflammation according to methods known in
the art, for example the method described above, inflammation is
shown to be reduced by, for example, at least about 10%, or at
least about 30%, or at least about 50% over what is observed when a
drug delivery system using an uncoated particle, for example a
particle that is otherwise similar to the coated particle, is
administered to the patient. When comparing an IOP or inflammation
measurement obtained after administration of a coated particle
versus an IOP or inflammation measurement obtained for an uncoated
particle, the measurements compared can, and frequently should, be
taken at similar time points post injection. For example, an IOP
measurement for a coated particle taken 7 days post-injection is
generally compared with an IOP measurement for an uncoated particle
taken 7 days post-injection.
[0045] A further advantage of certain embodiments of the drug
delivery systems disclosed herein is that they can be composed of
generally recognized as safe (GRAS) materials, without the
formation of new chemical entities (NCEs). Avoidance of NCE
formation can be an advantage because NCEs can be subject to a
lengthy and expensive regulatory review process before they are
permitted to be marketed.
[0046] As described in detail in the Examples, the particle
compositions can be retained within an eye compartment, including
for example the stroma, the anterior chamber or the vitreous
chamber for periods of time greater than those observed with
free-standing drugs. Furthermore, coated particle compositions can
exhibit increased retention over uncoated particle compositions.
This effect is seen in particles with covalently-attached coatings,
for example PEG-coated particles, as well as in particles with
non-covalently associated coatings, of which Pluronic.RTM.
PF-127-coated particles are representative, and indeed the extent
of the effect can be very similar for covalently-attached and
non-covalently associated coatings (see FIG. 1). FIG. 1 also
demonstrates that this effect is also seen in particle compositions
made with PLGA particles as well as those made with polystyrene
particles. Furthermore, the increased retention is observed with
polystyrene particles covalently coated with PEG coating as well as
in PLGA particles with non-covalently associated Pluronic.RTM.
PF-127 coating. Accordingly, where increased retention is
demonstrated for one type of particle composition, for example,
covalently-PEGylated polystyrene particles--one of ordinary skill
in the art may expect that similar results would be obtained for
other types of particle compositions, e.g., PLGA particles
non-covalently coated with a poloxamer. For instance, as shown in
the examples, PEGylated polystyrene particles behave similarly to
and can serve as a model for PLGA particles with non-covalently
associated coatings such as Pluronic.RTM. PF-127 coating. These
findings are consistent with the art usage of polystyrene particles
as models for other biocompatible particles and polymers.
[0047] Topically-administered medications to the eye often exhibit
a poor ability to penetrate the corneal stroma. Further,
free-standing drugs, when injected into the corneal stroma, are
cleared rapidly by diffusion, thereby limiting the amount of time
the medication remains at therapeutic concentrations at the site of
the injection. In some embodiments, the presently disclosed subject
matter demonstrates, for example, that intrastromally injected
particle compositions can be retained with the corneal stroma for
periods of time greater than free-standing drugs. For example,
200-nm and 1-.mu.m latex particles injected intrastromally into
living rabbits exhibited approximately 20% retention after two
weeks. Uncoated 200-nm latex particles, however, caused substantial
fibrin aggregation suggestive of inflammation after intraocular
injection in living rabbits. By varying size and surface chemistry
in accordance with the principles set forth herein, particles can
be engineered to reduce or avoid corneal inflammation and
edema.
[0048] In some embodiments, the presently disclosed subject matter
includes delivery systems for intrastromal injection of medications
that are combined with the particles disclosed herein. Medications
can include, but are not limited to, anti-inflammatory agents,
antimicrobial agents, anti-angiogenesis agents, immunosuppressants,
and/or combinations thereof. Such combinations of medications can
allow for the treatment of conditions that require more than one
medication. More particularly, in some embodiments, the presently
disclosed subject matter includes particle compositions containing
anti-inflammatory agents for treating and/or preventing
inflammatory processes of the cornea. Some embodiments of the
presently disclosed subject matter include particle compositions
containing immunosuppressant agents for preventing graft rejection
after corneal transplantation.
[0049] In some embodiments, the presently disclosed subject matter
includes particles coated with and/or otherwise carrying
antibodies, wherein the antibodies serve as a therapeutic agent and
can be released over time. In some embodiments, the presently
disclosed subject matter includes particles combining a therapeutic
antibody coating with other therapeutic agents, e.g., one or more
medications.
[0050] Further, the presently disclosed subject matter includes
pharmaceutical formulations including solutions of the presently
disclosed particle compositions, wherein the particles are combined
with antibacterial agents, antifungal agents, anti-amoebic agents,
antiviral agents, and combinations thereof for treating and/or
preventing infectious processes of the cornea. The presently
disclosed subject matter also includes pharmaceutical formulations
including solutions of the presently disclosed particle
compositions containing and/or coated with anti-angiogenesis agents
(such as, for example, antibodies) for use in chronic inflammatory
diseases of the cornea and/or other diseases that can lead to
corneal neovascularization. Combinations of the above-mentioned
pharmaceutical formulations also are contemplated by the presently
disclosed subject matter.
[0051] In a representative embodiment, the presently disclosed
subject matter provides methods for treating keratitis, i.e.,
inflammations of the cornea, by injecting the presently disclosed
particle compositions containing one or more therapeutic agents
into the corneal stroma. Conditions treated by the presently
disclosed methods include, but are not limited to, amoebic
keratitis, fungal keratitis, bacterial keratitis, viral keratitis,
and onchorcercal keratitis.
[0052] Ameobic keratitis can be caused by acanthamoeba and can be
treated by administering to the corneal stroma of a subject in need
of treatment thereof the presently disclosed particle compositions
containing one or more anti-amoebic agents. Any anti-amoebic agent
known in the art can be combined with the presently disclosed
particle compositions. Representative, anti-amoebic agents include,
but are not limited to, polyhexamethylene biguanide (PHMB),
propamidine isethionate, miconazole nitrate, neomycin,
chlorhexidine digluconate, polymicin B, clortrimazole, and
combinations thereof.
[0053] Fungal keratitis can be caused by, for example, aspergillus
fumigates, fusarium, and/or yeasts, such as candida, and can be
treated by administering to the corneal stroma of a subject in need
of treatment thereof the presently disclosed particle compositions
containing one or more anti-fungal agents. Any anti-fungal agent
known in the art can be combined with the presently disclosed
particle compositions. Representative, anti-fungal agents include,
but are not limited to, natamycin, nystatin, amphotericin B,
chlorhexidine, fluorinated pyrimidines, such as flucytosine,
azoles, such as imidazoles and triazoles, including, but not
limited to, ketoconazole, miconazole, itraconazole, fluconazole,
econazole, and clotrimazole, and combinations thereof.
[0054] Bacterial keratitis can be caused, for example, by
Streptococcus, Pseudomonas, Enterobacteriaceae (including
Klebsiella, Enterobacter, Serratia, and Proteus), and
Staphylococcus species. Such infections can be treated by
administering to the corneal stroma of a subject in need of
treatment thereof the presently disclosed particle compositions
containing one or more anti-bacterial agents. Any anti-bacterial
agent known in the art can be combined with the presently disclosed
particle compositions. Representative, anti-bacterial agents
include, but are not limited to, cephalosporins, macrolides,
glycopeptides, sulfonamides, chloramphenicol, fluoroquinolines,
including, but not limited to, levofloxacin, gatifloxacin,
moxifloxacin, and ofloxacin, and combinations thereof.
[0055] Further, up to 20% of cases of fungal keratitis
(particularly candidiasis) can be complicated by bacterial
co-infection. Thus, in some embodiments, the presently disclosed
methods include combination therapies involving administering to
the corneal stroma of a subject in need of treatment thereof the
presently disclosed particle compositions containing one or more
anti-fungal agents and one or more anti-bacterial agents.
[0056] Viral keratitis can, for example, be caused by a herpes
simplex virus and can be treated by administering to the corneal
stroma of a subject in need of treatment thereof the presently
disclosed particle compositions containing one or more anti-viral
agents. Any anti-viral agent known in the art can be combined with
the presently disclosed particle compositions. A representative
anti-viral agent includes, but is not limited to, acyclovir.
[0057] Onchoceral keratitis, also referred to as "River Blindness,"
is caused by the nematode Onchocerca volvulus and can be treated by
administering to the corneal stroma of a subject in need of
treatment thereof the presently disclosed particle compositions
containing one or more anti-parasitic agents. Any anti-parasitic
agent known in the art can be combined with the presently disclosed
particle compositions. A representative anti-parasitic agent
includes, but is not limited to, ivermectin.
[0058] Further, representative embodiments of the presently
disclosed methods include a method for reversing or preventing
graft rejection following corneal transplantation, the method
involving administering to the corneal stroma of a subject in need
of treatment thereof the presently disclosed particle compositions
containing one or more immunosuppressive agents. Any
immunospressive agent known in the art can be combined with the
presently disclosed particle compositions. Representative
immunosuppressive agents include, but are not limited to,
corticosteroids, such as dexamethasone and prednisolone
acetate.
[0059] In some embodiments, the presently disclosed subject matter
demonstrates that, rather than injecting free-standing drugs into
the anterior chamber (AC) of an eye, particles injected into the AC
can be retained for at least several weeks. The time period spans
the entire duration of typical post-operative treatment. By
delivering medications combined with the presently disclosed
particle compositions, the limitations of topical and intracameral
free drug injection can be eliminated. This approach was limited in
the past by particle-mediated increase in intraocular pressure
(TOP) and inflammation responses. The presently disclosed subject
matter overcomes these limitations by suitably modifying particle
size and/or surface chemistry.
[0060] For example, the presently disclosed subject matter
demonstrates that particles injected directly into the AC of an eye
can be retained for long periods of time, thereby providing an
effective vehicle for sustained ocular drug delivery. For example,
the presently disclosed subject matter demonstrates that 200-nm
latex particles, covalently coated with a representative coating
such as, for example, poly(ethylene glycol), can be retained in the
eyes of living rabbits for at least four weeks with greater than
30% retention. Based on experiments disclosed herein, other coated
particles described herein, for example PLGA non-covalently coated
with poloxamer, can bring about similar outcomes. In contrast, free
drugs injected into the AC are cleared rapidly, for example, at the
same rate as the aqueous humor turnover.
[0061] Further, uncoated 200-nm latex particles caused substantial
fibrin aggregation in the AC of living rabbits. The presently
disclosed subject matter demonstrates that by suitably modifying
size and/or surface chemistry, particles can be engineered to avoid
causing an increase in IOP and inflammation in the AC. For example,
the presently disclosed subject matter demonstrates that 200-nm
latex particles, covalently coated with PEG, did not induce an
increase in IOP after injection into the AC of a living rabbit.
Based on experiments disclosed herein, other coated particles
described herein, for example PLGA non-covalently coated with
poloxamer, can bring about similar outcomes.
[0062] In some embodiments, the presently disclosed subject matter
includes medications for intracameral injection combined within
particles including, but not limited to, anti-inflammatory drugs,
antimicrobials, anti-angiogenesis agents, immunosuppressants,
and/or combinations thereof. Such combinations of medications can
allow for the treatment of conditions that require more than one
medication. For example, the presently disclosed subject matter
includes particle compositions containing anti-inflammatory agents
alone or included with anti-angiogenesis agents for treating
chronic corneal and/or anterior chamber inflammatory processes. In
some embodiments, the presently disclosed subject matter provides
particle compositions containing immunosuppressant agents either
alone or in combination with anti-inflammatory agents and/or
antimicrobial agents for use in post-corneal transplant cases.
[0063] Further, the presently disclosed subject matter includes
pharmaceutical formulations containing solutions of the presently
disclosed particle compositions, wherein the particle compositions
contain anti-inflammatory and/or antimicrobial agents for injection
after cataract extraction or other ophthalmic surgeries. The
presently disclosed subject matter also includes pharmaceutical
formulations of solutions of the presently disclosed particle
compositions, wherein the particle compositions contain
antibacterial, antifungal, amoebicidal, antiviral agents, or
combinations thereof, for treating chronic infectious processes of
the cornea and/or the anterior chamber. Combinations of the
above-mentioned pharmaceutical formulations also are contemplated
by the presently disclosed subject matter.
[0064] For example, the presently disclosed subject matter provides
a method for intracameral administration of the presently disclosed
particle compositions containing one or more therapeutic agents to
an anterior chamber of an eye of a subject in need of treatment
thereof. Depending on the condition of the subject, the therapeutic
agent can be selected from the group consisting of an antibiotic,
e.g., vancomycin, amikacin, eftazidime, cefuroxime, moxifloxacin,
or a steroid, e.g., triamcinolone, dexamethasone, and prednisolone.
The presently disclosed particle compositions can be administered
prophylactically to prevent or reduce the occurrence of a
post-operative infection of the anterior chamber or can be
administered therapeutically to treat an infection of the anterior
chamber, e.g., endophthalmitis.
[0065] In some embodiments, the presently disclosed particle
compositions can provide an effective vehicle for sustained drug
delivery directly to the retina. For example, the presently
disclosed subject matter demonstrates that 200-nm latex particles,
coated with a representative coating such as, for example
poly(ethylene glycol) covalently bound to the particles, can be
retained in the eyes of living rabbits for more than one month with
no significant clearance and for over two months with only minimal
clearance.
[0066] Further, the presently disclosed subject matter shows that
uncoated 200-nm latex particles caused substantial fibrin
aggregation suggestive of inflammation after intraocular injection
in living rabbits. Also, uncoated 200-nm latex particles were found
to cause visible vitreous opacities after intravitreal injection in
living rabbits. By suitably modifying size and/or surface
chemistry, the presently disclosed particle compositions can be
engineered to avoid visual obstruction and inflammation in the
vitreous chamber.
[0067] Other sustained release drug systems, when injected
subconjunctivally, afford limited intraocular bioavailability of
delivered medications due to barriers to drug penetration. Further,
free drugs, when injected into the vitreous require multiple
injections per year due to drug metabolism and clearance. In
contrast, the presently disclosed particle compositions, when
injected into the vitreous, can be retained for long periods of
time.
[0068] In some embodiments, the presently disclosed subject matter
includes medications combined with particles, wherein the
medications include, but are not limited to, anti-inflammatory
drugs, antimicrobials, anti-angiogenesis agents,
immunosuppressants, anti-neoplastic agents and/or combinations
thereof. Such combinations allow for the treatment of conditions
that require more than one medication.
[0069] More particularly, the presently disclosed subject matter
includes particle compositions containing anti-inflammatory agents
for the treatment and/or prevention of macular edema and/or other
inflammatory diseases of the retina. In some embodiments, the
presently disclosed subject matter includes particle compositions
containing anti-neoplastic agents for treatment of intraocular
cancers. In yet other embodiments, the presently disclosed subject
matter includes particle compositions containing immunosuppressant
agents for the treatment of autoimmune and/or inflammatory diseases
of the retina.
[0070] In other embodiments, the presently disclosed subject matter
includes particles coated with and/or otherwise carrying
antibodies, wherein the antibodies are a therapeutic agent and can
be released over time. In yet other embodiments, the presently
disclosed subject matter includes particles combining a therapeutic
antibody coating with other therapeutic agents, e.g., one or more
medications.
[0071] The presently disclosed subject matter also includes
pharmaceutical formulations for intravitreal injection containing
solutions of the presently disclosed particle compositions
containing and/or coated with anti-angiogenesis agents (antibodies)
for use in degenerative diseases of the retina and/or proliferative
retinopathy and/or other vascular diseases of the retina. Some
representative embodiments include pharmaceutical formulations
containing solutions of particle compositions containing
anti-inflammatory and/or antimicrobial agents for the prevention
and/or treatment of post-surgical complications and/or infections
after vitreoretinal operations. Further, pharmaceutical
formulations containing solutions containing antibacterial and/or
antifungal and/or anti-amoebic and/or antiviral agents for
treatment of infectious processes of the vitreous and/or retina,
including, but not limited to, endophthalmitis also are disclosed.
Combinations of the above-mentioned pharmaceutical formulations
also are contemplated by the presently disclosed subject
matter.
[0072] For example, the presently disclosed subject matter provides
a method for treating age-related macular degeneration in a subject
in need of treatment thereof, the method involving administering
via intravitreal injection to a vitreous chamber and/or retina of
an eye of the subject the presently disclosed particle compositions
containing one or more therapeutic agents selected from the group
consisting of anti-vascular endothelial growth factor (VEGF)
agents, including, but not limited to pegaptanib, bevacizumab,
anecortane acetate, squalamine lactate, ranibizumab, or
corticosteroids, including, but not limited to, triamcinolone
acetonide.
[0073] In other embodiments, the presently disclosed subject matter
provides a method for treating proliferative diabetic retinopathy
in a subject in need of treatment thereof, the method involving
administering via intravitreal injection to a vitreous chamber
and/or retina of an eye of the subject the presently disclosed
particle compositions containing one or more therapeutic agents
selected from the group consisting of steroids, such as
triamcinolone acetonide, ovine hyaluronidase, VEGF antibodies, such
as bevacizumab, or VEGF antibody fragments, such as ranibizumab,
and combinations thereof.
[0074] In yet other embodiments, the presently disclosed subject
matter provides a method for treating ocular cancer in a subject in
need of treatment thereof, the method involving administering via
intravitreal injection to a vitreous chamber and/or retina of an
eye of a subject the presently disclosed particle compositions
containing one or more anti-neoplastic agents. Representative
anti-neoplastic agent include, but are not limited to,
fluoropyrimidine, pyrimidine nucleoside, platinum analogue,
anthracycline, anthracenedione, epipodophyllotoxin, camptothecin,
vinca alkaloid, and combinations thereof.
[0075] The particles according to the compositions and methods
disclosed herein can be of any size that is consistent with
effective treatment of the eye disorders disclosed herein, in the
judgment of a person of ordinary skill in the art. For example,
particles of any size can be used provided they do not obstruct the
flow of intraocular fluids into and/or out of the eye compartment
into which the particle composition is administered, which could
increase inflammation or IOP. Particles having a diameter of, for
example, from about 1 nm to about 100,000 nm, or from about 1 nm to
about 50,000 nm, or from about 50 nm to about 50,000 nm, or from
about 1 nm to about 30,000 nm, or from about 1 nm to about 10,000
nm, or from about 1 nm to about 1,000 nm, can be used according to
the compositions and methods disclosed herein. Particles having a
diameter of, for example, at least about 1 nm, at least about 10
nm, at least about 50 nm, at least about 100 nm, at least about 300
nm, at least about 500 nm or more can be used. Particles having a
diameter of less than about 100,000 nm, or less than about 50,000
nm, or less than about 25,000 nm, or less than about 10,000 nm, or
less than about 6,000 nm, or less than about 5,000 nm, or less than
about 2,000 nm, or less than about 1,000 nm, or less than about 800
nm, or less than about 600 nm, or less than about 500 nm, or less
than about 200 nm can be used. Particles of different diameters may
be appropriate for administration to different eye compartments.
For example, particles for intravitreal administration can have a
diameter of at least about 1 nm, or from about 1 nm to about 50,000
nm, or any other diameter range disclosed herein. Particles for
administration into the anterior chamber can have a diameter of,
for example, from about 1 nm to about 7,000 nm, or from about 10 nm
to about 6,000 nm, or from about 100 nm to about 2,000 nm, or from
about 600 to about 1000 nm; or less than about 6,000 nm, or less
than about 2,000 nm, or less than about 1,000 nm, or less than
about 800 nm.
[0076] In some embodiments, the drug delivery system can include,
for example, (i) a substrate; and (ii) a coating associated with
the substrate. As used herein, a "substrate" is any substance,
device or apparatus that can be coated according to the
compositions and methods disclosed herein and thereafter
administered to a patient. A substrate can be, for example, a
medical device or an implant, or a particle as described herein.
The substrate can be of any size that is consistent with effective
delivery of a therapeutic agent to a patient, in the judgment of a
person of ordinary skill in light of the compositions and methods
disclosed herein. A substrate can have a diameter of, for example,
at least about 1 nm, or at least about 1 micron, or at least about
1 mm, or at least about 10 mm; or from about 1 nm to about 10 mm,
or from about 1 nm to about 1 mm, or from about 1 nm to about 100
microns, or from about 1 nm to about 10 microns, or from about 1 nm
to about 1 micron. A substrate can be, for example, suitable for
administration to a patient by any means known in the art, for
example by injection or other form of systemic administration,
whether rectally, transmucosally, transnasally, intestinally,
parenterally, intramuscularly, subcutaneously, intramedullarily,
intrathecally, intraventricularly, intravenously,
intraperitoneally, intranasally, intraocularly, or transurethrally;
or topically; or via implantation into any region of the body of a
patient. In some embodiments, the coating presents a hydrophilic
region to the environment around the substrate. The drug delivery
system can include, for example, a therapeutically effective amount
of a therapeutic agent. The drug delivery system can, for example,
bring about reduced inflammation when administered to the patient
than if a drug delivery system comprising an uncoated particle were
administered to the patient. As would be appreciated by a person of
ordinary skill, the compositions and methods disclosed herein can
be applied to drug delivery systems of any size range, up to and
including of a size suitable for implants, including for example,
intraocular implants, or the like.
[0077] The drug delivery system can also include, for example, (i)
a substrate; (ii) a coating associated with the substrate, wherein
the coating presents a hydrophilic region to the environment around
the substrate; and (iii) a therapeutically effective amount of a
therapeutic agent. In some embodiments, the drug delivery system is
suitable for administration to a patient. The drug delivery system
can, for example, bring about reduced inflammation when
administered to the patient than if a drug delivery system
comprising an uncoated substrate were administered to the
patient.
[0078] In some embodiments the particles of the compositions and
methods disclosed herein are nanoparticles. As used herein, the
term "nanoparticle" refers to a particle having at least one
dimension in the range of about 1 nm to about 1000 nm, including
any integer value between 1 nm and 1000 nm (including about 1, 2,
5, 10, 20, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 400, 500,
600, 700, 800, 900 and 1000 nm and all integers and fractional
integers in between). In some embodiments, the nanoparticle has at
least one dimension, e.g., a diameter, of about 100 nm. In some
embodiments, the nanoparticle has a diameter of about 200 nm. In
other embodiments, the nanoparticle has a diameter of about 500 nm.
In yet other embodiments, the nanoparticle has a diameter of about
1000 nm (1 gm). In such embodiments, the particle also can be
referred to as a "microparticle." As used herein, "microparticle"
refers to a particle having at least one dimension in the range of
about 1 .mu.m to about 100 .mu.m, including any integer value
between 1 .mu.m and 100 gm (including about 1, 2, 5, 10, 20, 30 40,
50, 60, 70, 80, 90 and 100 .mu.m and all integers and fractional
integers in between). Exemplary microparticles have a diameter of
less than about 100 microns, less than about 50 microns, less than
about 10 microns, less than about 5 microns, or less than about 3
microns, or less than about 2 microns. The term "particle" as used
herein is meant to include nanoparticles and microparticles.
[0079] It will be appreciated by one of ordinary skill in the art
that particles suitable for use with the presently disclosed
methods can exist in a variety of shapes, including, but not
limited to, spheroids, rods, disks, pyramids, cubes, cylinders,
nanohelixes, nanosprings, nanorings, rod-shaped particles,
arrow-shaped particles, teardrop-shaped particles, tetrapod-shaped
particles, prism-shaped particles, and a plurality of other
geometric and non-geometric shapes. In some embodiments, the
presently disclosed particles have a spherical shape.
[0080] In some embodiments, the presently disclosed particles
include polystyrene particles. For example, the presently disclosed
particles include carboxyl-modified polystyrene particles. The
presently disclosed particles in some embodiments can be tagged,
e.g., with a fluorescent molecule, to enable them to be detected or
monitored when administered to a subject. For example, in some
embodiments, the particles include yellow-green fluorescent
carboxyl-modified polystyrene particles (Molecular Probes, Eugene,
Oreg.).
[0081] Further, in some embodiments, the presently disclosed
particles can be surface modified, e.g., by covalently attaching
PEG, often referred to as being PEGylated. Such particles can be
prepared as disclosed in Lai et al., "Rapid transport of large
polymeric nanoparticles in fresh undiluted human mucus," Proc.
Natl. Acad. Sci. U.S.A., 104(5):1482-1487 (2007) and Suh et al.,
"PEGylation of nanoparticles improves their cytoplasmic transport,"
Int. J. Nanomed., 2(4), 735-741 (2007).
[0082] For example, one 100- to 500-nm yellow-green fluorescent,
carboxyl-modified polystyrene (PS) particles (Molecular Probes,
Eugene, Oreg.) can be dialyzed extensively against PBS (300 kDa,
Spectrum Lab, Rancho Dominguez, Calif.). Polyethylene glycol can be
covalently attached to the particles via carboxyl-amine reaction.
Briefly, diamine PEG (molecular mass >2,000 Da, e.g., 3,400 Da;
Nektar Therapeutics, San Carlos, Calif.) can be dissolved in 50 mM
2-(N-morpholino)ethanesulfonic acid (MES) buffer (Sigma, St. Louis,
Mo.) at pH 6. PEG can be added to different sized nondialyzed
particles to yield final concentrations of 3:1 PEG:COOH and 1%
solids/mL. After 15 minutes,
1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (Sigma, St. Louis,
Mo.) can be added to a final concentration of 4 mg/mL, pH adjusted
to 6.5, and incubated on an orbital shaker for 2 hours at room
temperature. To quench the reaction, glycine (J.T. Baker,
Phillipsburg, N.J.) can be added to a final concentration of 100
mM. The solution can be incubated for 30 minutes at room
temperature and subsequently dialyzed extensively against PBS in a
300,000 kDa MWCO Float-a-lyzer (Spectrum Laboratories, Rancho
Dominguez, Calif.). Unmodified particles were dialyzed similarly to
remove all traces of sodium azide originally added by the
manufacturer.
[0083] Size and .xi.-potential can be determined by dynamic light
scattering and laser Doppler anemometry, respectively, using, for
example, a Zetasizer 3000 (Malvern Instruments, Southborough,
Mass.). Size measurements can be performed, for example, at
25.degree. C. at a scattering angle of 90.degree.. Samples can be
further diluted in double-distilled water. Representative
characteristics of particles prepared by the method of Lai et al.
are summarized in Table 1.
TABLE-US-00001 TABLE 1 Representative Characteristics of COOH-- and
PEG-Modified PS Particles Nominal Size Diameter .xi.-potential (nm)
Surface Chemistry (nm) (mV) 100 COOH 109.2 .+-. 3.1 -41.0 .+-. 1.9
100 PEG 122.4 .+-. 5.2 -4.4 .+-. 1.1 200 COOH 216.6 .+-. 4.5 -58.8
.+-. 4.2 200 PEG 232.3 .+-. 6.8 -2.1 .+-. 0.3 500 COOH 515.0 .+-.
7.2 -61.0 .+-. 0.5 500 PEG 529.1 .+-. 8.1 -5.6 .+-. 0.4
[0084] In certain embodiments, the particles can be combined with
an active ingredient, e.g., a drug, medication, or therapeutic
agent. Active ingredients include, but are not limited to, any
component, compound, or small molecule that can be used to bring
about a desired effect, e.g., a therapeutic effect. For example, a
desired effect can include the diagnosis, cure, mitigation,
treatment, or prevention of a disease or condition.
[0085] The active ingredient can be adsorbed, encapsulated,
entangled, embedded, incorporated, bound to the surface, or
otherwise associated with the particle. As used herein, "combined"
encompasses adsorbed, encapsulated, associated, entangled,
embedded, incorporated, bound to the surface, or any other means
for holding two substances or items together. As provided
hereinabove, in some embodiments the presently disclosed particles
can include a functional group, e.g., a carboxyl group. Other
functional groups include, but are not limited to, a sulhydryl,
hydroxyl, and/or amino group. The functional groups can be
available, for example, for drug binding (covalent or
electrostatic) or for other desired purposes within the scope of
the presently disclosed subject matter.
[0086] The subject treated by the presently disclosed methods in
their many embodiments is desirably a human subject, although it is
to be understood that the methods described herein are effective
with respect to all vertebrate species, which are intended to be
included in the term "subject." Accordingly, a "subject" can
include a human subject for medical purposes, such as for the
treatment of an existing condition or disease or the prophylactic
treatment for preventing the onset of a condition or disease, or an
animal subject for medical, veterinary purposes, or developmental
purposes. Suitable animal subjects include mammals including, but
not limited to, primates, e.g., humans, monkeys, apes, and the
like; bovines, e.g., cattle, oxen, and the like; ovines, e.g.,
sheep and the like; caprines, e.g., goats and the like; porcines,
e.g., pigs, hogs, and the like; equines, e.g., horses, donkeys,
zebras, and the like; felines, including wild and domestic cats;
canines, including dogs; lagomorphs, including rabbits, hares, and
the like; and rodents, including mice, rats, and the like. In some
embodiments, the subject is a human including, but not limited to,
fetal, neonatal, infant, juvenile, and adult subjects. Further, a
"subject" can include a patient afflicted with or suspected of
being afflicted with a condition or disease. Thus, the terms
"subject" and "patient" are used interchangeably herein.
[0087] The terms "treat" or "treating," and grammatical derivatives
thereof, as used herein refer to any type of treatment that imparts
a benefit to a subject afflicted with a disease or illness,
including any measurable improvement in the condition of the
subject, reducing a symptom of the condition, inhibiting an
underlying cause or mechanism related to the condition, delaying
the progression of the condition, preventing or delaying the onset
of the disease or illness, e.g., prophylactic treatment, enhancing
normal physiological functionality, and the like. Thus, treating
does nor require a cure.
[0088] The term "effective," as that term is used in the
specification and/or claims, means adequate to accomplish a
desired, expected, or intended result. More particularly, a
"therapeutically effective amount" as provided herein refers to an
amount of the presently disclosed particle compositions necessary
to provide the desired therapeutic effect, e.g., an amount that is
effective to prevent, alleviate, ameliorate or otherwise treat
symptoms of disease or prolong the survival of the subject being
treated. As would be appreciated by one of ordinary skill in the
art upon review of the present disclosure and as provided in more
detail herein below, the exact amount required will vary from
subject to subject, depending on age, general condition of the
subject, the severity of the condition being treated, the
particular compound and/or composition administered, and the like.
An appropriate "therapeutically effective amount" in any individual
case can be determined by one of ordinary skill in the art by
reference to the pertinent texts and literature and/or by using
routine experimentation.
[0089] The presently disclosed particle compositions can be
administered therapeutically to achieve a therapeutic benefit or
prophylactically to achieve a prophylactic benefit. By therapeutic
benefit is meant treating the underlying disorder including
eradication or amelioration of one or more of the symptoms
associated with the underlying disorder such that the patient
reports an improvement in feeling or condition, notwithstanding
that the patient can still be afflicted with the underlying
disorder. For example, administration of a particle composition to
a patient suffering from a condition provides therapeutic benefit
not only when the underlying condition is eradicated or
ameliorated, but also when the patient reports a decrease in the
severity or duration of the symptoms associated with the condition.
Therapeutic benefit also includes halting or slowing the
progression of the disease, regardless of whether improvement is
realized by the patient.
[0090] For prophylactic administration, the presently disclosed
particle compositions can be administered to a subject at risk of
developing a particular ocular condition or disorder.
Alternatively, prophylactic administration can be applied to avoid
the onset of symptoms in a patient diagnosed with the underlying
condition or disorder.
[0091] The amount of the presently disclosed particle compositions
administered to a subject will depend upon a variety of factors,
including, for example, the particular indication being treated,
the mode of administration, whether the desired benefit is
prophylactic or therapeutic, the severity of the indication being
treated and the age and weight of the patient, the bioavailability
of the particular active compound, and the like. Determination of
an effective dosage is well within the capabilities of those
skilled in the art.
[0092] Effective dosages can be estimated initially from in vitro
assays. For example, an initial dosage for use in animals can be
formulated to achieve a circulating blood or serum concentration of
active compound that is at or above an IC50 of the particular
therapeutic agent as measured in an in vitro assay known in the
art. Calculating dosages to achieve such circulating blood or serum
concentrations taking into account the bioavailability of the
particular compound is well within the capabilities of skilled
artisans. For guidance, see Fingl & Woodbury, "General
Principles," In: Goodman and Gilman's The Pharmaceutical Basis of
Therapeutics, Chapter 1, pp. 1-46, latest edition, Pagamonon Press,
and the references cited therein.
[0093] Initial dosages also can be estimated from in vivo data,
such as animal models. Animal models useful for testing the
efficacy of therapeutic agents to treat or prevent the various
diseases described above are well-known in the art. Dosage amounts
will depend on, among other factors, the activity of the
therapeutic agent, its bioavailability, the mode of administration
and various factors discussed above. Dosage amount and interval can
be adjusted individually to provide levels of the therapeutic
agents(s) sufficient to maintain a therapeutic or prophylactic
effect. Skilled artisans will be able to optimize effective local
dosages without undue experimentation.
[0094] The presently disclosed particle compositions can be
administered once per day, a few or several times per day, or even
multiple times per day, depending upon, among other things, the
indication being treated and the judgment of the prescribing
physician.
[0095] Preferably, the presently disclosed particle compositions
will provide therapeutic or prophylactic benefit without causing
substantial toxicity. Toxicity of the particle compositions can be
determined using standard pharmaceutical procedures. The dose ratio
between toxic and therapeutic (or prophylactic) effect is the
therapeutic index. Compositions that exhibit high therapeutic
indices are preferred.
[0096] As provided hereinabove, the presently disclosed particles,
in particular embodiments, will contain one or more "active
compounds" or "therapeutic agents." Pharmaceutical compositions
containing the presently disclosed particle compositions also are
provided herein. These pharmaceutical compositions include the
presently disclosed active compounds in a pharmaceutically
acceptable carrier. The term "pharmaceutically acceptable" with
respect to a component, such as a salt, carrier, excipient or
diluent of a composition according to the presently disclosed
subject matter refers to a component that is compatible with the
other ingredients of the composition in that it can be combined
with the presently disclosed particle compositions without
eliminating the therapeutic efficacy of the active compounds or
therapeutic agents and is suitable for use with subjects as
provided herein without undue adverse side effects (including, but
not limited to, toxicity, irritation, and allergic response) to the
subject to which the particular particle composition is
administered. Examples of pharmaceutically acceptable components
include, without limitation, any of the standard pharmaceutical
carriers, such as phosphate buffered saline solutions, water,
emulsions such as oil/water emulsion, microemulsions, and various
types of wetting agents.
[0097] When used to treat or prevent conditions and diseases as
described herein, the presently disclosed active compounds can be
administered singly, as mixtures of one or more active compounds or
in mixture or combination with other agents useful for treating
such diseases and/or the symptoms associated with such
diseases.
[0098] Further, in representative embodiments, certain active
compounds and/or therapeutic agents disclosed herein are prodrugs.
The term "prodrug" refers to a therapeutic agent that has been
chemically derivatized such that, upon administration to a subject,
the derivative is metabolized to yield the biologically-active
therapeutic agent. Accordingly, upon administration to a recipient,
a prodrug is capable of providing (directly or indirectly) a
compound of the presently disclosed subject matter or an
inhibitorily active metabolite or residue thereof. Prodrugs can
increase the bioavailability of the presently disclosed compounds
when such compounds are administered to a subject (e.g., by
allowing an orally administered compound to be more readily
absorbed into the blood) or can enhance delivery of the parent
compound to a biological compartment (e.g., the brain or lymphatic
system) relative to a metabolite species.
[0099] Pharmaceutical compositions containing the presently
disclosed particle compositions, including active compounds (or
prodrugs thereof), can be manufactured by means of conventional
mixing, dissolving, granulating, dragee-making levigating,
emulsifying, encapsulating, entrapping and/or lyophilization
processes. The presently disclosed pharmaceutical compositions can
be formulated in conventional manner using one or more
physiologically acceptable carriers, diluents, excipients or
auxiliaries that facilitate processing of the active compounds into
preparations that can be used pharmaceutically.
[0100] Useful injectable compositions containing the presently
disclosed particle compositions include sterile suspensions,
solutions or emulsions of the active compound(s) in aqueous or oily
vehicles. The compositions also can contain formulating agents,
such as suspending, stabilizing and/or dispersing agents. The
compositions suitable for injection can be presented in unit dosage
form, e.g., in ampules or in multidose containers, and can contain
added preservatives. Alternatively, an injectable composition can
be provided in powder form for reconstitution with a suitable
vehicle, including, but not limited to, sterile water, buffer,
dextrose solution, and the like, before use. To this end, the
presently disclose particles can be dried by any art-known
technique, such as lyophilization, and reconstituted prior to
use.
[0101] In addition to the presently disclosed particle
compositions, the pharmaceutical formulations can contain other
additives, such as pH-adjusting additives. In particular, useful
pH-adjusting agents include acids, such as hydrochloric acid, bases
or buffers, such as sodium lactate, sodium acetate, sodium
phosphate, sodium citrate, sodium borate, or sodium gluconate.
Further, the formulations can contain anti-microbial preservatives.
Useful anti-microbial preservatives include methylparaben,
propylparaben, and benzyl alcohol. The anti-microbial preservative
is typically employed when the formulation is placed in a vial
designed for multi-dose use.
EXAMPLES
[0102] The presently disclosed subject matter now will be described
more fully hereinafter with reference to the accompanying Examples,
in which some, but not all embodiments of the inventions are shown.
The following Examples have been included to provide guidance to
one of ordinary skill in the art for practicing representative
embodiments of the presently disclosed subject matter. In light of
the present disclosure and the general level of skill in the art,
those of skill can appreciate that the following Examples are
intended to be exemplary only and that numerous changes,
modifications, and alterations can be employed without departing
from the scope of the presently disclosed subject matter. The
following Examples are offered by way of illustration and not by
way of limitation.
Example 1
Preparation and Characterization of PEG-Coated Particles
[0103] Fluorescent, carboxyl-modified polystyrene particles
(Molecular Probes, Eugene, Oreg.) were covalently modified with
2-3.4 kDa amine-modified PEG (Nektar Therapeutics, San Carlos,
Calif.) via a carboxyl-amine reaction, as previously published.
Unconjugated PEG was removed by three rounds of washing and
centrifugation. The PEG-coated particles were stored at 4.degree.
C. until use. A near-neutral 4-potential measured by Doppler
anemometry was used to confirm PEG conjugation. These particles are
also referred to herein as coated latex particles.
Example 2
Particle Administration to the Corneal Stroma
[0104] Particles according to Example 1 were administered to the
corneal stroma in one of two ways depending on the most appropriate
dose for a clinical situation. Direct intrastromal injections were
used to provide smaller volumes of particle solution to the cornea.
Such injections involved insertion of a small gauge needle into the
stromal layer of the cornea. These injection sites are most often
self sealing. They can, however, be closed with the aid of corneal
glue and/or contact lens placement if leakage occurs.
[0105] Larger doses of particles were administered by first
creating a pocket in the corneal stroma. The pocket was created
outside the visual axis and the size was determined based on the
required dose. The particles were then administered directly into
the pocket, which was then closed with corneal glue and placement
of a contact lens for the first post-operative day.
Example 3
Particle Administration to the Anterior Chamber
Intraoperative Injection
[0106] Small incisions are created in the cornea during cataract
extraction surgery. These incisions, which are used for removing
the cataractous lens and implanting the artificial lens, are closed
by a process of hydrosealing at the end of surgery. The particles
are injected into the AC through the surgical incision and sealed
in the chamber once the wound is closed.
Non-Operative Administration
[0107] A small gauge needle was inserted through the peripheral
cornea and used to inject the solution of particles according to
Example 1 into the AC. These injection sites are most commonly
self-sealing, however, corneal glue and/or contact lens placement
were used for the first 24 hours to prevent leakage.
Example 4
Particle Administration into the Vitreous Chamber
[0108] Injections of particle solutions into the vitreous chamber
were performed through the pars plana, an anatomic location that is
devoid of vasculature and retinal tissue, limiting the risk of
bleeding and retinal and/or lens injury. A small gauge needle was
used to inject particles according to Example 1. Injection sites of
this size are self sealing, eliminating the need for closure.
Injections were performed after first disinfecting and topically
anesthetizing the site.
Example 5
Sustained and Targeted Drug Delivery with Intrasomal Microparticles
and Nanoparticles for Treating Chronic Keratitis and Corneal Graft
Rejection
Purpose
[0109] Many cases of amoebic and fungal keratitis, as well as
corneal graft rejection, remain refractory to topical therapy.
Intrastromal (IS) injection of medications has been introduced as
an alternative to topical administration, but IS injection remains
limited due to drug loss by diffusion and clearance. The presently
disclosed subject matter demonstrates that IS administration of
micro- and nanoparticles such as latex particles can be used for
sustained delivery of antimicrobials or immunosuppressant agents to
the cornea.
Methods
[0110] This embodiment included studying three groups, each with
three rabbits. The three groups included: (a) a control group
receiving 10 .mu.L of saline into an intrastromal pocket; (b) a
microparticle group receiving 10 .mu.L of 1-.mu.m particles
covalently coated with PEG in the pocket; and (c) a nanoparticle
group receiving 10 .mu.L of 200-nm particles covalently coated with
PEG into the pocket.
[0111] The retention of the particles was assessed by in vivo
fluorescence. The images were obtained at zero (0) minutes; one
hour; six hours; daily for one week; and every other day for
fourteen days. The initial fluorescence value for each eye was used
to determine the relative clearance of particles from the corneal
stroma.
Results
[0112] Micro- and nanoparticles were cleared from the stroma at
similar rates (P<0.05). At one hour, a clearance of 21% of the
1-.mu.m particles and 23% of the 200-nm particles was observed. At
24 hours, a loss of 52% and 41% of the total injection 1-.mu.m
particles and 200-nm particles, respectively, was observed. The
rate of clearance became more gradual with time: at 14 days, 79%
and 73% of the original dose of the 1-.mu.m particles and 200-nm
particles were lost, respectively. The control group had no
detectable fluorescence at any time point.
Conclusion
[0113] The observation that more than 20% of the presently
disclosed particles are still present in the corneal stroma after
14 days indicates that IS micro- and nanoparticles provide a method
for long-term delivery of medications to the cornea and could be
useful in the management and treatment of chronic keratitis and
graft rejection.
Example 6
Intracameral Injection of Particles for Sustained Delivery of
Post-Operative Medications to the Anterior Chamber
Purpose
[0114] Intracameral (IC) administration of antimicrobial and
anti-inflammatory agents during intraocular surgery has been
proposed to decrease the need for post-operative topical drop. Free
drugs, however, are cleared with the aqueous humor (AH). The
presently disclosed subject matter demonstrates the use of
particles for longer-term delivery of medications to the anterior
chamber (AC), by evaluating the clearance rates and complications
associated with the administration of IC particles.
Methods
[0115] Nine rabbit eyes were examined in this embodiment. Baseline
fluorescence and intraocular pressures (IOP) were assessed. Groups
included: (a) control--100 .mu.L of IC saline; (b) uncoated--100
.mu.L of IC 200-nm uncoated latex particles; and (c) coated--100
.mu.L of IC 200-nm latex particle, which were coated with PEG. The
particles were linked to fluorescence tags, which allowed detection
by in vivo fluorescence. Fluorescence images and IOP measurements
were obtained at zero (0) minutes; one hour; six hours; daily for
one week; and every two days for one month. Relative particle
retention was evaluated by comparing fluorescence images to those
obtained a t=0.
Results
[0116] No fluorescence was detected in the control group. Particle
loss was observed immediately after injection in both experimental
groups: Significant percentages of both the coated and uncoated
particles remained after one day and 15 days. After 30 days, 33%
and 18% of the total particles were retained in the coated and
uncoated groups, respectively. A significantly greater clearance of
uncoated particles (P<0.05) was observed. Only one animal, from
the uncoated group, developed elevated IOP after the injection,
which resolved progressively within 16 days.
Conclusion
[0117] The presently disclosed subject matter demonstrates that
intraoperative IC injection of particles of nano-size or larger can
be a useful tool for providing sustained delivery of post-operative
medications to the AC for as long as one month.
Example 7
Intravitreal Particles for the Sustained Treatment of Degenerative
and Proliferative Diseases of the Retina
Purpose
[0118] Intravitreal injection of angiogenesis inhibitors has become
commonplace in the treatment of retinal diseases, such as
age-related macular degeneration and proliferative diabetic
retinopathy. Unfortunately, this route of delivery requires
repeated injections, increasing the risk of infection and retinal
injury. The presently disclosed subject matter determines the
length of time particles can be retained in the vitreous chamber
after pars plana injection and demonstrates the use of the
presently disclosed drug carriers for the long-term treatment of
diseases of a retina.
Methods
[0119] The study was conducted on nine rabbit eyes and included
three groups: (a) a control group received a 100-.mu.L intravitreal
injection of saline; (b) an uncoated group received 100 .mu.L of
intravitreal 200-nm uncoated latex particle solution; and (c) a
coated group received 100 .mu.L of intravitreal 200-nm latex
particles coated with PEG. The baseline fluorescence and
intraocular pressure (IOP) were assessed prior to injection through
the pars plana. The particles were fluorescence tagged and
assessment of retention was made by analysis of in vivo
fluorescence imaging. Images and IOP measurements were obtained at
zero (0) minutes, one hour, daily for one week, and every five days
for one month. The fluorescence images from each time point were
compared to those obtained immediately after the intravitreal
injection to determine the relative retention rates for each
eye.
Results
[0120] No significant differences between the clearance profiles of
the coated and uncoated particles were observed. No significant
decline in the particles retained in the vitreous chambers was
observed over 30 days (P<0.05). No detectable fluorescence
signal was observed in the control group. No changes in IOP were
observed in any group.
Conclusion
[0121] The presently disclosed particles provide sustained and
predictable release of medications and can be an effective system
for long-term intravitreal drug delivery and the treatment of
various retinal diseases.
Example 8
Inflammation Profile Following Intracameral Injection of
Particles
Materials and Methods
Particle Synthesis
[0122] Fluorescent carboxyl-modified polystyrene particles 100-1000
nm in size (Molecular Probes, Eugene, Oreg.) were covalently
conjugated with 2 kDa diamine PEG, according to methods known in
the art.
[0123] PLGA (15 kDa) was fluorescently labeled with Alexa Fluor 647
cadaverine (AF647; Invitrogen Corporation, Carlsbad, Calif.) using
a modified method, as previously described. Fluorescently labeled
nanoparticles were formed by emulsion method. To form the emulsion,
100 mg of PLGA-AF647 dissolved in one ml of dichloromethane (DCM)
was homogenized at 10 k rpm for 2 min in 15 ml of aqueous phase (2%
PVA, 10% F127, or 10% F68), then added to 100 ml aqueous phase
(0.1% PVA, 1% F127, or 1% F68) and stirred for 2 h to remove
solvent. Particles were collected, washed twice, and
resuspended.
[0124] Size and zeta-potential were determined by dynamic light
scattering and laser Doppler anemometry, respectively, using a
Zetasizer Nano ZS90 (Malvern Instruments).
Groups and Numbers
[0125] This study included 30 eyes from 30 New Zealand white
rabbits. There were 5 experimental groups and one control group,
each with n=5 animals. Two experimental groups received
intracameral (IC) injections of polystyrene (PS) particles;
uncoated (PS-COOH) and coated with poly(ethylene) glycol (PS-PEG).
Three groups received IC injections of biodegradable
poly(lactic-co-glycolic acid, PLGA); one group had no pluronics
coating (PLGA-PVA), another with moderate pluronics coating
(PLGA-F68) and another with dense pluronics coating (PLGA-F127).
The control group received a sham IC injection with phosphate
buffered saline (PBS).
Pre-Injection Assessment
[0126] The intraocular pressure (IOP) and anterior chamber (AC)
inflammation were evaluated in all animals to establish baseline
levels before particle suspension injection. Animals with elevated
IOP or any signs of inflammation were excluded from the study. The
animals were anesthetized with an intramuscular injection (IM) of
ketamine/xylazine solution. Once general anesthesia was achieved a
drop of 0.5% proparacaine topical anesthetic solution was instilled
onto the surface of the right eye of the animal and a wire eyelid
speculum was placed to keep the lid open.
[0127] A Reichert Tono-Pen contact tonometer was used to assess the
IOP; five measurements were obtained for each animal at each time
point. A slit-lamp biomicroscope exam was then performed to examine
the AC for signs of inflammation; criteria included presence of
cells, flare and fibrin.
Injection Preparation
[0128] Injections were performed immediately after the particles
were synthesized. The suspension was homogenized using a table-top
lab vortex and doses of 120 .mu.L were measured and pipetted into
individual microcentrifuge tubes. The particle suspensions were
vortexed again immediately prior to drawing them into the
administration syringes. In order to ensure that none of the
particle suspension was lost in the deadspace of the syringe/needle
during injection, an air cushion was created between the plunger
and the particle suspension by first drawing air into the syringe
prior to the suspension.
Particle Injection
[0129] The animals were anesthetized as outlined above. Once
general anesthesia was achieved, a drop of 0.5% proparacaine was
instilled onto the right eye of the animal prior to placement of a
wire eye lid speculum. A 30 gauge needle attached to an empty 1 cc
Luer-lock syringe was inserted into the AC through the peripheral
cornea using a narrow angle of approach, and 120 .mu.L of aqueous
humor (AH) was extracted. While holding the needle in the place in
the AC, the extraction syringe was detached and the syringe
containing the particle suspension (or control PBS) was attached to
the needle and the contents were injected into the AC. The needle
and syringe were quickly withdrawn and a drop of cyanoacrylate
corneal glue was immediately placed on the injection site. The
animals were monitored until anesthesia reversal, at which time
they were returned to their cages.
Post-Injection Assessment
[0130] The animals were evaluated on post-injection days 1, 7, 14
and 30 and the same evaluation procedure was performed on each day.
After general and local anesthesia were achieved, each animal was
examined for gross abnormalities. IOP was measured as indicated
above. Slit-lamp biomicroscopy was performed to evaluate and
quantify AC inflammation. The exams were performed by the same
trained ophthalmologist who was blinded to the assignment of the
treatment and control animals. The AC inflammation was quantified
using a modified version of the Standard Uveitis Nomenclature
clinical grading scheme, as detailed below.
Modified Standardization of Uveitis Nomenclature (SUN) Scheme
Part 1. Grading Scheme for Anterior Chamber Cells
TABLE-US-00002 [0131] Grade Cells in Field 0 <1 0.5 1-5 1 6-15 2
16-25 3 26-50 4 >50
Part 2. Grading Scheme for Anterior Chamber Flare
TABLE-US-00003 [0132] Grade Description 0 None 1 Faint 2 Moderate
(iris and lens details clear) 3 Marked (iris and lens details hazy)
4 Intense (fibrin or plastic aqueous)
Part 3. Grading Scheme for Anterior Chamber Fibrin Reaction
TABLE-US-00004 [0133] Grade Fibrin Morphology 0 None 1 Spots,
non-continuous 2 Lines or semi-transparent membranes 3 Flat opaque
patches 4 Isometric masses
Results
[0134] The mean inflammation scores for each group are presented
below in Table 1 as well as in FIG. 1. At day 1 there was
clinically visible AC inflammation in all animals in all groups,
including the control group. The inflammation trend was similar for
all groups: a rapid rise from the time of injection with a peak
score at Day 1, followed by a progressive decline until the end of
the study (Day 30).
[0135] The inflammation was significantly higher in the PS-COOH,
PLGA-PVA, and PLGA-F68 groups compared to the PS-PEG, PLGA-F127 and
Saline groups at all time points. There was no significant
difference among the scores of PS-COOH, PLGA-PVA and PLGA-F68
groups (at any time point), and likewise there was no significant
difference among the scores of the PS-PEG, PLGA-F127 and Saline
(Control) groups at any time point (P<0.05).
TABLE-US-00005 TABLE 1 The mean AC inflammation scores from among
the animals (n = 5) in each group for each time point evaluated in
this study. Post Injection Day Particle Day 0 Day 1 Day 7 Day 14
Day 30 PS-COOH 0 6.8 4.2 3.8 3.2 PS-PEG 0 5.4 2.8 1.8 1.2 PLGA-PVA
0 8.6 5 4.2 3.6 PLGA-F68 0 7.8 4.4 3.8 3.4 PLGA-F127 0 5.6 2.8 2
1.4 Control 0 5.2 2.2 1.8 1.1
[0136] Although the foregoing subject matter has been described in
some detail by way of illustration and example for purposes of
clarity of understanding, it will be understood by those skilled in
the art that certain changes and modifications can be made without
departing from the spirit and scope of the invention.
[0137] All publications, patent applications, patents, and other
references are herein incorporated by reference to the same extent
as if each publication, patent application, patent, and other
reference was specifically and individually indicated to be
incorporated by reference. It will be understood that, although a
number of patent applications, patents, and other references are
referred to herein, such reference does not constitute an admission
that any of these documents forms part of the common general
knowledge in the art.
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* * * * *