IP Library › Granted Patent US 12,599,577
Granted Patent B2
US 12,599,577 · App. 17/281,647 · Granted Apr 14, 2026

Thermoresponsive gel eye drop for ocular delivery of cysteamine

Inventors: Morgan Virginia Fedorchak (Mars, PA); Steven R. Little (Allison Park, PA); Joel S. Schuman (New York, NY)
Assignee: UNIVERSITY OF PITTSBURGH—OF THE COMMONWEALTH SYSTEM OF HIGHER EDUCATION
A61K31/145A61K9/0048A61K9/06A61K9/1647A61K9/1694A61K41/0028A61K47/32A61P27/02
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12,599,577
App. No.
17/281,647
Granted
Apr 14, 2026
Kind
B2
Abstract

This document provided ocular delivery systems for treatment of cystinosis as well as methods for making such ocular delivery systems and methods for using such ocular delivery systems. For example, ocular delivery systems designed to include spray-dried, cysteamine-loaded microparticles suspended in a thermoresponsive gel are provided herein.

Claims (18)

1 . An ocular delivery system for cysteamine, comprising:

a thermoresponsive gel comprising poly(N-isopropyl acrylamide) (PNIPAAm); and

a plurality of spray-dried microparticles comprising a biodegradable polymer and cysteamine or a pharmaceutically acceptable salt thereof, wherein said biodegradable polymer comprises poly(lactic-co-glycolic acid) (PLGA),

wherein at least 90 percent of said cysteamine or said pharmaceutically acceptable salt thereof is maintained within said ocular delivery system for at least seven weeks at 25° C.

2 . The ocular delivery system of claim 1 , wherein the biodegradable polymer comprises polyglycolide (PGA), poly(lactic acid) (PLA), poly(lactic-co-glycolic acid) (PLGA), or any combination thereof.

3 . The ocular delivery system of claim 1 , wherein the cysteamine or the pharmaceutically acceptable salt thereof is homogeneously dispersed within the spray-dried microparticles.

4 . The ocular delivery system of claim 1 , wherein the spray-dried microparticles have a volume average diameter within a range of from 200 nm to 10 μm.

5 . The ocular delivery system of claim 1 , wherein the spray-dried microparticles comprise from 10-20 wt % cysteamine or an amount of a pharmaceutically acceptable salt of cysteamine sufficient to provide 10-20 wt % cysteamine.

6 . The ocular delivery system of claim 1 , wherein the PLGA has a weight average molecular weight within a range of 4-80 kDa.

7 . The ocular delivery system of claim 1 , wherein the ocular delivery system comprises from 0.001 mg to 0.5 mg of the spray-dried microparticles per microliter of the ocular delivery system.

8 . An ocular delivery system for cysteamine made by a process comprising:

providing a liquid feedstock comprising cysteamine or a pharmaceutically acceptable salt thereof, a biodegradable polymer, and a solvent, wherein the biodegradable polymer comprises poly(lactic-co-glycolic acid) (PLGA);

directing the liquid feedstock to a spray-drying apparatus comprising a drying chamber comprising an inlet and an outlet, a nozzle coupled to the inlet, a spray gas source coupled to the nozzle, a separator coupled to the outlet of the drying chamber, and an aspirator coupled to the separator;

atomizing the liquid feedstock into droplets as the liquid feedstock flows through the nozzle and into the drying chamber;

removing at least a portion of the solvent from the droplets in the drying chamber, thereby forming a plurality of spray-dried microparticles, wherein the spray-dried microparticles comprise a solid dispersion of the cysteamine, or the pharmaceutically acceptable salt thereof, and the biodegradable polymer;

collecting the spray-dried microparticles; and

dispersing the spray-dried microparticles in a thermoresponsive gel comprising poly(N-isopropyl acrylamide) (PNIPAAm) to form an ocular delivery system for cysteamine,

wherein at least 90 percent of said cysteamine or said pharmaceutically acceptable salt thereof is maintained within said ocular delivery system for at least seven weeks at 25° C.

Assignments (2)
CORRECTIVE ASSIGNMENT TO CORRECT THE FIRST ASSIGNOR'S NAME PREVIOUSLY RECORDED AT REEL: 56936 FRAME: 793. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Recorded Sep 22, 2025
From: DILEO, MORGAN VIRGINIA; LITTLE, STEVEN R.; SCHUMAN, JOEL S.
To: UNIVERSITY OF PITTSBURGH - OF THE COMMONWEALTH SYSTEM OF HIGHER EDUCATION
Reel/Frame 072924/0713 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 21, 2021
From: FEDORCHAK, MORGAN VIRGINIA; LITTLE, STEVEN R.; SCHUMAN, JOEL S.
To: UNIVERSITY OF PITTSBURGH - OF THE COMMONWEALTH SYSTEM OF HIGHER EDUCATION
Reel/Frame 056936/0793 →
Continuity (2)
Provisional Application 62768295 · Nov 16, 2018
Related Publication 20210369649A1 · Dec 2, 2021
References Cited (130)
US 5837226A · Jungherr et al. · 1998 [cited by applicant]
US 6264971B1 · Darougar et al. · 2001 [cited by applicant]
US 6656460B2 · Benita et al. · 2003 [cited by applicant]
US 7060299B2 · Alavattam et al. · 2006 [cited by applicant]
US 7589057B2 · Chang et al. · 2009 [cited by applicant]
US 8298569B2 · Philips et al. · 2012 [cited by applicant]
US 8492334B2 · Lavik et al. · 2013 [cited by applicant]
US 8980248B2 · Shoichet et al. · 2015 [cited by applicant]
US 9018006B2 · Stepkowski et al. · 2015 [cited by applicant]
US 9056045B2 · Hughes et al. · 2015 [cited by applicant]
US 9655862B2 · Mousa · 2017 [cited by applicant]
US 9757276B2 · Penhasi · 2017 [cited by applicant]
US 9937256B2 · Knipe et al. · 2018 [cited by applicant]
US 9937278B2 · Steinberg et al. · 2018 [cited by applicant]
US 10376592B2 · Acharya et al. · 2019 [cited by applicant]
US 10624865B2 · Pathak · 2020 [cited by applicant]
US 10980882B2 · Kang-Mieler et al. · 2021 [cited by applicant]
US 11246838B2 · Fedorchak et al. · 2022 [cited by applicant]
US 11266608B2 · Kang-Mieler et al. · 2022 [cited by applicant]
US 20010049369A1 · Jablonski et al. · 2001 [cited by applicant]
US 20020197300A1 · Schultz et al. · 2002 [cited by applicant]
US 20060018911A1 · Ault-Riche et al. · 2006 [cited by applicant]
US 20060173060A1 · Chang et al. · 2006 [cited by applicant]
US 20060235084A1 · Heller et al. · 2006 [cited by applicant]
US 20060246145A1 · Chang et al. · 2006 [cited by applicant]
US 20090252781A1 · Sawhney et al. · 2009 [cited by applicant]
US 20100209478A1 · Sawhney et al. · 2010 [cited by applicant]
US 20100261646A1 · Lavik et al. · 2010 [cited by applicant]
US 20110189291A1 · Yang et al. · 2011 [cited by applicant]
US 20110206773A1 · Lavik et al. · 2011 [cited by applicant]
US 20120040397A1 · Luo et al. · 2012 [cited by applicant]
US 20120148676A1 · Little · 2012 [cited by applicant]
US 20120156176A1 · Fujimoto et al. · 2012 [cited by applicant]
US 20120231072A1 · Kang-Mieler et al. · 2012 [cited by applicant]
US 20130189230A1 · Shoichet et al. · 2013 [cited by applicant]
US 20140086975A1 · Sinko et al. · 2014 [cited by applicant]
US 20140086995A1 · Ratner et al. · 2014 [cited by applicant]
US 20140271863A1 · Anderson et al. · 2014 [cited by applicant]
US 20140343413A1 · Jolek et al. · 2014 [cited by applicant]
US 20140343476A1 · Penhasi · 2014 [cited by applicant]
US 20150037422A1 · Kaplan et al. · 2015 [cited by applicant]
US 20150087671A1 · McClain et al. · 2015 [cited by applicant]
US 20150140106A1 · Mousa · 2015 [cited by applicant]
US 20150374633A1 · Fedorchak · 2015 [cited by examiner]
US 20160058698A1 · Mayadunne et al. · 2016 [cited by applicant]
US 20160166504A1 · Jarrett et al. · 2016 [cited by applicant]
US 20160206741A1 · Knipe et al. · 2016 [cited by applicant]
US 20170087248A1 · Kang-Mieler et al. · 2017 [cited by applicant]
US 20170189546A1 · Bidwell, III et al. · 2017 [cited by applicant]
US 20170348254A1 · O'Neil · 2017 [cited by examiner]
US 20190046479A1 · Pathak · 2019 [cited by applicant]
US 20190099365A1 · Fedorchak et al. · 2019 [cited by applicant]
US 20200246179A1 · Peyman · 2020 [cited by applicant]
US 20200360282A1 · Fedorchak et al. · 2020 [cited by applicant]
US 20200383928A1 · Kang-Mieler et al. · 2020 [cited by applicant]
US 20220202705A1 · Fedorchak et al. · 2022 [cited by applicant]
US 20220211632A1 · Fedorchak et al. · 2022 [cited by applicant]
WO WO2011106702 · 2011 [cited by applicant]
WO WO2012044952 · 2012 [cited by applicant]
WO WO2012169972 · 2012 [cited by applicant]
WO WO2014074823 · 2014 [cited by applicant]
WO WO2014138085 · 2014 [cited by applicant]
WO WO2015001087 · 2015 [cited by applicant]
WO WO2017165449 · 2017 [cited by applicant]
WO WO2018206749 · 2018 [cited by applicant]
Luaces-Rodriguez, A., et al., Cysteamine polysaccharide hydrogels: Study of extended ocular delivery and biopermanence time by PET imaging, Jun. 19, 2017, Int. J. Pharmaceutics, vol. 528, 714-722. (Year: 2017). [cited by examiner]
Wan, F., et al., Modulating protein release profiles by incorporating hyaluronic acid into PLGA microparticles via a spray dryer equipped with a 3-fluid nozzle, May 28, 2014, Pharm. Res., vol. 31, 2940-2951. (Year: 2014… [cited by examiner]
Shams et al., “Treatment of corneal cystine crystal accumulation in patients with cystinosis,” Clin. Ophthalmol, Oct. 2014, 8:2077-2084. [cited by applicant]
Aburahma et al., “Biodegradable ocular inserts for sustained delivery of brimonidine tartarate: preparation and in vitro/in vivo evaluation,” AAPS PharmSciTech, Dec. 2011, 12(4):1335-1347. [cited by applicant]
Babiuch, retrieved from the retinal physician website: www.retinalphysician.com/issues/2017/june-2017/ new-monoclonal-antibody-treatments-in-retina on Aug. 19, 2019, 4 pages. [cited by applicant]
Bald et al., “2-Chloro-1-Methylquinolinium Tetrafluoroborate as an Effective and Thiol Specific UV-Tagging Reagent for Liquid Chromatography,” J. Liq. Chromatogr. Relat. Technologies, 2001, 24(9):1323-1339. [cited by applicant]
Berge et al., “Pharmaceutical salts,” J. Pharm. Sci., 66(1):1-19, Jan. 1977. [cited by applicant]
Chang et al., “Biodegradable PLGA-based Drug Delivery Systems for Modulating Ocular Surface Disease under Experimental Murine Dry Eye,” J. Clin. Exp. Ophthamol., 2(11): 13 pages, Nov. 1, 2011. [cited by applicant]
Chen et al., “Selection and analysis of an optimized anti-VEGF antibody: crystal structure of an affinity-matured Fab in complex with antigen,” J. Mol. Bio., 293(4):865-81, Nov. 1999. [cited by applicant]
Cui et al., “New Hydrolysis-Dependent Thermosensitive Polymer for an Injectable Degradable System,” Biomacromolecules, 8(4):1280-1286, Apr. 2007. [cited by applicant]
Derwent and Mieler, “Thermoresponsive hydrogels as a new ocular drug delivery platform to the posterior segment of the eye,” Transactions of the American Ophthalmological Society, 106:206-214, Dec. 2008. [cited by applicant]
Doiron et al., “Preparation and initial characterization of biodegradable particles containing gadolinium-DTPA contrast agent for enhanced MRI,” Proc. Nat. Acad. Sci. USA, Nov. 11, 2008, 105(45):17232-17237. [cited by applicant]
Fedorchak et al., “28-day intraocular pressure reduction with a single dose of brimonidine tartrate-loaded microspheres,” Experimental Eye Research, vol. 125, 210-216, Jun. 28, 2014. [cited by applicant]
Fedorchak et al., “28-Day Ocular Delivery of Brimonidine Tartrate from Rationally Designed Degradable Microparticles in a Rabbit Model,” presentation delivered at AIChE annual meeting Oct. 31, 2012. [cited by applicant]
Fedorchak et al., “28-Day Ocular Delivery of Brimonidine Tartrate from Rationally Designed Degradable Microparticles in a Rabbit Model,” presentation delivered at Society for Biomaterials Oct. 4, 2012. [cited by applicant]
Fedorchak et al., “Advanced Controlled Release Systems for Next Generation Ophthalmic Therapy,” presentation delivered at Gordon Research Conference Mar. 22, 2012. [cited by applicant]
Fedorchak et al., “Combating Blindness with Convenient and Comfortable Glaucoma Treatments,” presentation delivered at ARVO annual meeting May 4, 2012. [cited by applicant]
Fedorchak et al., “Combating Blindness with Convenient and Comfortable Glaucoma Treatments,” presentation delivered at McGowan Institute for Regenerative Medicine annual retreat Mar. 5, 2012. [cited by applicant]
Friedman et al., “Prevalence of open-angle glaucoma among adults in the United States,” Arch. Ophthalmol., Apr. 2004, 122(4):532-538. [cited by applicant]
Fujimoto et al., “Synthesis, Characterization and Therapeutic Efficacy of a Biodegradable, Thermoresponsive Hydrogel Designed for Application in Chronic Infarcted Myocardium,” Biomaterials, 30(26):4357-4368, Sep. 2009. [cited by applicant]
Gao et al., “A Microparticle/Hydrogel Combination Drug-Delivery System for Sustained Release of Retinoids,” Investigative Ophthamology & Visual Science, 53:10, 6314-6323, Sep. 2012. [cited by applicant]
Ghate et al., “Barriers to Glaucoma Drug Delivery,” J. Glaucoma, Mar. 2008, 17(2):147-156. [cited by applicant]
Gu et al., “Controlled release of recombinant human nerve growth factor (rhNGF) from poly [(lactic acid)-co-(glycolic acid)]microspheres for the treatment of neurodegenerative disorders,” Polymer International, 56( 10):… [cited by applicant]
Guan et al., “Protein-reactive, Thermoresponsive Copolymers With High Flexibility and Biodegradability,” Biomacromolecules, 9(4):1283-92, Apr. 2008. [cited by applicant]
Hermann et al., “Electronic compliance monitoring of topical treatment after ophthalmic surgery,” Int. Ophthalmol., Apr. 7, 2010, 30:385-390. [cited by applicant]
Hu et al., “Controlled Release Bevacizumab in Thermoresponsive Hydrogel Found to Inhibit Angiogenesis,” Biomed. Mater. Eng., 24:1941-50, 2014. [cited by applicant]
Ibrahim et al., “Novel Topical Ophthalmic Formulations for Management of Glaucoma,” Pharmaceutical Research, 30(11): 2818-2831, Nov. 15, 2013. [cited by applicant]
Jimenez et al., “A sustained release cysteamine microsphere/thermoresponsive gel eyedrop for corneal cystinosis improves drug stability,” Drug Deliv. Transl. Research, Feb. 4, 2021, 11(5):2224-2238. [cited by applicant]
Karamanos et al., “Development of an HPLC method for determining the alpha2-adrenergio receptor agonist brimonidine in blood serum and aqueous humor of the eye,” Biomed. Chromatogr., 1999, 13:86-88. [cited by applicant]
Knight et al., “Sustained drug delivery in glaucoma,” Current Opinion in Ophthamology, 25(2): 112-117, Mar. 2014. [cited by applicant]
Kusmierek et al., “Measurement of reduced and total mercaptamine in urine using liquid chromatography with ultraviolet detection,” Biomed. Chromatography, Jan. 18, 2008, 22(4):441-445. [cited by applicant]
Lambiase et al., “Experimental and clinical evidence of neuroprotection by nerve growth factor eye drops: Implications for glaucoma,” PNAS, 106(32): 13469-13474, Aug. 11, 2009. [cited by applicant]
Lee and Vernon, “In Situ-Gelling, Erodible N-isopropylacrylamide Copolymers,” Macromol. Biosci., 5(7):629-635, Jul. 2005. [cited by applicant]
MacCallum et al., “Antibody-antigen Interactions: Contact Analysis and Binding Site Topography,” J. Mol. Biai., 262(5):732-45, Oct. 1996. [cited by applicant]
Na et al., Langmuir 2010; 26:11165-11169. [cited by applicant]
Nanjawade et al., “In situ-forming hydrogels for sustained ophthalmic drug delivery,” J. Control Release., 122(2):119-34, Sep. 2007. [cited by applicant]
Nussenblatt et al. Retina, 2013; 30:1579-1587. doi:10.1097/IAE.0b013e3181e7878e. [cited by applicant]
Pascual-Camps et al. J. Ophthal. Inflann. Infect. 2014; 4:26. www.joii-journal.conn/content/4/1/26. [cited by applicant]
PCT International Preliminary Report on Patentability in International Appln. No. PCT/US2019/062028, dated May 18, 2021, 6 pages. [cited by applicant]
PCT International Search Report and Written Opinion in International Appln. No. PCT/US2019/062028, dated Mar. 19, 2020, 10 pages. [cited by applicant]
Pescina et al., “Effect of pH and penetration enhancers on cysteamine stability and trans-corneal transport,” Eur. J. Pharm. Biopharmaceutics, Oct. 2016, 107: 171-179. [cited by applicant]
Rudikoff et al., “Single amino acid substitution altering antigen-binding specificity.” Proc. Natl. Acad. Sci. U.S.A., 79(6):1979-1983, Mar. 1982. [cited by applicant]
Sánchez et al., “Development of biodegradable microspheres and nanospheres for the controlled release of cyclosporin A,” Int. J. Pharmaceutics, Oct. 15, 1993, 99(2-3):263-273. [cited by applicant]
Shanbhag et al., “Macrophage/particle interactions: effect of size, composition and surface area,” J. Biomed. Mater. Res., Jan. 1994, 28(1):81-90. [cited by applicant]
Turturro et al., “The effects of cross-linked thermo-responsive PNIPAAm-based hydrogel injection on retinal function,” Biomaterials, 32(14):3620-6, May 2011. [cited by applicant]
Wang et al., “Novel Thermosensitive Hydrogel Injection Inhibits Post-Infarct Ventricle Remodelling,” Eur. J. Heart Fail, 11(1):14-19, Jan. 2009. [cited by applicant]
Wang et al., “Synthesis, Characterization and Surface Modification of Low Moduli Poly(ether Carbonate Urethane)ureas for Soft Tissue Engineering,” Acta. Biomater., 5(8):2901-12, Oct. 2009. [cited by applicant]
Wang et al., “The nerve growth factor signaling and its potential as therapeutic target for glaucoma.” BioMed Research International, Aug. 31, 2014. [cited by applicant]
Wikipedia.org [online], “Cysteamine,” dated Sep. 7, 2018, retrieved from URL<https://en.wikipedia.org/w/index.php?title=Cysteamine&oldid=858431558>, 5 pages. [cited by applicant]
Wikipedia.org [online], “Freeze drying,” dated Nov. 6, 2018, retrieved from URL<https://en.wikipedia.org/w/index.php?title=Freeze-drying&oldid=924871987>, 12 pages. [cited by applicant]
Wu et al., “Humanization of a murine monoclonal antibody by simultaneous optimization of framework and CDR residues,” J. Mol. Biol., 294(1):151-162, Nov. 1999. [cited by applicant]
Wu et al., “Toward the development of partially biodegradable and injectable thermoresponsive hydrogels for potential biomedical applications,” ACS Appl. Mater. Interf., 1(2):312-327, Feb. 2009. [cited by applicant]
Xu et al. Macromolecules, 2007; 40:9103-9110. [cited by applicant]
Yang et al., “Hybrid Dendrimer Hydrogel/PLGA Nanoparticle Platform Sustains Drug Delivery for One Week and Antiglaucoma Effects for Four Days Following One-Time Topical Administration,” ACS Nano, 6(9): 7595-7606, Aug. 9… [cited by applicant]
Zhang and Zhuo, “Synthesis and in vitro drug release behavior of amphiphilic triblock copolymer nanoparticles based on poly (ethylene glycol) and polycaprolactone,” Biomaterials, 26(33):6736-42, Nov. 2005. [cited by applicant]
Zhang et al., “Absolute quantification of poly(dl-lactide-co-glycolide) in microspheres using quantitative 1H NMR spectroscopy,” J. Pharm. Biomed. Analysis, Nov. 30, 2017, 146:273-278. [cited by applicant]
Zweers et al., “Release of anti-restenosis drugs from poly(ethylene oxide)-poly(dl-lactic-co-glycolic acid) nanoparticles,” J. Control. Release, Sep. 12, 2006, 114(3):317-324. [cited by applicant]
Bhagav et al., “Sustained release ocular inserts of brimonidine tartrate for better treatment in open-angle glaucoma,” Drug Deliv. Transl. Res., Apr. 2011, 1(2):161-174. [cited by applicant]
Fedorchak et al., “Long Term Glaucoma Drug Delivery Using a Topically Retained Gel/Microsphere Eye Drop,” Sci. Rep., Aug. 2017, 7:8639. [cited by applicant]
U.S. Appl. No. 17/577,816, filed Jan. 18, 2022, Morgan V. Fedorchak, Published as U.S. Publication No. 2022/0202705. [cited by applicant]
U.S. Appl. No. 17/580,988, filed Jan. 21, 2022, Morgan V. Fedorchak, Published as U.S. Publication No. 2022/0211632. [cited by applicant]
Maren et al., “Ocular pharmacology of methazolamide analogs: distribution in the eye and effects on pressure after topical application,” J. Pharmacol. Exp. Ther., Apr. 1987, 241(1):56-63. [cited by applicant]
Park et al., “An anti-angiogenic reverse thermal gel as a drug-delivery system for age-related wet macular degeneration,” Macromol. Biosci., Apr. 2013, 13(4):464-469. [cited by applicant]
U.S. Appl. No. 14/772,758, filed Sep. 3, 2015, Steven R. Little, Published as U.S. Patent Publication No. 2015/0374633. [cited by applicant]
U.S. Appl. No. 16/087,470, filed Sep. 21, 2018, Morgan Virginia Fedorchak, Published as U.S. Patent Publication No. 2019/0099365. [cited by applicant]