U.S. patent application number 14/608382 was filed with the patent office on 2015-06-11 for photokinetic ocular drug delivery methods and apparatus.
This patent application is currently assigned to BOARD OF REGENTS, THE UNIVERSITY OF TEXAS SYSTEM. The applicant listed for this patent is Bernard F. Godley, Aristides P. Koutrouvelis, Edward R. Kraft, Gabriela A. Kulp. Invention is credited to Bernard F. Godley, Aristides P. Koutrouvelis, Edward R. Kraft, Gabriela A. Kulp.
Application Number | 20150157715 14/608382 |
Document ID | / |
Family ID | 43662202 |
Filed Date | 2015-06-11 |
United States Patent
Application |
20150157715 |
Kind Code |
A1 |
Kraft; Edward R. ; et
al. |
June 11, 2015 |
Photokinetic Ocular Drug Delivery Methods and Apparatus
Abstract
The present invention relates generally to transscleral,
transcorneal, and transocular delivery of biologically active
substances through the tissues, blood vessels and cellular
membranes of the eyes of patients without causing damage to the
cellular surface, tissue or membrane. The invention provides
compositions and methods for enhanced transscleral, transcorneal
and transocular delivery of biologically active substances using
pulsed incoherent light, and particularly the transcleral,
transcorneal or transocular delivery of high molecular weight
biologically active substances to a patient using pulsed incoherent
light. The invention further provides a device for the application
of the pulsed incoherent light to cellular surfaces and membranes
of the eye of a subject using those compositions and methods.
Inventors: |
Kraft; Edward R.;
(Galveston, TX) ; Kulp; Gabriela A.; (Cypress,
TX) ; Godley; Bernard F.; (Galveston, TX) ;
Koutrouvelis; Aristides P.; (Galveston, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kraft; Edward R.
Kulp; Gabriela A.
Godley; Bernard F.
Koutrouvelis; Aristides P. |
Galveston
Cypress
Galveston
Galveston |
TX
TX
TX
TX |
US
US
US
US |
|
|
Assignee: |
BOARD OF REGENTS, THE UNIVERSITY OF
TEXAS SYSTEM
Austin
TX
|
Family ID: |
43662202 |
Appl. No.: |
14/608382 |
Filed: |
January 29, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12903126 |
Oct 12, 2010 |
8948863 |
|
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14608382 |
|
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|
61250371 |
Oct 9, 2009 |
|
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61328625 |
Apr 27, 2010 |
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Current U.S.
Class: |
604/20 |
Current CPC
Class: |
A61K 38/30 20130101;
A61K 31/728 20130101; A61N 5/062 20130101; A61N 2005/0659 20130101;
A61F 9/0017 20130101; A61F 9/0079 20130101; A61K 31/58 20130101;
A61K 41/0057 20130101; A61N 2005/0661 20130101; A61K 31/573
20130101; A61K 45/06 20130101; A61K 38/12 20130101; A61K 47/36
20130101; A61K 38/14 20130101; A61K 9/0048 20130101; A61K 41/00
20130101; A61N 2005/0656 20130101; A61K 31/167 20130101; A61K 38/28
20130101; A61N 2005/0651 20130101; A61K 31/519 20130101; A61K 47/16
20130101; A61K 31/7042 20130101; A61N 2005/0662 20130101 |
International
Class: |
A61K 41/00 20060101
A61K041/00; A61K 31/519 20060101 A61K031/519; A61K 31/573 20060101
A61K031/573; A61K 38/30 20060101 A61K038/30; A61N 5/06 20060101
A61N005/06; A61K 38/28 20060101 A61K038/28 |
Claims
1. A method for the photokinetic transscleral ocular delivery of a
biologically active substance to a subject, the method comprising:
preparing a solution comprising the biologically active substance
and a solvent; applying the solution to an exterior ocular surface
of an eye of the subject; and illuminating the solution on the
exterior ocular surface with a pulsed incoherent light directed
through the solution and towards an interior of the eye of the
subject at a wavelength selected to induce photokinetic transocular
translocation of the biologically active substance.
2. The method of claim 1, wherein the solution further comprises a
gelling agent.
3. The method of claim 1, wherein the biologically active substance
has a molecular weight greater than 500 Daltons.
4. The method of claim 1, wherein the biologically active substance
is selected from one or more anesthetics, anti-infectives,
antibiotics, antifungals, antivirals, antineoplastics, anti-VEGFs,
antineovasculars, steroids, anti-inflammatories, immunomodulators,
gases, antioxidants, nanoparticles, genes, cytokines, peptides,
antithrombotics, nucleotides, RNAs, anti-compliment medications,
compliment modulating medications, peptides, immunoglobulins,
antibodies, antigens, anti-glaucoma medications, hormones,
vitamins, amino acids, silicone liquids, heavy liquid tamponades,
cellular nutrients, anti-apoptotic agents, anticoagulants, tissue
adhesives, cofactors, coenzymes, enzymes and combinations
thereof.
5. The method of claim 4, wherein the hormone is selected from the
group consisting of methionine enkephalin acetate, leucine
enkephalin, angiotensin II acetate, .beta.-estradiol, methyl
testosterone, methyl prednisolone, corticosteroids, budenoside,
progesterone, insulin, and combinations thereof.
6. The method of claim 4, wherein the biologically active substance
is insulin.
7. The method of claim 4, wherein the biologically active substance
is triamcinolone acetonide.
8. The method of claim 4, wherein the antibody is a monoclonal
antibody selected from the group consisting of adalimumab,
bevacizumab, daclizumab, etanercept, infliximab, ranibizumab,
rituximab, and combinations thereof.
9. The method of claim 4, wherein the antibiotic is selected from
the group consisting of amoxycillin, ampicillin, penicillin,
clavulanic acid, aztreonam, imipenem, streptomycin, gentamicin,
vancomycin, clindamycin, ephalothin, erythromycin, polymyxin,
bacitracin, amphotericin, nystatin, rifampicin, tetracycline,
coxycycline, chloramphenicol, zithromycin, and combinations
thereof, as well as pharmaceutically acceptable derivatives
thereof.
10. The method of claim 1, wherein the biologically active
substance is insulin-like growth factor-1 (IGF-1).
11. The method of claim 4, wherein the antiviral agent is selected
from the group consisting of guanosine derivatives, nucleoside
phosphonates, phosphonic acid derivatives, oligonucleotides, and
combinations thereof, as well as pharmaceutically acceptable salts,
solvates, hydrates, and derivatives thereof.
12. The method of claim 4, wherein antiviral drug is selected from
the group consisting of foscarnet, fomivirsen sodium, trifluridine,
vidarabine, and combinations thereof, as well as pharmaceutically
acceptable derivatives thereof.
13. The method of claim 1, wherein the biologically active
substance is methotrexate.
14. The method of claim 2, wherein the gelling agent selected from
the group consisting of hydroxyethyl cellulose, pectines, agar,
alginic acid and its salts, guar gum, pectin, polyvinyl alcohol,
polyethylene oxide, cellulose, propylene carbonate, polyethylene
glycol, hexylene glycol sodium carboxymethylcellulose,
polyacrylates, polyoxyethylene-polyoxypropylene block copolymers,
pluronics, wood wax alcohols, tyloxapol, and combinations thereof,
as well as pharmaceutically acceptable derivatives thereof.
15. The method according to claim 1, wherein the solvent is an
aqueous solvent or an organic solvent.
16. The method according to claim 15, wherein the aqueous solvent
is an aqueous solution of ethyl lactate or propylene glycol.
17. The method according to claim 1, wherein the pulsed incoherent
light is selected from the group consisting of fluorescent,
ultraviolet, visible, near infrared, LED (light emitting diode),
and halogen light.
18. The method according to claim 1, wherein the wavelength is in a
range from about 260 nm to about 760 nm.
19. The method according to claim 1, wherein the wavelength is in a
range from about 340 nm to about 900 mm.
20. The method according to claim 1, wherein the wavelength is
selected from the group consisting of 350 nm, 370 nm, 390 nm, 405
nm, 450 nm and combinations thereof.
21. The method according to claim 1, wherein the pulsed incoherent
light is applied at a pulse rate between about 1.7 cycles per
second (cps) and about 120 cps.
22. The method according to claim 21, wherein the pulse rate is
between about 1.7 cps and about 80 cps.
23. The method according to claim 1, wherein the pulsed incoherent
light is applied at a duty cycle is between about 50% and about
75%.
24. A method for the transcleral delivery of one or more high
molecular weight biologically active substances to the eye of a
subject, the method comprising: preparing a solution comprising a
biologically active substance having a molecular weight greater
than 1000 Daltons and a solvent; applying the solution to an
exterior ocular surface of a subject; illuminating the solution on
the exterior ocular surface with a pulsed incoherent light directed
through the solution and towards an interior of the eye of the
subject at a wavelength selected to induce photokinetic transocular
translocation of the biologically active substance.
25. The method of claim 24, wherein the biologically active
substance has a molecular weight of greater than 50,000
Daltons.
26. The method of claim 24, wherein the biologically active
substance is insulin, bevacizumab, human growth factor, and
combinations and/or pharmaceutically acceptable salts, solvates, or
derivatives thereof.
27. The method of claim 24, wherein the biologically active
substance is selected from the group consisting of anti-infectives,
antibiotics, antifungals, antivirals, antineoplastics, anti-VEGFs,
antineovasculars, steroids, anti-inflammatories (including NSAIDS),
immunomodulators, antioxidants, nanoparticles, genes, cytokines,
peptides, antithrombotics, polynucleotides, RNAs, anti-compliment
medications, compliment modulating medications, immunoglobulins,
antibodies, antigens, anti-glaucoma medications, hormones,
vitamins, silicone liquids, heavy liquid tamponades, cellular
nutrients, anti-apoptotic agents, anticoagulants, tissue adhesives,
cofactors, coenzymes, enzymes and combinations thereof.
28. A method for the treatment of a subject having a VEGF-related
angiogenic disease affecting the eyes of the subject, the method
comprising administering to a subject in need thereof a
therapeutically effective amount of a biologically active substance
using the method of claim 1, wherein the VEGF-related angiogenic
disease is selected from the group consisting of cancer,
age-related macular degeneration (AMD), diabetic retinopathy, and
combinations thereof.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of and claims priority to
U.S. application Ser. No. 12/903,126, filed Oct. 12, 2010,
published as 2012/0125076 on May 26, 2011 and issuing on Feb. 3,
2015 as U.S. Pat. No. 8,948,863, which in turn claims priority to
U.S. Provisional Patent Application Ser. No. 61/250,371, filed Oct.
9, 2009, and U.S. Provisional Patent Application Ser. No.
61/328,625, filed Apr. 27, 2010, all of which are incorporated
herein by reference in their entireties.
FIELD OF THE INVENTION
[0002] The inventions disclosed and taught herein relate generally
to photokinetic delivery of biologically active substances across a
mammalian ocular surface. More particularly, the invention provides
methods, apparatus, and compositions for the
transcleral/transcorneal, ocular delivery of biologically active
substances, such as therapeutic agents, using pulsed incoherent
light.
BACKGROUND OF THE INVENTION
[0003] Millions of people worldwide suffer from ocular diseases,
many of which lead to visual impairment. Anterior segment diseases
(dry eye, eye lid diseases) can be successfully treated with
topical administration of drugs in eye-drop formulation. However,
this minimally invasive technique only allows for less than about
5%, and many times less than 1%, of the administered drug to reach
the drug target site before being washed away by tear formation or
being absorbed systemically by the surrounding eye tissues. Eye
drops may not be an effective method for administering larger
molecular weight drugs into the eye for treatment of posterior
segment eye diseases such as age-related macular degeneration,
diabetic retinopathy, retinitis pigmentosa, and primary ocular
lymphoma.
[0004] Systemic administration of an eye targeted drug has very
poor bioavailability within the eye due to blood-ocular barriers
that normally protect the eye from circulating antigens,
inflammatory mediators, and pathogens. Typically, systemic
administration does not yield therapeutic drug levels in the
posterior vitreous, retina, or choroid, and although systemic
administration can deliver drugs to the posterior eye, the large
systemic doses necessary to achieve intraocular therapeutic levels
are often associated with significant side effects.
[0005] As a result of these issues, direct intravitreal drug
administration by needle injection is the current standard of care
for many diseases of the eye. Recent drug formulation technologies
have provided increased bioavailability and sustained release of
drugs that are delivered by intravitreal needle injection. Even
with drug formulation advancements, repeated invasive injections
are required over extended periods of months and years.
Intravitreal administration of drugs by needle injection is
associated with an entirely new set of potentially catastrophic
side effects such as infection, intravitreal hemorrhage or retinal
detachment. Estimates in the literature range from 0.02% (Peyman,
et al, Retina, Vol. 29(7), pp. 875-912 (2009)) to 0.2% (Jager, R.
D., et al., Invest. Ophthalmol. Vis. Sci., 45 (2004)) which would
result in between 200 to 2,000 iatrogenic potentially blinding eye
infections this year alone. Retinal detachment is estimated at 0.9%
prevalence (Jager, 2004) from intravitreal injection, which
translates to approximately 9,000 retinal detachments this year
from this procedure. Additionally, ocular injections are painful
and costly. Many disease states may require frequent drug
administration directly into the eye to reach and maintain
therapeutic levels. An effective, minimally invasive method of
intraocular drug delivery is wanting. The proposed ocular drug
delivery system overcomes the problems with repeated ocular needle
injections and may be simple enough for home use.
[0006] It is widely recognized that stimulation of the optical
sites of organic molecules result in conformational changes of the
molecule which may produce a physical change in the shape of the
molecule. When this stimulation is stopped the molecule would then
return to a resting state and original physical shape. Also, if the
stimulation is a low power, the relaxational time would be longer
than if the molecule was stimulated with high optical power. The
combination of low power and slow cyclical stimulation of the
molecular optical sites would result in reversible conformational
changes causing the molecule to bend and flex resulting in gross
physical movement.
[0007] Passive transmembrane permeation is generally time and
molecular weight (MW) dependent wherein larger molecules have less
permeation flux rates than smaller molecules. While not intending
to be bound by any theories, it is hypothesized that if a drug
molecule in a pharmacologically acceptable formulation is placed on
the surface of the sclera/cornea and cyclically illuminated with a
selected wavelength of light at a selected pulse rate, the
resulting cyclic physical shape change of the molecule may cause
gross movement and result in the migration of the molecule across
the sclera membrane. It is further hypothesized that narrow
wavelength incoherent (non-laser) light from a light emitting diode
(LED) source could be used for optical stimulation and that
non-ionizing visible light with these characteristics would not be
harmful to the drug molecule or the sclera itself. Applicants
further hypothesize that the permeation with this system may be
less molecular weight dependent than with passive transmembrane
permeation methodologies.
[0008] The penetration of biologically active substances through
the intraocular tissues occurs by either passive or active
transport mechanisms, typically through the corneal and/or the
non-corneal (conjunctival-scleral) pathways. Passive delivery or
diffusion relies on a concentration density gradient between the
drug at the outer surface and the inner surface of the biological
barrier to be penetrated. The diffusion rate is proportional to the
gradient and is modulated by a molecule's size, hydrophobicity,
hydrophilicity and other physiochemical properties as well as the
area of the absorptive surface. Typically, topically applied drugs
reach the intraocular tissues by either the corneal and/or the
non-corneal (conjunctiva-scleral) pathways, and efforts have been
focused on either enhancing transcellular drug penetration by
increasing drug lipophilicity through the use of prodrugs or
analogs, or improving paracellular penetration by using enhancers
to open tight junctions (Lee, et al., J. Ocul. Pharmacol, Vol. 2,
pp. 67-108 (1986)). However, it is common to see about 1% or less
of an applied dose absorbed across the cornea and conjunctiva to
reach the anterior segment of the eye (Lee, et al., in RETINA, 3rd
Ed., Mosby, St. Louis, pp. 2270-2285 (2001)). Examples of passive
delivery systems include ocularly-applied transdermal patches for
controlled delivery of, for example, enkephalins, leupeptin (serine
protease inhibitor), camostat mesylate (aminopeptidase inhibitor),
nitroglycerine (angina), scopolamine (motion sickness), fentanyl
(pain control), nicotine (smoking cessation), estrogen (hormone
replacement therapy), testosterone (male hypogonadism), clonidine
(hypertension), and lidocaine (topical anesthesia). The controlled
delivery of these drugs can include the use of polymer matrices,
reservoirs containing drugs with rate-controlling membranes and
drug-in-adhesive systems.
[0009] In contrast, active delivery relies on ionization of the
drug or other pharmacologically active substances and on means for
propelling the charged ions through the tissue. The rate of active
transport varies with the method used to increase movement and
propulsion of ions, but typically this transport provides a faster
delivery of biologically active substances than that of passive
diffusion. Active transport delivery systems include methods such
as subconjunctival ocular drug delivery, iontophoresis (transcleral
and transcleral/conjunctival), and a variety of other routes which
involve carrier-mediated drug transport systems.
[0010] Subconjunctival ocular drug delivery is an active transport
method of attempting to elevate intraocular drug concentrations and
minimize the frequency of dosing. Compared with direct intravitreal
injection, this approach is less risky to the patient, and less
invasive. Since the sclera is much more permeable than conjunctiva,
the formidable permeability barrier consisting of both the cornea
and the conjunctiva can be avoided all together with this approach.
Advantages of subconjunctival ocular drug delivery, such as by the
use of subconjunctival implants with nano/microparticles and matrix
materials, compared to subconjuctival injection of solution, is the
achievement of higher drug concentrations and sustained release of
the drug into both the vitreous humor and retinal areas (Gilbert,
J. A., et al., J. Control. Release, Vol. 89, pp. 409-417
(2003)).
[0011] Iontophoresis is a technique used to guide one or more
therapeutic ions in solution into the tissues and blood vessels of
the body by means of a galvanic or direct electrical current
supplied to wires that are connected to skin-interfacing
electrodes. Although ionotophoresis provides a method for
controlled drug delivery transdermally, irreversible skin damage
can occur from galvanic and pH burns resulting from electrochemical
reactions that occur at the electrode and skin interface.
Consequently, its application to ocular therapies has been limited,
with limited reports of its use in delivering molecules into the
eyes of patients. For example, Asahara reported the use of
transscleral iontophoresis to deliver 6-carboxyfluorescein-labeled
phosphorothioate oligonucleotides and a 4.7 kb plasmid that
expressed the green fluorescent protein (GFP) into albino rabbit
eyes, with the nucleotides being detected in the anterior chamber,
vitreous, and posterior retina with no alteration in length of the
oligonucleotides (Asahara, et al., Japn. J. Ophthalmol. Vol. 45,
pp. 31-39 (2001)). More recently, a low-current, non-invasive
iontophoretic treatment using dexamethasone-loaded hydrogels showed
potential value in increasing the drug penetration to the anterior
and posterior segments of the eye. See, Eljarrat-Binstock, E., et
al., J. Controlled Release, Vol. 106(3) 386-390 (2005); and Myles,
M. E., et al., Advanced Drug Delivery Reviews, Vol. 57, pp.
2063-2079 (2005)).
[0012] Other approaches to ocular drug delivery problems have
included the use of ocular/ophthalmic inserts (e.g., OCUFIT
SR.RTM.), collagen shields, vesicular systems, the use of liposomes
and niosomes, the development of bioadhesives, mucoadhesive dosage
forms, the use of lyophilisate carrier systems, and the use of
nanoparticles and microparticles such as nanospheres made up of
poly-d,l-lactic acid (PLA), polymethylmethacrylate (PMMA),
cellulose, poly-ethyl-caprolactone (PECL), or even chitosan (CS)
nanoparticles (DeCampos, et al., Pharm. Res., Vol. 21(5) 803
(2004)) as part of polymeric drug delivery systems for drug
absorption in the eye. These approaches to drug delivery to the eye
have been reviewed extensively in the medical literature. See, Das,
S. & Suresh, P. K., Int'l. J. Drug Delivery, 2, pp. 12-21
(2010); and, Sultana, Y., et al., Current Drug Delivery, Vol. 3,
pp. 207-217 (2006)). However, many of these approaches suffer
limitations as well, such as being suitable only for delivering
therapeutic molecules of a limited size (e.g., molecular weights of
less than 200 Da), or unappealing side affects or potential for
added eye damage for the patient seeking treatment.
[0013] Because of the inherent problems of the above-identified
methods, a need exists for a safe and efficient transocular drug
delivery method that eliminates side-effects and damage to the
barrier function or appearance of the patient's eye caused by drug
administration, and allows for a wide range of biologically active
substances to be administered by such a method in therapeutically
effective amounts. It would therefore be desirable to provide
compositions, methods, and apparatuses to address these
problems.
[0014] In vitro methods described within the present disclosure
were developed to demonstrate the facilitated translocation of two
separate compounds through sclera and corneal tissue using pulsed
light. These in vitro studies, as described herein, suggest that
the hypotheses proposed by the applicants been confirmed. The
method of ocular drug delivery by pulsed incoherent light as
described herein is referred to as "Photokinetic Ocular Drug
Delivery" (PODD).
BRIEF SUMMARY OF THE INVENTION
[0015] The novel technology described herein generally relates to
devices and methods for transscleral/transcorneal needleless drug
administration. Specifically, the technology is an ocular drug
delivery method wherein a drug applied to scleral/corneal tissue is
illuminated with a selected narrow wavelength light from a LED
source and pulsed at a selected frequency that then causes the drug
to permeate into and through the tissue. The technology comprises
in vitro methods for the selection of optical properties of light
emitting devices applied to specific drug formulations thus
defining in vivo administration systems. The technology provides a
non-invasive method using light and drug reservoir devices to
introduce drugs into the eye without the use of needles. The system
is safer and less costly than ocular drug administration by needle
injection.
[0016] In accordance with one aspect of the present disclosure, a
method for the photokinetic transscleral ocular delivery of a
biologically active substance to a subject is described, the method
comprising preparing a solution comprising the biologically active
substance and a solvent; applying the solution to a cellular
surface of an eye of the subject; illuminating the solution on the
cellular surface with a pulsed incoherent light having a selected
wavelength, pulse rate and pulse duration or duty cycle; and
allowing the solution to permeate through the cellular surface.
[0017] In accordance with a further aspect of the present
disclosure, a device for photokinetic transscleral ocular drug
delivery is described, the device comprising a generator that
provides an oscillating electrical pulse; at least one light
emitting diode that receives the oscillating electrical pulse and
responds by providing an incoherent light; and, a drug reservoir
cell that holds a solution comprising a high molecular weight
biologically active substance and a solvent; wherein the drug
reservoir cell is positioned to receive the incoherent light. In
further accordance with this aspect of the disclosure, the
generator is an electrical or repeat cycle square wave pulse
generator. In further accordance with this aspect of the
disclosure, the device includes a light pad having at least one
light emitting diode (LED) embedded within it.
[0018] In accordance with another aspect of the present disclosure,
an in-vitro method of photokinetic transscleral drug delivery to
the eye of a subject is described, the method comprising preparing
a solution comprising a biologically active substance and a
solvent; applying the solution to an ocular cellular surface of a
subject; illuminating the solution on the ocular cellular surface
with a pulsed incoherent light having a selected wavelength, pulse
rate and pulse duration with a device; and allowing the solution to
permeate through the ocular cellular surface.
[0019] In further accordance with aspects of the present
disclosure, methods for the transcleral delivery of one or more
high molecular weight biologically active substances to the eye of
a subject in need of such treatment is described, the method
comprising preparing a solution comprising a high molecular weight
biologically active substance and a solvent applying the solution
to an ocular cellular surface of a subject; illuminating the
solution on the ocular cellular surface with a pulsed incoherent
light having a selected wavelength, pulse rate and pulse duration
with a device; and allowing the solution to permeate through the
ocular cellular surface. In further accordance with this aspect of
the disclosure, the high molecular weight biologically active
substance ranges in size from about 100 Da to greater than about
4500 kDa. In further aspects of the disclosure, the high molecular
weight biologically active substance has a molecular weight of more
than 1,000 Daltons, and in still further aspects, the high
molecular weight biologically active substance has a molecular
weight of more than 50,000 Daltons.
[0020] In accordance with yet another aspect of the present
disclosure, a method for the treatment of a subject having a
VEGF-related angiogenic disease affecting the eyes of the subject
is described, the method comprising administering to a subject in
need thereof a therapeutically effective amount of a biologically
active substance using the transscleral/transcorneal PODD drug
delivery methods described herein, wherein the VEGF-related
angiogenic disease is selected from the group consisting of cancer,
age-related macular degeneration (AMD), and diabetic
retinopathy.
[0021] In accordance with a further aspect of the present
disclosure, a process for treating an infection or disorder in a
tissue of an eye of a subject is described, the process of which
comprises transclerally or transcorneally delivering a therapeutic
composition to an eye using the photokinetic ocular drug delivery
methods described herein, wherein the therapeutic composition
comprises a biologically active substance having a molecular weight
of at least 500 Daltons, a solvent, and optionally a gelling
agent.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0022] The following figures form part of the present specification
and are included to further demonstrate certain aspects of the
present invention. The invention may be better understood by
reference to one or more of these figures in combination with the
detailed description of specific embodiments presented herein.
[0023] FIG. 1 illustrates an exemplary photokinetic transscleral
drug delivery system in accordance with the present disclosure.
[0024] FIG. 2 illustrates a close-up view of the system of FIG. 1,
showing the photokinetic patch applied to the sclera under the eye
lid.
[0025] FIG. 3 illustrates a top view of the photokinetic eye patch
of FIG. 1.
[0026] FIG. 4 illustrates a cross-sectional view through the patch
of FIG. 1, taken along line A-A.
[0027] FIG. 5 illustrates an exemplary photokinetic eye patch with
at least one LED embedded in the patch material.
[0028] FIG. 6 illustrates exemplary Franz diffusion cell apparatus
for in vitro determination of photokinetic conditions of light
wavelength and pulse rate.
[0029] FIG. 7 illustrates a spectrophotometry light absorbance scan
of methotrexate (MTX).
[0030] FIG. 8 illustrates MTX permeation PODD at 350 nm@24 CPS vs.
passive permeation controls per cm.sup.2 of sclera at 3 time
points.
[0031] FIG. 9 illustrates MTX permeation PODD at 370 nm@24 CPS vs.
passive permeation controls.
[0032] FIG. 10 illustrates PODD Insulin permeation at 405 and 450
nm vs. control for 24 hours at 24 CPS. Herein a 200 IU/mL mixture
in a drug carrier solution was placed in the Franz donor cell. A
large difference in permeation is noted here also even within a
narrow range of light wavelength.
[0033] FIG. 11 illustrates MTX permeation PODD at 370 nm@24 CPS vs.
passive permeation controls per cm.sup.2 of sclera over a short (60
minute) exposure range.
[0034] FIG. 12 illustrates the effect of a variety of wavelengths
on permeating vancomycin through scleral tissue using PODD
cells.
[0035] FIG. 13 illustrates the effect of 405 and 450 nm
wavelength@24 CPS verses passive permeation controls on permeating
insulin through scleral tissue using PODD cells.
[0036] FIG. 14 illustrates the effect of 405 and 450 nm
wavelength@24 CPS versus passive permeation controls on permeating
insulin like growth factor 1 through scleral tissue using PODD
cells.
[0037] FIG. 15 illustrates the effect of 405 and 450 nm
wavelength@24 CPS versus passive permeation controls on permeating
Avastin.TM. through scleral tissue using PODD cells.
[0038] FIG. 16 illustrates the effect of 405 and 450 nm
wavelength@24 CPS versus passive permeation controls on permeating
hyaluronic acid (HA) through scleral tissue using PODD cells.
[0039] FIG. 17 illustrates a summary comparison of the size of
biologically active materials which can be
transsclerally/transcorneally applied using the procedures and
apparatus of the present disclosure.
[0040] FIG. 18A-18C illustrate rabbit optic disc imaging results of
fluorescent tagged human insulin administered with the PODD system
of the present disclosure.
[0041] FIGS. 19 A-F illustrate three concentrations of human FITC
labeled insulin used in the PODD device vs. passive permeation of 4
mU/mL in the various fluids and tissues of the rabbit eye (60
minute exposure).
[0042] While the inventions disclosed herein are susceptible to
various modifications and alternative forms, only a few specific
embodiments have been shown by way of example in the drawings and
are described in detail below. The figures and detailed
descriptions of these specific embodiments are not intended to
limit the breadth or scope of the inventive concepts or the
appended claims in any manner. Rather, the figures and detailed
written descriptions are provided to illustrate the inventive
concepts to a person of ordinary skill in the art and to enable
such person to make and use the inventive concepts.
DEFINITIONS
[0043] The following definitions are provided in order to aid those
skilled in the art in understanding the detailed description of the
present invention. Units, prefixes, and symbols may be denoted in
their SI accepted form. Unless otherwise indicated, nucleic acids
are written left to right in 5' to 3' orientation, and amino acid
sequences are written left to right in amino to carboxy
orientation, respectively. Numeric ranges are inclusive of the
numbers defining the range and include each integer within the
defined range. Amino acids may be referred to herein by either
their commonly known three letter symbols (e.g., Pro for proline),
or by the one-letter symbols recommended by the IUPAC-IUB
Biochemical Nomenclature Commission. Nucleotides, likewise, may be
referred to by their commonly accepted single-letter codes. The
terms defined below are more fully defined by reference to the
specification as a whole.
[0044] The term "subject", as used herein, refers to any animal
(i.e., vertebrates and invertebrates) including, but not limited to
humans and other primates, rodents (e.g., mice, rats, and guinea
pigs), lagamorphs (e.g., rabbits), bovines (e.g, cattle), ovines
(e.g., sheep), caprines (e.g., goats), porcines (e.g., swine),
equines (e.g., horses), canines (e.g., dogs), felines (e.g., cats),
domestic fowl (e.g., chickens, turkeys, ducks, geese, other
gallinaceous birds, etc.), as well as feral or wild animals,
including, but not limited to, such animals as ungulates (e.g.,
deer), bear, fish, lagamorphs, rodents, birds, etc. It is not
intended that the term be limited to a particular age or sex. Thus,
adult and newborn subjects, as well as fetuses, whether male or
female, are encompassed by the term.
[0045] The term "biologically active substance" refers generally to
any chemical, drug, antibiotic, peptide, hormone, protein, DNA, RNA
and mixtures thereof that affects biological pathways or interacts
with cellular components.
[0046] The term "chemical" denotes any naturally found or
synthetically made small molecule or polymer. A chemical can be a
polar (hydrophilic), non-polar (hydrophobic), oleophobic or
oleophilic compound. Accordingly, the invention described herein is
particularly useful for transport of compounds with of high
molecular weight, which can be polar, non-polar, oleophobic,
including fluorochemicals, and oleophilic, across at least the
sclera of a patient.
[0047] The term "drug" denotes any natural or synthetic compound
used for therapeutic treatment in mammals. Examples of drugs
include, but are not limited to, anti-infective, antibiotic,
antifungal, antineoplastics, anti-VEGF, antineovasculars, steroids,
anti-inflammatory, immunomodulators, gas, antioxidants,
nanoparticles, genes, cytokines, peptides, antithrombotics,
nucleotides, RNAs, anti-compliment medications, compliment
modulating medications, peptides, immunoglobulins, antibodies,
antigens, anti-glaucoma medications, hormones, vitamins, silicone
liquids, heavy liquid tamponades, cellular nutrients,
anti-apoptotic agents, anticoagulants, tissue adhesives, cofactors,
coenzymes, and enzymes. Specific FDA approved drugs which may be
delivered by the PODD system described herein include, but are not
limited to, triamcinolone acetonide (Kenalog; Bristol Myers Squibb,
New York, N.Y.), pegaptanib (Macugen; OSI/Eyetech and Pfizer, New
York, N.Y.), bevacizumab (Avastin; Genentech, San Francisco); and
ranibizumab (Lucentis; Genentech). Numerous other agents available
on an investigational basis such as VEGF trap (Regeneron;
Tarrytown, N.Y.) may also be included.
[0048] Vitamins are organic chemicals that are essential for
nutrition in mammals and are typically classified as fat-soluble or
water-soluble. Vitamins required to maintain health in humans
include, but are not limited to, vitamin A (retinol), precursor to
vitamin A (carotene), vitamin B.sub.1 (thiamin), vitamin B.sub.2
(riboflavin), vitamin B.sub.3 (nicotinic acid), vitamin B
(pantothenic acid), vitamin C (ascorbic acid), vitamin D
(calciferol), vitamin E (tocopherol), vitamin H (biotin) and
vitamin K (napthoquinone derivatives).
[0049] The term "antibiotic" refers to any natural or synthetic
substance that inhibits the growth of or destroys microorganisms in
the treatment of infectious diseases. Although not an exhaustive
list, examples of antibiotics include amoxycillin, ampicillin,
penicillin, clavulanic acid, aztreonam, imipenem, streptomycin,
gentamicin, vancomycin, clindamycin, cephalothin, erythromycin,
polymyxin, bacitracin, amphotericin, nystatin, rifampicin,
tetracycline, doxycycline, chloramphenicol and zithromycin.
[0050] The term "peptide" refers to a compound that contains 2 to
50 amino acids and/or imino acids connected to one another. The
amino acids can be selected from the 20 naturally occurring amino
acids. The twenty conventional amino acids and their abbreviations
follow conventional usage. See, for example, Immunology--A
Synthesis (2.sup.nd Edition, E. S. Golub and D. R. Gren, Eds.,
Sinauer Associates, Sunderland, Mass. (1991)), which is
incorporated herein by reference. The amino acids can also be
selected from non-natural amino acids such as those available from
Sigma-Aldrich (St. Louis, Mo.), including but not limited to
alicyclic amino acids, aromatic amino acids, .beta.-amino acids,
.gamma.-amino acids, norleucine, ornithine, N-methyl amino acids,
homo-amino acids, and derivatives of natural amino acids, such as
4-nitro-phenylalanine and xanthenyl-L-asparagine. Although not an
exhaustive list, examples of suitable peptides include
glycine-tyrosine, valine-tyrosine-valine,
tyrosine-glycine-glycine-phenylalanine-methionine,
tyrosine-glycine-glycine-phenylalanine-leucine and aspartic
acid-arginine-valine-tyrosine-isoleucine-histidine-proline-phenylalanine.
[0051] The term "hormone" refers to a substance that originates in
an organ, gland, or part, which is conveyed through the blood to
another part of the body, stimulating it by chemical action to
increased functional activity or to increase secretion of another
hormone. Although not an exhaustive list, examples of hormones
include methionine enkephalin acetate, leucine enkephalin,
angiotensin II acetate, .beta.-estradiol, methyl testosterone,
progesterone and insulin.
[0052] A polypeptide, as used herein, is defined as a chain of
greater than 50 amino acids and/or imino acids connected to one
another.
[0053] The term "protein", as used herein, refers to a large
macromolecule composed of one or more polypeptide chains. The term
"isolated protein" is a protein that by virtue of its origin or
source of derivation (1) is not associated with naturally
associated components that accompany it in its native state, (2) is
free of other proteins from the same species (3) is expressed by a
cell from a different species, or (4) does not occur in nature.
Thus, a protein that is chemically synthesized or synthesized in a
cellular system different from the cell from which it naturally
originates will be "isolated" from its naturally associated
components. A protein may also be rendered substantially free of
naturally associated components by isolation, using protein
purification techniques well known in the art.
[0054] The terms DNA and RNA as referred to herein mean
deoxyribonucleic acid and ribonucleic acid, respectively. The term
"polynucleotide" means a polymeric form of nucleotides of at least
10 bases in length, either ribonucleotides or deoxynucleotides or a
modified form of either type of nucleotide. The term includes
single and double stranded forms.
[0055] "Gelling agents," according to the present disclosure, are
compounds that can behave as reversible or non-reversible networks.
Under certain conditions, a gelling agent can be placed in a
solvent to form a viscous solution. Under other conditions, that
same gelling agent can be placed in the same or different solvent
to form a gel. The role of gelling agents according to the
invention is to prevent evaporation loss of the biologically active
substance in the appropriate solvent. Examples of gelling agents
include, but are not limited to, hydroxyethyl cellulose,
NATRASOL.TM., pectines, agar, alginic acid and its salts, guar gum,
pectin, polyvinyl alcohol, polyethylene oxide, cellulose and its
derivatives, propylene carbonate, polyethylene glycol, hexylene
glycol sodium carboxymethylcellulose, polyacrylates,
polyoxyethylene-polyoxypropylene block copolymers, pluronics, wood
wax alcohols and tyloxapol.
[0056] The term "solvent" according to the present disclosure is
any aqueous or organic solvent that can be combined with the
biologically active agent to form a solution. In one embodiment,
the aqueous solvent is water. In another embodiment, the solvent
can be an aqueous solution of either ethyl lactate or propylene
glycol, both of which act as permeation enhancers. Alternately, the
term "solvent" can also mean an adhesive used to embed a
biologically active substance, for example, in a patch. Solvent can
also refer to a pharmaceutically-acceptable medium combined with
the biologically active substance to be used in powder form.
[0057] The term "therapeutically effective amount", as used herein,
refers to an amount of an antibody, polypeptide, or other drug
effective to "treat" a disease or disorder in a subject or mammal.
In the case of cancer, the therapeutically effective amount of the
drug may reduce the number of cancer cells; reduce the tumor size;
inhibit (i.e., slow to some extent and preferably stop) cancer cell
infiltration into peripheral organs; inhibit (i.e., slow to some
extent and preferably stop) tumor metastasis; inhibit, to some
extent, tumor growth; and/or relieve to some extent one or more of
the symptoms associated with the cancer. To the extent the drug may
prevent growth and/or kill existing cancer cells, it may be
cytostatic and/or cytotoxic.
[0058] The phrase "pharmaceutically acceptable salt" as used herein
is meant to refer to those salts which are, within the scope of
sound medical judgment, suitable for use in contact with the
tissues of humans and lower animals without undue toxicity,
irritation, allergic response and the like and are commensurate
with a reasonable benefit/risk ratio. Pharmaceutically acceptable
salts are well-known in the art. For example, P. H. Stahl, et al.
describe pharmaceutically acceptable salts in detail in "Handbook
of Pharmaceutical Salts: Properties, Selection, and Use" (Wiley
VCH, Zunch, Switzerland: 2002). The salts can be prepared in situ
during the final isolation and purification of the compounds of the
present invention or separately by reacting a free base function
with a suitable organic acid. Representative acid addition salts
include, but are not limited to acetate, adipate, alginate,
citrate, aspartate, benzoate, benzenesulfonate, bisulfate,
butyrate, camphorate, camphorsufonate, digluconate,
glycerophosphate, hemisulfate, heptanoate, hexanoate, flimarate,
hydrochloride, hydrobromide, hydroiodide,
2-hydroxyethansulfonate(isethionate), lactate, maleate,
methanesulfonate, nicotinate, 2-naphthalenesulfonate, oxalate,
pamoate, pectinate, persulfate, 3-phenylpropionate, picrate,
pivalate, propionate, succinate, tartrate, thiocyanate, phosphate,
glutamate, bicarbonate, p-toluenesulfonate and undecanoate. Also,
the basic nitrogen-containing groups can be quaternized with such
agents as lower alkyl halides such as methyl, ethyl, propyl, and
butyl chlorides, bromides and iodides; dialkyl sulfates like
dimethyl, diethyl, dibutyl and diamyl sulfates; long chain halides
such as decyl, lauryl, myristyl and stearyl chlorides, bromides and
iodides; aryl alkyl halides like benzyl and phenethyl bromides and
others. Water or oil-soluble or dispersible products are thereby
obtained. Examples of acids which can be employed to form
pharmaceutically acceptable acid addition salts include such
inorganic acids as hydrochloric acid, hydrobromic acid, sulphuric
acid and phosphoric acid and such organic acids as oxalic acid,
maleic acid, succinic acid and citric acid.
[0059] The phrase "pharmaceutical composition" refers to a
formulation of a compound and a medium generally accepted in the
art for the delivery of the biologically active compound to
mammals, e.g., humans. Such a medium includes all pharmaceutically
acceptable carriers, diluents or excipients therefore.
[0060] The phrase "pharmaceutically acceptable carrier, diluent or
excipient" as used herein includes without limitation any adjuvant,
carrier, excipient, glidant, sweetening agent, diluent,
preservative, dye/colorant, flavor enhancer, surfactant, wetting
agent, dispersing agent, suspending agent, stabilizer, isotonic
agent, solvent, or emulsifier which has been approved by the United
States Food and Drug Administration as being acceptable for use in
humans or domestic animals.
[0061] Treating" or "treatment" as used herein covers the treatment
of the disease or condition of interest, e.g., tissue injury, in a
mammal, preferably a human, having the disease or condition of
interest, and includes: (i) preventing the disease or condition
from occurring in a mammal, in particular, when such mammal is
predisposed to the condition but has not yet been diagnosed as
having it; (ii) inhibiting the disease or condition, i.e.,
arresting its development; (iii) relieving the disease or
condition, i.e., causing regression of the disease or condition; or
(iv) relieving the symptoms resulting from the disease or
condition.
[0062] As used herein, the terms "disease," "disorder," and
"condition" may be used interchangeably or may be different in that
the particular malady or condition may not have a known causative
agent (so that etiology has not yet been worked out) and it is
therefore not yet recognized as a disease but only as an
undesirable condition or syndrome, wherein a more or less specific
set of symptoms have been identified by clinicians.
[0063] As used herein, the term "%" when used without qualification
(as with w/v, v/v, or w/w) means % weight-in-volume for solutions
of solids in liquids (w/v), % weight-in-volume for solutions of
gases in liquids (w/v), % volume-in-volume for solutions of liquids
in liquids (v/v) and weight-in-weight for mixtures of solids and
semisolids (w/w), such as described in Remington's Pharmaceutical
Sciences [Troy, David B., Ed.; Lippincott, Williams and Wilkins;
21st Edition, (2005)].
[0064] The term "drug" as used in conjunction with the present
disclosure means any compound which is biologically active, e.g.,
exhibits or is capable of exhibiting a therapeutic or prophylactic
effect in vivo, or a biological effect in vitro.
[0065] The term "donor solution" or "delivery medium" comprises the
biologically active substance itself or any mixture of this
substance with a solvent, a gelling agent, a photocatalytic agent,
a carrier or adjuvant, a skin-penetrating agent, a
membrane-penetrating agent and combinations thereof. The
biologically active substance, or alternately "active ingredient"
does not have to be dissolved in a solvent but can be suspended or
emulsified in a solvent. The donor solution or delivery medium can
take the form of an aqueous or an organic liquid, a cream, a paste,
a powder or a patch.
[0066] Although not an exhaustive list, examples illustrating the
term "mammal" include human, ape, monkey, rat, pig, dog, rabbit,
cat, cow, horse, mouse, and goat Skin surfaces or membranes
according to the invention refer to those of a human or other
mammal.
[0067] The term "viscous solution" refers to a solution that has an
increased resistance to flow.
[0068] The term "cellular surface" refers to an outer layer of the
skin, a cell membrane, or tissue.
[0069] The term "transmembrane" refers to the penetration and
movement of a biologically active substance from an extracellular
environment to an intracellular environment.
[0070] The term "transocular", as used herein, refers to the
penetration and movement of a biologically active substance from an
external region of the eye of a subject to the interior region of
the eye of the subject.
[0071] The term "incoherent light" refers to electromagnetic waves
that are unorganized and propagate with different phases. The term
"pulsed incoherent light" is any incoherent light having a discrete
ON and OFF period.
[0072] In contrast, "coherent light" refers to all light rays that
are in phase and oriented in the exact same direction to produce a
concentrated beam of light. Lasers generate these types of rays and
can penetrate through materials such as solid media, including
metals (e.g., sheet metal).
[0073] The term "light emitting diode" or "(LED)" as used herein
refers to a device that generally emits incoherent light when an
electric voltage is applied across it. Most LEDs emit monochromatic
light at a single wavelength that is out of phase with each other.
According to the invention, most, if not all, types of LEDs can be
used. For example, an LED having output range from red
(approximately 700 nm) to blue-violet (approximately 350 nm) can be
used. Similarly, infrared-emitting diodes (IRED) which emit
infrared (IR) energy at 830 nm or longer can also be used.
[0074] The terms "optically clear medium" or "light pad" as used
herein refer to materials that act as a filter to all wavelengths
except those wavelengths emitted from a light source. In a
preferred embodiment of the present disclosure, the light pad is
comprised of clear poly(methyl methacrylate) or clear silicon
rubber.
[0075] The term "reflective coating or layer" as used herein is a
material that is coated on at least one surface of the light pad.
Those skilled in the art will appreciate that the reflective layer
can be a wavelength specific reflective coating (e.g., aluminum,
ZnO, silver or any reflective paint).
[0076] The term "photokinetic" as used herein refers to a change in
the rate of motion in response to light, as an increase or decrease
in motility with a change in illumination.
DETAILED DESCRIPTION
[0077] The Figures described above and the written description of
specific structures and functions below are not presented to limit
the scope of what Applicants have invented or the scope of the
appended claims. Rather, the Figures and written description are
provided to teach any person skilled in the art to make and use the
inventions for which patent protection is sought. Those skilled in
the art will appreciate that not all features of a commercial
embodiment of the inventions are described or shown for the sake of
clarity and understanding. Persons of skill in this art will also
appreciate that the development of an actual commercial embodiment
incorporating aspects of the present inventions will require
numerous implementation-specific decisions to achieve the
developer's ultimate goal for the commercial embodiment. Such
implementation-specific decisions may include, and likely are not
limited to, compliance with system-related, business-related,
government-related and other constraints, which may vary by
specific implementation, location and from time to time. While a
developer's efforts might be complex and time-consuming in an
absolute sense, such efforts would be, nevertheless, a routine
undertaking for those of skill in this art having benefit of this
disclosure. It must be understood that the inventions disclosed and
taught herein are susceptible to numerous and various modifications
and alternative forms. Lastly, the use of a singular term, such as,
but not limited to, "a," is not intended as limiting of the number
of items. Also, the use of relational terms, such as, but not
limited to, "top," "bottom," "left," "right," "upper," "lower,"
"down," "up," "side," and the like are used in the written
description for clarity in specific reference to the Figures and
are not intended to limit the scope of the invention or the
appended claims.
[0078] Computer programs for use with or by the embodiments
disclosed herein may be written in an object oriented programming
language, conventional procedural programming language, or
lower-level code, such as assembly language and/or microcode. The
program may be executed entirely on a single processor and/or
across multiple processors, as a stand-alone software package or as
part of another software package.
[0079] Applicants have created methods, apparatus, and systems for
the transcleral/transcorneal ocular delivery of biologically active
molecules and compositions to a mammal, using photokinetic delivery
methods and assemblies.
[0080] One embodiment of the invention relates to compositions for
photokinetic transcleral/transcorneal delivery, also referred to
herein as Photokinetic Ocular Drug Delivery (PODD) of one or more
biologically active substances to and through the tissues of a
patient's eyes, using preferably pulsed incoherent light or,
alternatively, regulated coherent light. The composition may
comprise a biologically active substance as the delivery
medium.
[0081] The composition may alternatively comprise a biologically
active substance and a solvent. The percent of biologically active
substance in solvent can be in the range of between 0.0001 to
99.9999% (w/v). Preferably, the biologically active substance is
present in a concentration range of between about 0.01% to about 2%
(w/v). More preferably, the biologically active substance is
present in a concentration range of between about 0.1 mg/ml to
about 10 mg/ml in the solvent or, alternatively, between about
0.01% to about 1% (w/v). Due to the high level of permeation
achieved by the methods and devices described herein, low
concentrations of a biologically active substance in solvent or in
other compositions described herein can be used for efficient
transcleral or transcorneal delivery.
[0082] The composition may instead comprise a biologically active
substance, a gelling agent and a solvent. The percent gelling agent
in a solution of biologically active substance can vary depending
on the type of gelling agent used. For example, Klucel is typically
used at 1% (w/v), Natrasol at 1.5% (w/v), Carbopol at 0.75% (w/v),
and TEA at 0.25% (w/v).
[0083] The biologically active substance of the above compositions
for use in transcleral or transcorneal administration to a subject
for therapeutic purposes may be selected from the group consisting
of chemicals, drugs, antibiotics, peptides, hormones, proteins,
DNA, RNA and mixtures thereof. Preferably, in accordance with one
aspect of the present disclosure, the biologically active
substances which may be used for transcleral/transcorneal,
non-invasive delivery to the eye of a subject are large molecules.
As used herein, the phrase "large molecules" as applied to
biologically active substances refers to those biological
substances having molecular weights of at least 100 Daltons (Da),
preferably more than about 500 Daltons (Da), more preferably more
than about 1,000 Daltons (Da), and even more preferably a molecular
weight of more than about 5,000 Daltons (Da), such as molecular
weights of about 50,000 Daltons or greater, including compounds
having molecular weights of about 100,000 Daltons (Da) or more,
such as compounds having molecular weights of about 150,000 Daltons
(Da), e.g., about 149 kDa in the case of infliximab
(REMICADE.COPYRGT.). For example, the biologically active
substances which may be therapeutically administered to a subject
using the PODD methods of the present disclosure may be large
molecules having a molecular weight ranging from about 100 Da to
about 150,000 Da, or ranging from about 500 Da to about 150,000 Da,
as well as ranges within this range, such as from about 1,000 Da to
about 130,000 Da, from about 5,000 Da to about 125,000 Da, and from
about 10,000 Da to about 100,000 Da, as well as ranges within these
ranges, such as from about 20,000 Da to about 135 Da, inclusive. In
accordance with the present disclosure, as used herein, the
molecular weight of a molecule refers to the sum of the weights of
the atoms of which it is made, typically abbreviated as "MW" or
"mw", and herein typically expressed in Daltons (Da).
[0084] The drug may be selected from the group consisting of
anti-infectives, antibiotics, antifungals, antivirals,
antineoplastics, anti-VEGFs, antineovasculars, steroids,
anti-inflammatories (including NSAIDS), immunomodulators, gases,
antioxidants, nanoparticles, genes, cytokines, peptides,
antithrombotics, nucleotides, RNAs, anti-compliment medications,
compliment modulating medications, peptides, immunoglobulins,
antibodies, antigens, anti-glaucoma medications, hormones, vitamins
(such as cyanocobalamin, vitamin B.sub.12), amino acids, silicone
liquids, heavy liquid tamponades, cellular nutrients,
anti-apoptotic agents, anticoagulants, tissue adhesives, cofactors,
coenzymes, and enzymes. In a preferred embodiment of the present
disclosure, the drug is an anesthetic, preferably lidocaine.
[0085] The compositions according to the invention may also
comprise antibiotics as the biologically active substance.
Antibiotics according to the invention are selected from the group
consisting of amoxycillin, ampicillin, penicillin, clavulanic acid,
aztreonam, imipenem, streptomycin, gentamicin, vancomycin,
clindamycin, cephalothin, erythromycin, polymyxin, bacitracin,
amphotericin, nystatin, rifampicin, tetracycline, doxycycline,
chloramphenicol, tobramycin, and zithromycin. In a preferred aspect
of this embodiment, the biologically active substance is the
antibiotic vancomycin.
[0086] The compositions according to the invention may also
comprise antivirals as the biologically active substance.
Antivirals according to the invention are selected from the group
consisting of guanosine derivatives, nucleoside phosphonates,
phosphonic acid derivatives, oligonucleotides, and combinations
thereof, as well as pharmaceutically acceptable salts, solvates,
hydrates, and derivatives thereof. In a preferred aspect of this
embodiment of the present disclosure, the antiviral is foscarnet
(FOSCAVIR.TM., Astra Zeneca), fomivirsen sodium (VITRAVENE.TM.,
Isis Pharmaceuticals), trifluridine (VIROPTIC.TM.), ganciclovir,
cidofovir, and vidarabine (Vira-A.TM., Monarch
Pharmaceuticals).
[0087] Similarly, in another embodiment of the present disclosure,
the biologically active substance is a peptide selected from the
group consisting of known biologically active peptides, including
but not limited to antibiotic peptides, antifungal peptides,
anticancer peptides, immunological and inflammatory peptides,
opioid peptides, neurotrophic peptides, and the like. In a
preferred embodiment of the present disclosure, the peptide is
insulin-like growth factor-1 (IGF-1; also known as somatomedin C or
mechano growth factor and having a molecular weight of 7649
daltons).
[0088] In further embodiments of the present disclosure, the
biologically active substance to be transsclerally delivered using
the PODD system described herein is a hormone or steroid, or a
pharmaceutically acceptable salt, solvate, hydrate, or derivative
thereof. The hormones which may be used for therapeutic
applications in accordance with this disclosure are selected from
the group consisting of methionine enkephalin acetate, leucine
enkephalin, angiotensin II acetate, .beta.-estradiol, methyl
testosterone, methyl prednisolone, corticosteroids (including
corticosone, cortisone, hydrocortisone, and aldosterone),
budenoside, progesterone, and insulin. In accordance with one
particular aspect of this embodiment, the biologically active
hormone is insulin. In accordance with another aspect of this
embodiment, the biologically active substance is the steroid
triamcinolone acetonide (TA; KENALOG.TM., Bristol Myers
Squibb).
[0089] In another embodiment of the present disclosure, the
biologically active substance to be transsclerally or
transcorneally delivered to a subject using the PODD system
described herein is a protein. The protein may be selected from the
group consisting of enzymes, non-enzymes, antibodies (including
monoclonal antibodies), and glycoproteins. In one embodiment of the
invention, the protein is a humanized antibody. In accordance with
yet another aspect of this embodiment of the present disclosure,
the biologically active substance to be transclerally or
transcorneally delivered to a subject is a fusion protein, such as
VEGF Trap-Eye (an investigational drug manufactured by Regeneron,
Tarrytown, N.Y.). In accordance with a further aspect of this
embodiment of the present disclosure, the protein is a monoclonal
antibody selected from the group consisting of adalimumab
(Humira.TM.; Abbott), bevacizumab (Avastin.TM.; Genentech),
daclizumab (Zenapax.TM.; Roche); etanercept (Enbril.TM.; Amgen);
infliximab (Remicade.TM.; Centocor); ranibizumab (LUCENTIS.RTM.;
Genentech); and rituximab (Rituxican.TM.; Genentech).
[0090] In another embodiment of the present disclosure, the
biologically active substance to be transclerally or transcorneally
delivered to a subject using the PODD system described herein is an
anticancer agent such as 5-fluorouracil (5-FU), mitomycin C,
melphalan, carboplatin, methotrexate, or colchicine, or a compound
for the treatment of neovascular (wet) age-related macular
degeneration (AMD), such as pegaptanib (MACUGEN.TM., OSI/Eyetech
and Pfizer).
[0091] Compositions according to the present disclosure can also
contain a gelling agent in combination with the biologically active
agent and/or solvent. The gelling agent may be selected from the
group consisting of hydroxyethyl cellulose, Natrasol.TM., pectines,
agar, alginic acid and its salts, guar gum, pectin, polyvinyl
alcohol, polyethylene oxide, cellulose and its derivatives,
propylene carbonate, polyethylene glycol, hexylene glycol sodium
carboxymethylcellulose, polyacrylates,
polyoxyethylene-polyoxypropylene block copolymers, pluronics, wood
wax alcohols, and tyloxapol. In a preferred embodiment of the
present disclosure, the gelling agent is hydroxypropyl
cellulose.
[0092] The compositions for therapeutic transscleral/transcorneal
delivery using the methods and devices described herein may also
comprise a solvent that is an aqueous solvent, an organic solvent,
or a mixture thereof (such as oil-in-water micro-emulsions) as
appropriate. In accordance with one embodiment, the aqueous solvent
is water. In yet another embodiment, the aqueous solvent is an
aqueous solution of ethyl lactate or propylene glycol. Preferably,
the water is HPLC grade or purified by means such as reverse
osmosis or distillation. In accordance with further embodiments of
the disclosure, the solvent is an organic solvent selected from the
group consisting of dimethylsulfoxide (DMSO) and poly(ethylene
oxide)s (PEOs).
[0093] The donor solution or delivery medium according to the
invention is comprised of a biologically active substance itself or
any mixture of a biologically active substance with a solvent, a
gelling agent, a carrier or adjuvant, a tissue-penetrating agent,
emulsifier, one or more different biologically active substances,
polymers, excipients, coatings and combinations thereof. In
essence, the biologically active substance or substances can be
combined with any combination of pharmaceutically acceptable
components to be delivered to the cellular surface by the method
described herein, e.g., photokinetic transscleral and/or
transcorneal ocular delivery. The biologically active substance
does not have to be dissolved in a solvent but can be suspended or
emulsified in a solvent. The donor solution or delivery medium can
take the form of an aqueous or an organic liquid, a cream, a paste,
a powder, or a patch. The donor solution can also comprise
microspheres or nanospheres of biologically active substances.
[0094] Turning now to the Figures, FIG. 1 illustrates an intended
application for a photokinetic transscleral and/or transcorneal
drug delivery application in accordance with the present
disclosure. FIG. 2 illustrates a closer view of the photokinetic
patch of FIG. 1, showing the attachment of the patch to the sclera
under the eyelid. FIG. 3 illustrates a top view of an exemplary
photokinetic eye patch in accordance with the present disclosure.
FIG. 4 illustrates a cross-section through the patch of FIG. 3.
FIG. 5 illustrates an exemplary photokinetic eye patch in
accordance with the present disclosure in combination with an LED
embedded in the patch material. These figures will be discussed in
combination.
[0095] In FIG. 1, a general illustration of an intended application
for photokinetic transscleral and/or transcorneal drug delivery in
accordance with aspects of the present disclosure is shown, wherein
a photokinetic transcleral drug delivery system is illustrated,
comprising a patch, a square pulse generator, and a transmission
wire connecting the two. The photokinetic patch 1 is applied to the
exterior surface of the eye of a subject, in this case a human. An
electronic pulse is generated by any suitable square wave pulse
generator 20, which may be mounted over the ear or in other
suitable manners (e.g., in a headband) proximate to the eye of the
subject to be treated. This electrical pulse signal is transmitted
to the photokinetic patch via an electric current transmitting wire
5. FIG. 2 illustrates an enlarged region of the subject's eye of
the system of FIG. 1, showing the photokinetic patch 1 applied to
the sclera 7 of the subject's eye, under the eyelid 8. The patch 1
includes a patch material, at least one LED associated with the
patch, and electrical conducting wires 4. The patch material 2 may
be any optically clear material that is flexible and soft enough to
be applied to the eye without causing physical damage to the
tissue. The patch is positioned so that the light output is
directed in the direction of the eye tissue.
[0096] FIG. 3 illustrates a top view of the photokinetic eye patch
1 shown in FIGS. 1 and 2. As illustrated therein, the optically
clear patch material 2 includes at least one LED 3 embedded within
the patch material 2, although it is envisioned that the patch may
include a plurality of LEDs, as appropriate. In the event that
there are a plurality (two or more) LEDs 3 embedded in the
material, the LEDs may be interconnected within the patch itself,
and then connected to a lead wire 5 coming from the electrical
square wave pulse generator 20. FIG. 4 illustrates a
cross-sectional view of the patch 1 of FIG. 3 taken along line A-A.
As is evident from this view, the patch is preferably manufactured
with at least a slight curvature, so as to accommodate the normal
curvature of the eye. Such curvature may be a predefined, standard
curvature, or may be individually crafted for individual patients,
depending upon their needs. As is also evident from FIG. 4, the
LEDs 3 are embedded within the patch, and are electrically
connected via communication wire 4, and are in turn connected to a
conductor lead wire 5 coming from the wave pulse generator. The
side of the patch 9 that contacts the eye, and which is opposite
the exterior face 11 of the patch, in accordance with aspects of
the present disclosure, is coated with a drug layer 6 in such a
manner that the drug within the drug layer 6 comes into contact
with the surface of the subject's eye. This drug layer 6 is
preferably positioned between the eye tissue and the LED 3, so that
the drug layer 6 receives the light generated by the LED during
operation of the apparatus, so as to allow the drug within the
layer 6 to transsclerally permeate the eye for therapeutic
purposes.
[0097] FIG. 5 illustrates an alternative arrangement of the system
of FIG. 1, wherein the photokinetic eye patch 1 includes at least
one LED 3 embedded within the patch material 2, with electrical
conducting wires 4 electrically attached to a wire in communication
with the pulse generator 5.
[0098] FIG. 6 illustrates an exemplary Franz diffusion cell
apparatus for in vitro determination of photokinetic conditions of
light wavelength and pulse rate, in accordance with the present
disclosure. Franz diffusion cells 31 are shown within a heat block
25, one (B) being shown in partial cut-away for purposes of
clarity.
[0099] The testing device illustrated in FIG. 6, in accordance with
the present disclosure, provides photokinetic transscleral and
transocular delivery of biologically active substances to a portion
of an eye by illuminating a biologically active substance with
pulsed incoherent light. Testing device can include a light source
(not shown) that illuminates a biologically active substance in
donor chamber 21 such that the biologically active substance
diffuses into the eye tissue 23 with little to no damage to the eye
tissue 23. Testing device can also be arranged such that the light
source illuminating a biologically active substance in donor
chamber 21 is horizontal or parallel to a surface on which it is
mounted.
[0100] Testing device may include an electrical driver circuit that
provides control signals to the light source such that pulsed
incoherent light is provided to the donor chamber 21. The driver
circuit may also provide control signals that control the
intensity, direction, and/or frequency of the light source. A
pulsed incoherent light advantageously and cyclically illuminates
the subject drug formulation 24 producing a period of excitation
and relaxation of the drug 24 and the eye tissue 23 which provides
photokinetic transscleral and transocular translocation of
biologically active substances within donor cell 21 into and
through the eye tissue 23.
[0101] Electronic Driver circuit may regulate an electrical signal
that turns (i.e., switches) light source ON and OFF at a particular
frequency. Such an electrical signal may be provided, for example,
by a voltage generator controlled by an electronic flasher circuit.
Alternatively, a driver circuit may itself be a voltage generator
and may produce an electrical signal to control the switching
characteristics of light source. For example, a voltage generator
coupled to light source may provide an electrical square wave to
power the light source. This square wave may have a desired ON and
OFF period such that light source provides pulsed incoherent light
with a desired pulse frequency (e.g., a square wave period of 0.5
seconds ON and a 0.5 seconds OFF would cause light source to switch
at 1 Hz or 1 cycle per second (CPS)).
[0102] The light source preferably provides incoherent light (to
reduce the possible damage done to eye tissue 23 or cause damage to
the drug 24 during the use of testing device). The light source may
be, for example, an LED, halogen light source, fluorescent light
source, natural light, or other source of light. More particularly,
the light source can be a light emitting diode (LED) (fluorescence,
350-1700 nm) or an infrared light emitting diode (ILED) or a
Mercury-Argon (253-922 nm), pulsed xenon (UV-VIS, 200-1000 nm),
deuterium (UV, 200-400 nm), deuterium/halogen (UV/VIS/NIR, 200-1700
nm) or tungsten halogen (color/VIS/NIR, 360-1700 nm) light source.
The light source preferably is operable in the range from red
(approximately 700 nm) to blue-violet (approximately 350 nm).
Similarly, infrared-emitting diodes (IREDs) that emit infrared
energy at 830 nm or longer may be used.
[0103] The light source does not have to be an incoherent light
source. In accordance with aspects of the present disclosure, the
light source may be a coherent light source such as, for example, a
laser. In that case, the driver circuit, or other regulation
circuitry, is preferably used to turn the coherent light source ON
and OFF to reduce the amount of damage to eye tissue 23 while still
photokinetically delivering a biologically active substance 24 from
the donor cell 21 into the eye tissue 23. Furthermore, a light
regulation/conversion device may be placed between a coherent light
source in the donor cell 21 to convert the coherent light to
incoherent light.
[0104] Note that a device such as an electronic driver circuit or a
controlled voltage generator is not required to pulse light source.
Alternatively, a mechanical shutter may be employed between light
source and donor cell. Such a shutter selectively OPENs and CLOSEs
such that donor cell is supplied pulsed incoherent light from light
source. The speed at which the shutter OPENs and CLOSEs determines
the frequency of the light pulsed onto the eye tissue. Filters (not
shown) may also be placed between light source and the donor cell
in order to remove, for example, light of specific wavelengths that
may damage the eye tissue or reduce photokinetic activity.
Alternatively, the light source may not need be immersed or
optically coupled with the drug solution found in donor cell. The
essential arrangement is when a drug in contact with the subject's
eye tissue is positioned to receive pulsed incoherent light from a
selected source at a selected pulse frequency.
[0105] Preferably, the wavelength of light reaching eye tissue is
chosen not only to reduce damage to the tissue, but also to
increase the photokinetic activity in donor cell (e.g., 350 nm to
450 nm). The pulse rate of such light may also be between 1.7
cycles per second (cps) and 120 cps (e.g., 24 cps). If fluorescent
light is employed as light source, it preferably has a wavelength
range from about 260 nm to about 760 nm. If ultraviolet, visible,
near infrared, or halogen light is employed as light source, the
light source preferably has a wavelength range from about 340 nm to
about 900 nm. The invention is not limited to these wavelengths.
Any method to pulse illuminate the drug that is in contact with the
eye tissue may provide the photokinetic transocular drug
delivery.
[0106] Donor chamber 21 holds a biologically active substance
(e.g., chemicals, drugs, antibiotics, peptides, hormones, proteins,
DNA, RNA and mixtures thereof). Donor chamber 21 may also include a
solvent that forms a solution with the biologically active
substance. The solution may also include a gelling agent, as
appropriate. The solvent may be an aqueous or an organic solvent.
Furthermore, eye tissue 23 may be a cellular surface which is any
layer of an eye, such as sclera, cornea or other eye tissue of a
mammal. Generally, eye tissue 23 may be any medium that allows at
least the biologically active portion drug formulation 24 contained
in the donor chamber 21 to diffuse into that medium in response to
that medium being exposed to a selected light source pulsed at a
selected pulse rate. In one embodiment, this medium is a sclera for
transscleral delivery. In another embodiment the medium is corneal
tissue for transcorneal delivery.
[0107] A clamp (not shown) may optionally be included in testing
device to couple donor chamber 21 and eye tissue 23 to the
recipient chamber 22. Drug components comprising the donor
formulation 24 placed in donor chamber 21 may be present in
recipient chamber 22 as a result of the diffusion of at least the
biologically active portion 24 of donor chamber 21 through eye
tissue 23. Also, recipient chamber 22 may contain a solvent, e.g.,
HPLC grade water, wherein diffusion of at least the biologically
active portion 24 of donor cell 21 through eye tissue 23 enters
into the solvent. Generally, the concentration of the biologically
active substance is higher in donor chamber 21 than in recipient
chamber 22.
[0108] Temperature control device, such as a heat block, is
preferably applied to at least a portion of the recipient chamber
22. Temperature directors may be included as a part of heat block
25 or coupled to the recipient chamber 22 to direct temperature
control device 25. Temperature directors (not shown) may also be
used to structurally provide support for a heat source such as a
heat bath. For example, warm water may be placed in housing defined
by temperature directors and a portion of recipient chamber 22
between temperature directors. Further to this example, a heat
source may be used to heat such water. Alternatively, a heat source
may be directly coupled to recipient chamber 22. Preferably,
temperature control device 25 heats the Franz cell assembly 31 to a
constant level. While the temperature of the solvent in recipient
chamber 22 can vary, it is preferably about 37.degree. C., human
body temperature, or about 35.5.degree. C., human eye surface
temperature. For applications requiring Franz cell assembly 31 to
be cooled, temperature control device 25 may additionally or
alternatively be a cooling source. A temperature sensor (not shown)
may be placed in, on, or about the Franz cell 31 or a heat source
such that temperature control device 25 keeps the Franz cell 31 at
a particular temperature for a particular period of time.
[0109] With continued reference to FIG. 6, stir bar 26 may be
included in recipient chamber 22 to stir any solution in recipient
chamber 22. Preferably, stir bar 26 constantly stirs the solution
in recipient chamber 22. Recipient chamber 22 may be alternatively
stirred, for example, by a shaking device. Removal of stir bar 26
would, for example, recipient chamber 22 to be easily sanitized
while reducing the design complexity of recipient chamber 22
assembly. Stir bar 26 may be connected to an electrical motor (not
shown).
[0110] Side arm port 27 may be included in recipient chamber 22 to
add or remove samples to or from recipient chamber 22 or solutions
to or from recipient chamber 22. Generally, port 27 is an aperture
into recipient chamber 22. An alternate guide tube (not shown) may
be included to form an extended port 27 such that a sample recovery
or dispersal tool can easily migrate to port 27. A cover may be
employed on port 27 such that contaminants from outside recipient
chamber 22 do not pass through port 27 when samples are being added
or removed from recipient chamber 22. In accordance with certain
aspects of the present disclosure, if a guide tube is included in
association with port 27, the guide tube is generally an adapter.
For example, if the recovery/dispersal tool is a needle, then guide
tube 27 preferably facilitates the coupling of the needle to port
27.
[0111] The Franz cell apparatuses 31 are designated to determine
passive permeation A or photokinetic permeation B into and through
eye tissues 23. The Franz cell has two chambers--the donor chamber
21 and the recipient chamber 22. Eye tissue 23 is placed between
the two chambers and sealed into place and held between the two
chambers by a clamp (not shown). The recipient chamber 22 is filled
with an aqueous solution selected to allow for chemical analytical
methods. The donor chamber 21 is filled with a drug in a
pharmacologically acceptable formulation, as described herein. The
recipient chamber 22 is constantly stirred by a magnetic stir bar
26. A portion of the recipient chamber is placed in a heat block 25
heated to a physiological temperature (about 35.5.degree. C.). At
various time points, samples are dawn from the side arm port 27 for
purposes of chemical analysis.
[0112] The passive permeation cell A provides permeation flux rates
though the scleral tissue. In the photokinetic Franz cell B, a
selected LED 28 is partially submerged within the drug formulation
24 within the donor chamber 21. The LED is driven by an external
pulse generator at a selected pulse rate and connected to the LED
electrical connectors 29. The scleral tissue 23 is positioned in
contact with and under the drug formulation 24. The drug
formulation in contact with the tissue is illuminated by the light
30 generated by the LED 28.
[0113] The photokinetic transocular drug delivery methods described
herein are useful for the therapeutic treatment of a variety of
ocular disorders by delivering a wide variety of drugs of a large
variety of molecular weight ranges into and through the scleral
tissue of the patient. Ocular diseases and disorders suitable for
therapeutic treatment with the methods and systems described herein
include but are not limited to cancer, such as primary ocular
lymphoma; diabetic retinopathy, including proliferative diabetic
retinopathy (PDR); diabetic retinoblastoma; diabetic macular edema;
macular degeneration, including "wet" (exudative) macular
degeneration and age-related macular degeneration (AMD);
intraocular edematous; uveitis, including posterior uveitis;
inflammatory diseases; retinitis; glaucoma, including neovascular
glaucoma; cicatrizing conjunctivitis; myasthenia gravis; macular
edema; choroidal neovascularization; endophthalmitis; ocular
toxoplasmosis; and proliferative vitreous retinopathy (PVR). In
accordance with aspects of the present disclosure, the transocular
drug delivery methods described herein are useful in the treatment
of diabetic retinopathy, macular edema, and diabetic
retinoblastoma. In accordance with further aspects of the present
disclosure, the transocular photokinetic ocular drug delivery
(PODD) methods and systems described herein are useful in the
treatment of glaucoma, including neovascular glaucoma. In
accordance with still further aspects of the present disclosure,
the transocular photokinetic ocular drug delivery (PODD) methods
and systems described herein are useful in the treatment of uveitis
and ocular inflammatory diseases. In accordance with another aspect
of the present disclosure, the transocular photokinetic ocular drug
delivery (PODD) methods and systems described herein are useful in
the treatment of macular degeneration, including both wet macular
degeneration and age-related macular degeneration.
[0114] In accordance with the treatment of ocular disorders and
diseases using the systems and methods described herein, the
methods of treatment for any of the diseases and disorders set
forth above, particularly glaucoma, diabetic retinopathy, uveitis,
and macular degeneration, comprise administering a therapeutically
effective amount of a compound, preferably a high-molecular weight
compound, or a pharmaceutically acceptable salt, solvate, hydrate,
racemate, or stereoisomer thereof, to a subject in need thereof
using the PODD methods described herein. For example, the instant
disclosure envisions methods for the treatment of glaucoma
comprising administering a therapeutically effective amount of a
compound, preferably a high-molecular weight compound, or a
pharmaceutically acceptable salt, solvate, hydrate, racemate, or
stereoisomer thereof, to a subject in need thereof. Similarly, the
instant disclosure envisions methods for the treatment of uveitis,
diabetic retinopathy, or macular degeneration in a patient wherein
the method comprises administering a therapeutically effective
amount of a compound, preferably a high-molecular weight compound,
or a pharmaceutically acceptable salt, solvate, hydrate, racemate,
or stereoisomer thereof, to a subject in need thereof using the
PODD methods described herein. Further, the instant disclosure
envisions methods for the treatment of VEGF-related angiogenic
diseases, particularly those selected from the group consisting of
cancer, age-related macular degeneration (AMD), and diabetic
retinopathy, wherein the method comprises administering a
therapeutically effective amount of a compound, preferably a
high-molecular weight compound, or a pharmaceutically acceptable
salt, solvate, hydrate, racemate, or stereoisomer thereof, to a
subject in need thereof using the PODD methods described
herein.
[0115] The following examples are included to demonstrate preferred
embodiments of the invention. It should be appreciated by those of
skill in the art that the techniques disclosed in the examples
which follow represent techniques discovered by the inventor(s) to
function well in the practice of the invention, and thus can be
considered to constitute preferred modes for its practice. However,
those of skill in the art should, in light of the present
disclosure, appreciate that many changes can be made in the
specific embodiments which are disclosed and still obtain a like or
similar result without departing from the scope of the
invention.
EXAMPLES
Example 1
Methotrexate Transcleral Delivery
[0116] Materials and Methods
[0117] A traditional "up and down" vertical Franz cell skin
perfusion apparatus as described above was adapted and used for
this sclera tissue permeation model. The absorption spectrum of the
test drug, methotrexate (MTX, a drug used in the treatment of
primary ocular lymphoma) was determined. Two wavelengths of light
were selected of this facilitated permeation study. Samples of the
Franz recipient solution were taken at 15, 30 and 60 minutes of
photokinetic exposure and passive controls and analyzed by
HPLC.
[0118] Instruments and Materials
[0119] Franz cells (PermeGear, Inc, Bethlehem Pa.) having an 11.28
mm diameter permeation area, 1.0 cm.sup.2 were used in the MTX
experiment. A photokinetic ocular drug delivery (PODD)-modified
Franz cell testing device was configured so that it accommodated
the placement of LEDs within the donor chamber. The cells were
placed within an aluminum block heater 35.5.degree. C. on a
magnetic stir bar setup (Custom manufactured by PermeGear, Inc,
Bethlehem Pa.).
[0120] Spectrophotometry measurements (Beckman DU 650) of
Methotrexate (Sigma Chemicals) (FIG. 7) showed a minor peak of
absorption at 370 nm in the near visible light range.
[0121] Discrete wavelength LEDs were purchased from Roithner
Lasertechnick GmbH, Vienna, Austria as follows: 351 nm, #RTL350-30;
370 nm, #RLS-UV370. Peak emitting wavelengths are .+-.10 nm at the
50% radiance output. The LEDs were driven by a square wave pulse
generator built by the investigators for this study. The adjustable
square wave pulse generator provided pulsed electrical energy set
at 24 cycles per second (CPS) with a 50% pulse duration (ON 50%,
OFF 50% of the time). Driver current to the LEDs was limited to or
slightly below the manufacturers specified drive current level to
avoid exogenous heat generation. The experimental arrangement is
shown generally in FIG. 6. As shown therein, Franz cells 31 are
adapted for sclera photokinetic permeation studies. A donor cell
contains the test drug (in this example, methotrexate (MTX)) in a
solvent formulation. The recipient cell is filled with a balance
salt solution. Samples for chemical analysis are taken from the
side arm 27 of the Franz apparatus as discussed above. Control
cells are set up the same, but without the LED. LEDs are driven by
a square wave pulse generator (not shown) at a voltage slightly
less than the manufacture's specified voltage.
[0122] Sclera: Ovine sclera was used as the subject tissue, and was
selected because ovine sclera is slightly thicker than human or pig
sclera, and so the total drug flux may be less than what could be
attained in human use. Ovine eyes were procured by enucleation
within one hour after euthanasia and placed in tissue culture
medium with antibiotics and antimycotics and refrigerated at
4.degree. C. Sclera tissue was dissected from the eyes and placed
between the donor and recipient chambers of the Franz apparatus.
Sclera was stored for a maximum of 30 hours in the tissue culture
at 4.degree. C. before the start of the experiment.
[0123] Drug Formulation: Methotrexate (MTX; (4-Amino-10-methylfolic
acid hydrate); available from Sigma-Aldrich Corp., St. Louis, Mo.)
was dissolved in a permeation enhancement carrier of water, 30%
propylene glycol, 5% Ethyl Lactate, 0.1% Azone, and 0.75%
hyaluronic acid as a gelling agent, with 0.1% neolone 850 as a
preservative. An infinite donor sink model was used wherein 0.75
grams of the drug formulation (1.875 mg of each) was placed in the
Franz donor cells. Hanks isotonic salt solution served as the Franz
recipient cell fluid.
[0124] HPLC Method: HPLC analysis was performed according to a
method developed in our lab. Briefly, a Beckman Coulter system
consisting of 125 pumps, 508 auto sampler and 168 diode array
detector was used with an XTerra RP-C18, 150.times.40 mm, 3 .mu.m
column. The analytes were eluted with a gradient mobile phase from
25-30% Methanol in HPLC grade water with 0.1% Trifluoroacetic Acid
(TFA) and flow rate of 0.7 ml/min. 32 Karat.TM. software (Beckman
Coulter, Inc.) was used for acquisition of chromatograms.
[0125] Recipient Cell Concentration Method: The Franz recipient
cell balanced salt solution was analyzed by the HPLC method for MTX
concentration.
[0126] Histology: Sclera samples were taken and placed in formalin
as follows: Normal control sclera with no exposure to drug or
light, Franz cell 60 minute control drug only exposure and Franz
cell 60 minute exposure to both drug and 350 nm LED light. Fixed
slides were evaluated for structural integrity and gross appearance
by a pathologist blinded as to the origin of the sample tissue.
[0127] Statistics: Statistical analysis was performed using one way
analysis of variance (ANOVA) with Bonferroni's correction.
Significance was accepted at p<0.05.
[0128] Results
[0129] Recovered MTX concentration from Franz cells experimental
results are expressed as drug quantity per square centimeter
(cm.sup.2) of exposed tissue over time, e.g., micrograms of MTX
recovered from the Franz recipient cell per square centimeter of
sclera at each time point (.mu.g/cm.sup.2/Time). The human eye
volume is only about 6.5 mL, so the ratio of drug permeation
surface available to the internal volume is very large compared to
transdermal drug delivery applications. This surface to volume
ratio indicates that photokinetic in vitro drug flux volumes
attained can greatly exceed the required therapeutic range of the
drugs tested, even with greater than 60 minutes of photokinetic
exposure time.
[0130] Effect of Light Wavelength on Permeation: For both
wavelengths of light tested all PODD cells showed an improvement of
MTX permeation through the scleral tissue. In the 350 nm group,
significant (p<0.05) levels of MTX were recovered at the 30 and
60 minute time points (FIG. 8). In the 370 nm group, significant
(p<0.05) levels of MTX were recovered at the 15, 30 and 60
minute time points (FIG. 9). The 370 nm group showed a much higher
flux rate at all time points when compared to the 350 nm group.
[0131] Histological Examination: Histological examination of the 60
minute PODD exposure compared to passive control revealed no
differences between the samples. The fibrous layers in all samples
were grossly intact. No zones of necrosis were found in the sclera
sample areas immediately adjacent to the portion compressed by the
Franz cell flange. The two Franz cell mounted sclera samples (60
minute passive control and the PODD) demonstrated no differences
from the normal sclera not exposed to drug or light. The structural
integrity of the sclera was observed to be grossly intact and
undamaged.
DISCUSSION
[0132] The data clearly shows that pulsed light of a specific
wavelength may facilitate methotrexate (MTX) to permeate through
ovine sclera at significantly higher flux rates when compared to
passive controls. The sharp flux rate differences between the
relatively narrow wavelengths selected (350 nm and 370 nm) for this
study further suggests the system is highly wavelength dependent
even within a narrow range.
[0133] The energy of light increases as the light wavelength
decreases in size; 350 nm light has more energy than 370 nm light.
The results demonstrate that light with a lower energy caused
significantly higher permeation rates. Thus, high light energy in
itself is not the deciding factor of permeation rates. The absence
of sclera damage under histological examination from both light
groups along with the differences in flux rates between within each
of the test groups suggests that light energy did not cause unseen
physical damage to the fibrous scleral layers that could result in
permeation pathways. One would suspect that if there was a physical
disruption of the sclera by the light itself, the higher energy 350
nm light would have higher flux rates. Additionally, incoherent
near visible light at 350-370 nm as emitted from an LED has not
been shown to cause physical damage or disruption to other
tissues.
[0134] All electronic components generate heat when a current is
applied. LEDs driven by excessive current will get hot and quickly
burn out. When driven at or slightly below the specified current,
exogenous heat is minimal. In early experiments, temperature
increases within the Franz donor cell could not be detected,
although we suspect a minor amount of heat is generated. Again, if
heat from the LED was the mechanism of increased permeation, then
the flux rate of both drugs should have been increased in all the
wavelength groups.
[0135] The use of LEDs as the light source is of convenience. Light
emitting diodes (LED) have inherent narrow wavelength emissions
based on the composition of the diode material and are available in
discrete wavelengths of emission and require no further optical
filtering. LEDs can be rapidly cycled and switched on and off with
no warm up or cool down light emission phase as in an incandescent
bulb. They are very efficient in converting electrical energy to
light energy and produce very little exogenous heat. The actual
light emitting portion of a LED is quite small. The majority of the
packaged LED is the housing/lens and electrical connections.
Therefore, the small size, inherent narrow light wavelength of
emission, and efficiency of light production per energy consumed
makes the LED an ideal choice for this system especially for the
limited area of the eye available. Other light sources could be
used if properly optically filtered and controlled for rapid cycle
operation.
[0136] Light pulse rate may affect the flux rate in the
photokinetic system. Unpublished data from early work suggests that
high pulse rates (in excess of 120 cps) actually diminish flux
rates. The selection of the 24-100 cycles per second pulse rate is
based on the inventor's prior data of extensive photokinetic
transdermal Franz cell testing of various low molecular weight
drugs, such as described in U.S. Pat. No. 7,458,982 B2.
[0137] The selection of Hanks balanced salt solution in the Franz
recipient cell rather than HPLC grade water was necessary due to
the ability of the sclera membrane to regulate osmolarity across
this membrane.
[0138] Although the total MTX flux did not reach a therapeutic
level of 400 .mu.g in this first attempt, various strategies can be
employed to increase flux rates across the sclera barrier membrane
such as: optimization of drug carrier/chemical permeation
enhancement, increasing the drug concentration in the topical
formulation, increasing the exposure time of the drug on the
membrane and increasing the exposed transport area.
Conclusion
[0139] The in vitro model demonstrates that pulsed incoherent light
of a selected wavelength directed onto a solution of methotrexate
applied to ovine sclera can be used to facilitate transscleral
permeation. The transscleral flux rate in the PODD system appears
to be wavelength dependent as determined by spectrophotometry
absorption of a subject drug. The PODD system did not damage or
alter the sclera exposed to light energy at the wavelengths and
intensity used herein. The PODD system may be used as an
alternative for needle injection into the eye.
Example 2
Delivery of Insulin
[0140] Two pertinent ocular drugs were selected for testing the
hypotheses. Methotrexate (MW=454 Daltons) is used for the treatment
of primary ocular lymphoma. Insulin (MW=5808 Daltons, 5.808 kDa)
and insulin like growth factors have been implicated as a possible
preventive treatment for diabetic retinopathy. The transscleral
delivery of methotrexate has been described in Example 1,
above.
[0141] A traditional "up and down" vertical Franz cell (11.28 mm
diameter permeation area, 1.0 cm.sup.2) perfusion apparatus (FIG.
6) was adapted and used for this sclera tissue permeation model.
PODD modified Franz cell testing device was configured so that it
accommodated the placement of the selected discreet wavelength LEDs
within the donor chamber. Discrete LEDs at 351 nm and 370 nm were
used for the MTX study and 405 nm and 450 nm for the insulin study
(peak emitting wavelengths at .+-.10 nm at the 50% radiance
output). The LEDs were driven by a square wave pulse generator set
at 24 cycles per second (CPS) with a 50% pulse duration.
[0142] Ovine eyes were procured by enucleation within one hour
after euthanasia and placed in tissue culture medium with
antibiotics and antimycotics and refrigerated at 4.degree. C.
Sclera tissue was dissected from the eyes and placed between the
donor and recipient chambers of the Franz apparatus within 30 hours
of enucleation.
[0143] Insulin at a concentration of 200 IUs/mL was dissolved in a
drug carrier comprised of water, 30% propylene glycol, 5% ethyl
lactate, 0.1% Azone, 0.75% hyaluronic acid as a gelling agent with
0.1% neolone 850 as a preservative. 0.75 grams of the drug
formulation was placed in the Franz donor cells. Hanks isotonic
salt solution served as the Franz recipient cell fluid.
[0144] Samples of the Franz recipient solution were taken at 15, 30
and 60 minutes of photokinetic exposure and passive controls and
analyzed by HPLC for MTX concentration and expressed as
.mu.g/cm.sup.2/Time. Samples for insulin were taken at 24 hours and
tested by ELISA methodology and expressed as microunits
insulin/cm.sup.2/24 hours. The experimental arrangement is shown in
FIG. 6.
[0145] Normal control sclera with no exposure to drug or light,
Franz cell 60 minute control drug only exposure and Franz cell 60
minute exposure to both drug and 350 nm LED light were taken and
placed in formalin. Fixed slides were evaluated for structural
integrity and gross appearance by a pathologist masked as to the
origin of the sample tissue.
[0146] Results
[0147] For both wavelengths of light tested in the insulin
experiments, all PODD cells showed an improvement of insulin
permeation through the scleral tissue vs. controls. In both light
groups, significant (p<0.05) levels of insulin was recovered at
the 24 hour time point (FIG. 10). The 450 nm PODD group showed 7
times higher flux rate while the 405 nm group showed a 2 times
higher flux rate vs. controls. Histological examination of the 24
hour 405 nm PODD exposure compared to the passive control and
normal sclera not exposed to drug or light revealed no differences
between the samples. As was the case in the experiment with
methotrexate, the structural integrity of the sclera was observed
to be grossly intact and undamaged.
[0148] Discussion
[0149] The data clearly shows that pulsed light of a specific
wavelength may facilitate insulin to permeate through ovine sclera
at significantly higher flux rates when compared to passive
controls. The sharp flux rate differences between the relatively
narrow wavelengths selected (405 and 450 nm for insulin) for this
study further suggests the system is highly wavelength dependent
even within a narrow wavelength range.
[0150] The results demonstrate that light with a lower energy (370
nm vs. 350 nm and 450 nm vs. 405 nm) caused significantly higher
permeation rates. Thus, high light energy in itself is not the
deciding factor of permeation rates. The absence of sclera damage
under histological examination from the insulin 405 nm light group
along with the differences in flux rates between within each of the
test groups suggests that light energy did not cause unseen
physical damage to the fibrous scleral layers that could result in
permeation pathways. Additionally, incoherent near visible light in
the 405-450 nm visible range as emitted from an LED has not been
shown to cause physical damage or disruption to other tissues at
the emitting intensities and exposure times used herein.
[0151] The use of LEDs as the light source is of convenience. Light
emitting diodes (LED) have inherent narrow wavelength emissions
based on the composition of the diode material and are available in
discrete wavelengths of emission and require no further optical
filtering. LEDs can be rapidly cycled and switched on and off with
no warm up or cool down light emission phase as in an incandescent
bulb. They are very efficient in converting electrical energy to
light energy and produce very little exogenous heat. The actual
light emitting portion of a LED is about 300 microns square the
remainder is packaging. Therefore, the small size, inherent narrow
light wavelength of emission, and efficiency of light production
per energy consumed makes the LED an ideal choice for this system
especially for the available limited application area of the
eye.
[0152] Various strategies can be employed to increase total flux
rates across the sclera barrier membrane such as: optimization of
drug carrier/chemical permeation enhancement, increasing the drug
concentration in the topical formulation, increasing the exposure
time of the drug on the membrane and increasing the exposed
transport area. The available accessible sclera of a human eye is
about 4-6 cm.sup.2. Insulin and insulin like growth factor
therapeutic dose requirements are likely to be very small but with
frequent administrations.
[0153] Recent photokinetic transdermal permeation studies by the
Applicants have demonstrated significant flux rates of high
molecular weight hyaluronic acid (4500 kDaltons) through intact
human skin under similar photokinetic conditions. Scleral tissue is
more permeable than human skin. The practical upper molecular
weight limit with the PODD system is unknown and may be determined
by the specific molecular configuration rather than molecular
weight per se.
Conclusion
[0154] The in vitro model demonstrates that pulsed incoherent light
of a selected wavelength directed onto a solution of methotrexate
or insulin applied to ovine sclera can be used to facilitate
transscleral permeation without damaging the scleral tissue or
chemically altering the drug.
Example 3
Transcleral Insulin Delivery of High Molecular Weight Drugs
[0155] Using the same procedures as set out above, and the
apparatus of FIG. 6, scleral tissue permeation determinations of
methotrexate over a short time period, as well as the scleral
tissue permeation of vancomycin (1 mg/mL), insulin, Insulin Like
Growth Factor-1 (IGF-1), Avastin.TM. (bevacizumab; Genentech, San
Francisco, Calif.), and hyaluronic acid (HA) were conducted. High
molecular weight hyaluronic acid (4500 kDa in size) was selected as
a test compound because the sodium salt of hyaluronic acid (SH) is
a high molecular weight biopolymer made of repeating disaccharide
units of glucuronic acid and N-acetyl-.beta.-glucosamine, and which
is present in the vitreous body and the aqueous humor. Hyaluronic
acid is a natural polymer which, due to its water retaining
capability, binds to cell membranes and can therefore be considered
to be a putative vehicle for controlled ocular delivery (Durrani,
et al., Int. J. Pharm., Vol. 118 (2), p. 243-250 (1995)). The
results are shown in FIGS. 11-16, and are summarized in FIG. 17. As
can be seen from FIG. 17, significant transscleral flux is observed
with molecules ranging from about 450 Daltons (methotrexate) to
molecules with molecular weights of about 4500 K Da (hyaluronic
acid, HA). In addition to the significant and therapeutic
transcleral fluxes illustrated by the methods and apparatus of the
present disclosure, the present photokinetic system significantly
increases the intrascleral deposition of compounds as well. This in
turn allows for the sclera itself to become a depot for extended
drug release into the intravitreal space, as well as the eye
circulation.
Example 4
Transcleral Insulin Delivery Rabbit Model
[0156] A proof-of-concept experiment was conducted for the PODD
system of the present disclosure with a rabbit ocular drug delivery
model using a fluorescent labeled human insulin molecule as the
test drug for a 60-minute photokinetic exposure. Exogenous human
insulin can be differentiated from the endogenous rabbit insulin;
the human insulin FITC (fluorescein isothiocyanate) fluorescent tag
further allows for tracking of the drug within the tissues.
FITC-labeled human insulin (5733 Daltons in size, available from
Invitrogen Corporation, Carlsbad, Calif. as insulin modified at the
N-terminus of the B-chain with an FITC conjugate/tag) was used as a
test drug for transocular applications, as the ELISA analytical
methods are widely available and accepted to provide a quantitative
as well as a functional assay for the molecule. Franz permeation
cells as described herein were utilized to define functional
photokinetic parameters of light wavelength and pulse rate in vitro
prior to the animal study.
[0157] In this series, rabbits were fitted with transscleral
photokinetic device, such as shown in FIG. 1 of this disclosure,
for one hour. One eye of the test rabbit was exposed to the
topically applied insulin, 4 micro-units/mL in a suitable drug
carrier formulation under an adapted photokinetic device using 450
nm LED light pulsed at 100 CPS for one hour, applied to a 2
cm.sup.2 area of sclera. Images were taken of the posterior optic
disc, the area where the retina, optic nerve and blood vessels come
together on the posterior segment of the eye. These results are
shown in FIGS. 18A, 18B, and 18C, with FIG. 18A illustrating the
fluorescence baseline image, FIG. 18B illustrating an IR baseline
image, and FIG. 18C illustrating the fluorescence image after 1
hour of PODD. These rabbit optic disc images demonstrate that the
fluorescent tagged human insulin administered with the PODD system
of the present system reached the posterior segment of the rabbit's
eye. The contralateral eye showed no fluorescence. Passive
permeation in other rabbits with the same experimental setup did
not show fluorescence in the optic disc.
[0158] After treatment for one hour with the transscleral
photokinetic device described herein, and after the images in FIGS.
18A-18C were taken, the animals were sacrificed and tissues and
fluids were taken for quantitative analysis. The tissues from the
photokinetic exposed eye and the contralateral eye that were
assayed for human insulin concentration. A passive permeation
control animal without light exposure but under otherwise similar
conditions was also assayed. The results of three concentration of
human FITC labeled insulin in the PODD device vs. passive
permeation of 4 mU/mL in the various fluids and tissues of the
rabbit eye after 60 minute exposure are presented in FIGS. 19A-19F,
and in Table 1, below. Although the ELISA analytical test method
employed is specific for human insulin, there is some cross
reactivity with rabbit insulin ("No Ins" in the Figures) as the kit
contains rabbit proteins as preservatives. A small quantity of
human insulin was also found in the untreated contralateral eye
transferred by the blood circulation, as also evidenced in the
figures.
TABLE-US-00001 TABLE 1 Insulin (.mu.U/mL) Insulin (.mu.U/gram
Tissue/mg Protein) Vitreous Aqueous RPE Neural Humor Humor Sclera
Cornea Choroid Retina Photokinetic exposure 118 114 1498 1500 31 28
Photokinetic Contralateral 6 40 98 22 3.75 2.5 Passive Delivery 4 2
200 200 0.89 1.3 Passive Contralateral 2 2 56 22 0.65 0.98
[0159] In view of the results shown in Table 1, this test
demonstrated the feasibility of the photokinetic transcleral and/or
transcorneal drug delivery system as described herein. The
photokinetic transcleral delivery provided drug concentrations
within the several ocular compartments.
[0160] Other and further embodiments utilizing one or more aspects
of the inventions described above can be devised without departing
from the spirit of Applicant's invention. Further, the various
methods and embodiments of the disclosure can be included in
combination with each other to produce variations of the disclosed
methods and embodiments. Discussion of singular elements can
include plural elements and vice-versa.
[0161] The order of steps can occur in a variety of sequences
unless otherwise specifically limited. The various steps described
herein can be combined with other steps, interlineated with the
stated steps, and/or split into multiple steps. Similarly, elements
have been described functionally and can be embodied as separate
components or can be combined into components having multiple
functions.
[0162] The inventions have been described in the context of
preferred and other embodiments and not every embodiment of the
invention has been described. Obvious modifications and alterations
to the described embodiments are available to those of ordinary
skill in the art. The disclosed and undisclosed embodiments are not
intended to limit or restrict the scope or applicability of the
invention conceived of by the Applicants, but rather, in conformity
with the patent laws, Applicants intend to fully protect all such
modifications and improvements that come within the scope or range
of equivalent of the following claims.
* * * * *