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Zhi-yong Qian - One of the best experts on this subject based on the ideXlab platform.
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Toxicity evaluation of biodegradable and thermosensitive PEG‐PCL‐PEG hydrogel as a potential in situ sustained Ophthalmic Drug Delivery system
Journal of Biomedical Materials Research Part B, 2020Co-Authors: Chang Yang Gong, Zhi-yong QianAbstract:In this work, a biodegradable poly(ethylene glycol)-poly(e-caprolactone)-poly (ethylene glycol) (PEG-PCL-PEG, PECE) triblock copolymer was successfully synthesized, which was flowing sol at low temperature and turned to nonflowing gel at body temperature. The toxicity evaluation of PECE hydrogel as a potential in situ sustained opthalmic Drug Delivery system was performed, including the biodegradability of PECE hydrogel in the eye, its effect on cultured human lens epithelia, intraocular pressure, and ocular tissues. The results indicated that the prepared PECE hydrogel was biocompatible and biodegradable despite of temporary elevated intraocular pressure and slight corneal endothelial damage at specific concentration. Therefore, PECE hydrogel may be a safe candidate for sustained Ophthalmic Drug Delivery system. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2010
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Toxicity evaluation of biodegradable and thermosensitive PEG-PCL-PEG hydrogel as a potential in situ sustained Ophthalmic Drug Delivery system
Journal of Biomedical Materials Research - Part B Applied Biomaterials, 2010Co-Authors: Hong Bo Yin, Xu Yang Liu, Chang Yang Gong, Yu Quan Wei, Shuai Shi, Zhi-yong QianAbstract:In this work, a biodegradable poly(ethylene glycol)-poly(epsilon-caprolactone)-poly (ethylene glycol) (PEG-PCL-PEG, PECE) triblock copolymer was successfully synthesized, which was flowing sol at low temperature and turned to nonflowing gel at body temperature. The toxicity evaluation of PECE hydrogel as a potential in situ sustained opthalmic Drug Delivery system was performed, including the biodegradability of PECE hydrogel in the eye, its effect on cultured human lens epithelia, intraocular pressure, and ocular tissues. The results indicated that the prepared PECE hydrogel was biocompatible and biodegradable despite of temporary elevated intraocular pressure and slight corneal endothelial damage at specific concentration. Therefore, PECE hydrogel may be a safe candidate for sustained Ophthalmic Drug Delivery system.
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toxicity evaluation of biodegradable and thermosensitive peg pcl peg hydrogel as a potential in situ sustained Ophthalmic Drug Delivery system
Journal of Biomedical Materials Research Part B, 2010Co-Authors: Chang Yang Gong, Zhi-yong QianAbstract:In this work, a biodegradable poly(ethylene glycol)-poly(e-caprolactone)-poly (ethylene glycol) (PEG-PCL-PEG, PECE) triblock copolymer was successfully synthesized, which was flowing sol at low temperature and turned to nonflowing gel at body temperature. The toxicity evaluation of PECE hydrogel as a potential in situ sustained opthalmic Drug Delivery system was performed, including the biodegradability of PECE hydrogel in the eye, its effect on cultured human lens epithelia, intraocular pressure, and ocular tissues. The results indicated that the prepared PECE hydrogel was biocompatible and biodegradable despite of temporary elevated intraocular pressure and slight corneal endothelial damage at specific concentration. Therefore, PECE hydrogel may be a safe candidate for sustained Ophthalmic Drug Delivery system. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2010
Chang Yang Gong - One of the best experts on this subject based on the ideXlab platform.
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Toxicity evaluation of biodegradable and thermosensitive PEG‐PCL‐PEG hydrogel as a potential in situ sustained Ophthalmic Drug Delivery system
Journal of Biomedical Materials Research Part B, 2020Co-Authors: Chang Yang Gong, Zhi-yong QianAbstract:In this work, a biodegradable poly(ethylene glycol)-poly(e-caprolactone)-poly (ethylene glycol) (PEG-PCL-PEG, PECE) triblock copolymer was successfully synthesized, which was flowing sol at low temperature and turned to nonflowing gel at body temperature. The toxicity evaluation of PECE hydrogel as a potential in situ sustained opthalmic Drug Delivery system was performed, including the biodegradability of PECE hydrogel in the eye, its effect on cultured human lens epithelia, intraocular pressure, and ocular tissues. The results indicated that the prepared PECE hydrogel was biocompatible and biodegradable despite of temporary elevated intraocular pressure and slight corneal endothelial damage at specific concentration. Therefore, PECE hydrogel may be a safe candidate for sustained Ophthalmic Drug Delivery system. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2010
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Toxicity evaluation of biodegradable and thermosensitive PEG-PCL-PEG hydrogel as a potential in situ sustained Ophthalmic Drug Delivery system
Journal of Biomedical Materials Research - Part B Applied Biomaterials, 2010Co-Authors: Hong Bo Yin, Xu Yang Liu, Chang Yang Gong, Yu Quan Wei, Shuai Shi, Zhi-yong QianAbstract:In this work, a biodegradable poly(ethylene glycol)-poly(epsilon-caprolactone)-poly (ethylene glycol) (PEG-PCL-PEG, PECE) triblock copolymer was successfully synthesized, which was flowing sol at low temperature and turned to nonflowing gel at body temperature. The toxicity evaluation of PECE hydrogel as a potential in situ sustained opthalmic Drug Delivery system was performed, including the biodegradability of PECE hydrogel in the eye, its effect on cultured human lens epithelia, intraocular pressure, and ocular tissues. The results indicated that the prepared PECE hydrogel was biocompatible and biodegradable despite of temporary elevated intraocular pressure and slight corneal endothelial damage at specific concentration. Therefore, PECE hydrogel may be a safe candidate for sustained Ophthalmic Drug Delivery system.
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toxicity evaluation of biodegradable and thermosensitive peg pcl peg hydrogel as a potential in situ sustained Ophthalmic Drug Delivery system
Journal of Biomedical Materials Research Part B, 2010Co-Authors: Chang Yang Gong, Zhi-yong QianAbstract:In this work, a biodegradable poly(ethylene glycol)-poly(e-caprolactone)-poly (ethylene glycol) (PEG-PCL-PEG, PECE) triblock copolymer was successfully synthesized, which was flowing sol at low temperature and turned to nonflowing gel at body temperature. The toxicity evaluation of PECE hydrogel as a potential in situ sustained opthalmic Drug Delivery system was performed, including the biodegradability of PECE hydrogel in the eye, its effect on cultured human lens epithelia, intraocular pressure, and ocular tissues. The results indicated that the prepared PECE hydrogel was biocompatible and biodegradable despite of temporary elevated intraocular pressure and slight corneal endothelial damage at specific concentration. Therefore, PECE hydrogel may be a safe candidate for sustained Ophthalmic Drug Delivery system. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2010
Anuj Chauhan - One of the best experts on this subject based on the ideXlab platform.
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temperature sensitive contact lenses for triggered Ophthalmic Drug Delivery
Biomaterials, 2012Co-Authors: Hyun Jung Jung, Anuj ChauhanAbstract:Abstract Ophthalmic Drug Delivery through eye drops is inefficient because of low corneal bioavailability and short residence time in tears. Contact lenses are ideally suited for extended and targeted Drug Delivery to cornea, but commercial contact lenses release Ophthalmic Drugs for only 1–2 h. This study focuses on dispersing timolol encapsulating highly crosslinked nanoparticles in contact lenses to increase the duration of Drug release from 1 to 2 h to about 2–4 weeks. The highly crosslinked particles were prepared from monomers with multivinyl functionalities such as EGDMA (ethylene glycol dimethacrylate) and PGT (propoxylated glyceryl triacylate). The nanoparticles were about 3.5 nm in size and encapsulated 48–66% of the Drug depending on the composition. Drug release studies in a diffusion cell showed that the particles released the Drug for a period of about 4 weeks. The Drug loaded particles were dispersed in hydroxy methyl methacrylate (HEMA) gels, which are common contact lens materials. The particle loaded gels release timolol in phosphate buffered saline (PBS) for 2–4 weeks at therapeutic dose, which is promising for extended Drug release applications. The proposed mechanism of Drug transport is hydrolysis of ester bonds that link timolol to the particle matrix which form during the particle formation process. The Drug release profiles can be described by a first order reaction model with a temperature dependent rate constant. The rate constant of ester hydrolysis was significantly smaller than that in previous studies on timolol esters possibly due to steric effects and the low water content of the highly crosslinked hydrophobic particles. The results of this study provide evidences that contact lenses loaded with nanoparticles could be very useful for extended Delivery of Ophthalmic Drugs.
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modeling Ophthalmic Drug Delivery by soaked contact lenses
Industrial & Engineering Chemistry Research, 2006Co-Authors: Chichung Li, Anuj ChauhanAbstract:Approximately 90% of all Ophthalmic Drug formulations are now applied as eye drops. While eye drops are convenient and well-accepted by patients, ∼95% of the Drug contained in the drops is lost due to absorption through the conjunctiva or through the tear drainage. Ophthalmic Drug Delivery via contact lenses is more effective because it increases the residence time of the Drug in the eye and leads to a larger fractional intake of Drug by the cornea. In this paper, we model the Drug release from the contact lens into the pre- and postlens tear films and the subsequent uptake by the cornea. The motion of the contact lens, which is driven by the eyelid motion during a blink, enhances the mass transfer in the postlens tear film (POLTF). We use regular perturbation methods to obtain the Taylor dispersion coefficient for mass transfer in the POLTF. The diffusion of Drug in the gel is assumed to obey Fick's law, and the diffusion in the gel and the mass transfer in the POLTF are combined to yield an integro-diff...
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dispersion of microemulsion drops in hema hydrogel a potential Ophthalmic Drug Delivery vehicle
International Journal of Pharmaceutics, 2005Co-Authors: Derya Gulsen, Anuj ChauhanAbstract:Approximately 90% of all Ophthalmic Drug formulations are now applied as eye-drops. While eye-drops are convenient and well accepted by patients, about 95% of the Drug contained in the drops is lost due to absorption through the conjunctiva or through the tear drainage. A major fraction of the Drug eventually enters the blood stream and may cause side effects. The Drug loss and the side effects can be minimized by using disposable soft contact lenses for Ophthalmic Drug Delivery. The essential idea is to encapsulate the Ophthalmic Drug formulations in nanoparticles, and disperse these Drug-laden particles in the lens material. Upon insertion into the eye, the lens will slowly release the Drug into the pre lens (the film between the air and the lens) and the post-lens (the film between the cornea and the lens) tear films, and thus provide Drug Delivery for extended periods of time. This paper focuses on dispersing stabilized microemulsion drops in poly-2-hydroxyethyl methacrylate (p-HEMA) hydrogels. The results of this study show that the p-HEMA gels loaded with a microemulsion that is stabilized with a silica shell are transparent and that these gels release Drugs for a period of over 8 days. Contact lenses made of microemulsion-laden gels are expected to deliver Drugs at therapeutic levels for a few days. The Delivery rates can be tailored by controlling the particle and the Drug loading. It may be possible to use this system for both therapeutic Drug Delivery to eyes and the provision of lubricants to alleviate eye problems prevalent in extended lens wear.
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Ophthalmic Drug Delivery through contact lenses
Investigative Ophthalmology & Visual Science, 2004Co-Authors: Derya Gulsen, Anuj ChauhanAbstract:PURPOSE. Currently available Ophthalmic Drug Delivery systems are inefficient and may lead to side effects. To increase efficiency and reduce side effects, the authors propose disposable particle-laden soft contact lenses for Ophthalmic Drug Delivery. METHODS. The essential idea is to encapsulate the Ophthalmic Drug formulations in nanoparticles and to disperse these Drug-laden particles in the lens material, such as poly-2-hydroxyethyl methacrylate (p-HEMA) hydrogels. The Drug-laden p-HEMA hydrogels were synthesized by free radical solution polymerization of the monomers in presence of nanoparticles. The particle-laden hydrogels were characterized by light-transmission and electron microscopy studies. Release profiles of lidocaine, a model hydrophobic Drug, were measured by UV-Vis spectrophotometry. RESULTS. Microemulsions of hexadecane in water stabilized with a silica shell around the particles produced transparent hydrogels. Contact lenses made with particle-laden hydrogels released therapeutic levels of Drug for a few days. CONCLUSIONS. Particle-laden hydrogels are promising candidates for Ophthalmic Drug Delivery. They are transparent and can release Drugs for extended periods. The Drug Delivery rates can be controlled by varying the loading of nanoparticles in the gel.
Chao Wang - One of the best experts on this subject based on the ideXlab platform.
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pluronic f127 g poly acrylic acid copolymers as in situ gelling vehicle for Ophthalmic Drug Delivery system
International Journal of Pharmaceutics, 2008Co-Authors: Hui Xu, Chao WangAbstract:To prolong the precorneal resident time and improve ocular bioavailability of the Drug, Pluronic F127-g-poly(acrylic acid) copolymers were studied as in situ gelling vehicle for Ophthalmic Drug Delivery system. The rheological properties and in vitro Drug release of Pluronic-g-PAA copolymer gels were investigated. The rheogram and in vitro Drug release studies indicated that the Drug release rates decreased as acrylic acid/Pluronic molar ratio and copolymer solution concentration increased. But the Drug concentration had no obvious effect on Drug release. The release rates of the Drug from such copolymer gels were mainly dependent on the gel dissolution. In vivo resident experiments showed the Drug resident time and the total resident amount in rabbit's conjunctiveal sac increased by 5.0 and 2.6 folds for in situ gel, compared with eye drops. The decreased loss angle at body temperature and prolonged precorneal resident time also indicated that the copolymer gels had bioadhesive properties. These in vivo experimental results, along with the rheological properties and in vitro Drug release studies, demonstrated that in situ gels containing Pluronic-g-PAA copolymer may significantly prolong the Drug resident time and thus improve bioavailability. Pluronic-g-PAA copolymer can be a promising in situ gelling vehicle for Ophthalmic Drug Delivery system.
Hui Xu - One of the best experts on this subject based on the ideXlab platform.
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Temperature-Responsive, Pluronic-g-poly(acrylic acid) Copolymers In Situ Gels for Ophthalmic Drug Delivery: Rheology, In Vitro Drug Release, and In Vivo Resident Property
Drug Development and Industrial Pharmacy, 2008Co-Authors: Wen-di Ma, Hui XuAbstract:To prolong the precorneal resident time and improve ocular bioavailability of the Drug, Pluronic-g-poly(acrylic acid) copolymers were studied as a temperature-responsive in situ gelling vehicle for an Ophthalmic Drug Delivery system. The rheological properties and in vitro Drug release of Pluronic-g-PAA copolymer gels, as well as the in vivo resident properties of such in situ gel Ophthalmic formulations, were investigated. The rheogram and in vitro Drug release studies indicated that the Drug release rates decreased as acrylic acid/Pluronic molar ratio and copolymer solution concentration increased. It was also shown that the Drug concentration had no obvious effect on Drug release. The release rates of Drug from such copolymer gels were mainly dependent on the gel dissolution. In vivo resident experiments showed the Drug resident time and the total resident amount increased by 4-fold and 1.2-fold for in situ gel compared with eye drops. These in vivo experimental results, along with the rheological properties and in vitro Drug release studies, demonstrated that in situ gels containing Pluronic-g-PAA copolymer may significantly prolong the Drug resident time and thus improve bioavailability. The results showed that the Pluronic-g-PAA copolymer can be a promising in situ gelling vehicle for Ophthalmic Drug Delivery.
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pluronic f127 g poly acrylic acid copolymers as in situ gelling vehicle for Ophthalmic Drug Delivery system
International Journal of Pharmaceutics, 2008Co-Authors: Hui Xu, Chao WangAbstract:To prolong the precorneal resident time and improve ocular bioavailability of the Drug, Pluronic F127-g-poly(acrylic acid) copolymers were studied as in situ gelling vehicle for Ophthalmic Drug Delivery system. The rheological properties and in vitro Drug release of Pluronic-g-PAA copolymer gels were investigated. The rheogram and in vitro Drug release studies indicated that the Drug release rates decreased as acrylic acid/Pluronic molar ratio and copolymer solution concentration increased. But the Drug concentration had no obvious effect on Drug release. The release rates of the Drug from such copolymer gels were mainly dependent on the gel dissolution. In vivo resident experiments showed the Drug resident time and the total resident amount in rabbit's conjunctiveal sac increased by 5.0 and 2.6 folds for in situ gel, compared with eye drops. The decreased loss angle at body temperature and prolonged precorneal resident time also indicated that the copolymer gels had bioadhesive properties. These in vivo experimental results, along with the rheological properties and in vitro Drug release studies, demonstrated that in situ gels containing Pluronic-g-PAA copolymer may significantly prolong the Drug resident time and thus improve bioavailability. Pluronic-g-PAA copolymer can be a promising in situ gelling vehicle for Ophthalmic Drug Delivery system.