Soft Contact Lenses Capable of Sustained Delivery of Timolol

Alvarez‐Lorenzo, Carmen; Hiratani, Haruyiki; Gómez-Amoza, J.L.; Martínez‐Pacheco, Ramón; Souto, C.

doi:10.1002/jps.10209

Cited by 204 publications

(138 citation statements)

References 35 publications

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“…16 Modulating the composition of the polymer through molecular imprinting allows greater control of uptake and release of timolol 17,18 and the addition of methacrylic acid further increased the amount of drug that can be taken up by the polymer. 19 These synthetic chemistry approaches do not address the issues concerning manufacturing a sterile product containing a drug and vision correction.…”

mentioning

confidence: 99%

A medical device/drug delivery system for treatment of glaucoma

Schultz

Poling²,

Mint

2009

Clinical and Experimental Optometry

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Background:The aim of this study was to investigate the uptake and release kinetics of two common glaucoma drugs delivered onto hydrogel contact lenses using analytical chemistry and to evaluate this device's ability to control intraocular pressure in a limited number of volunteers. Methods: Contact lenses were incubated in a source solution containing timolol maleate or brimonidine tartrate to determine uptake kinetics. The lenses were then immersed in fresh saline to determine release kinetics. Analysis was performed by high-pressure liquid chromatography (HPLC). HPLC column retention times were determined for drugs released from the lens individually and under co-elution conditions. To evaluate clinical feasibility and toxicity, three volunteers (patients being treated for glaucoma) were provided with contact lenses that had been passively impregnated with either drug. After a three-week wash-out period, the volunteers were instructed to wear the lenses for 30 minutes per day for two weeks. Results: HPLC analysis showed that maximum uptake and release of both drugs had occurred by approximately 60 minutes, with the slopes tending to flatten after this point. The retention time on the HPLC column was 8.08 minutes for timolol maleate and 2.16 minutes for brimonidine tartrate after incubation for one hour, with no changes after seven hours. Patient data showed that use of the lenses maintained IOP at levels equivalent to those obtained with previous treatment. No ocular toxicity was observed. Conclusion: Drugs commonly used for glaucoma treatment can be passively transferred to a hydrogel contact lens and then eluted from the polymer. Data obtained from a limited number of patients suggest that this contact lens/drug delivery system may be a feasible means of controlling IOP.

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mentioning

confidence: 99%

A medical device/drug delivery system for treatment of glaucoma

Schultz

Poling²,

Mint

2009

Clinical and Experimental Optometry

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“…It was observed that timolol release was a Case II diffusion with n value close to 1 (n = 0.96; r 2 = 0.98). In the words of Alvarez-Lorenzo et al [21] the release profile of timolol from crosslinked hydroxyethyl methacrylate (HEMA) hydrogels was found to be slow with a n value characteristic of a non-Fickian, anomalous transport. These authors ascribed this finding to a possible increase in hydrogen bonds with the hydroxyl and/or amino groups of timolol.…”

Section: Release Profiles Of Drugsmentioning

confidence: 99%

“…These discs were vacuum dried at room temperature and used for the following study. Drug loading was performed by a soaking procedure, as described elsewhere [20,21]. In short, the samples were immersed either in 5 mL of timolol maleate or sodium flurbiprofen aqueous solutions (0.5 mg/mL) for 3 days at 37 • C. The equilibrium drugs concentrations in the outer solutions were measured by UV-VIS spectrophotometry at their maximum absorvance: 294 nm for timolol and 247 nm for flurbiprofen, using a UV-VIS spectrophotometer (model V550, Jasco).…”

Section: Drug Loading Into St-iema-uv Membranementioning

confidence: 99%

Photocrosslinkable starch-based polymers for ophthalmologic drug delivery

Vieira

Ferreira

Coelho

et al. 2008

International Journal of Biological Macromolecules

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a b s t r a c tThis study focused on the development and characterization of a starch-based polymer with urethane linkages to be used as a controlled drug delivery system for biomedical applications. Starch was modified with 2-isocyanatoethyl methacrylate in order to obtain a polymer containing carbon-carbon double bonds in its structure. This modified starch was then used to produce films by UV irradiation using Irgacure ® 2959 (CIBA) as the photoinitiator. The modified polymer was characterized by attenuated total reflectanceFourier transform infrared (ATR-FTIR) spectroscopy. The swelling capacity, in artificial lachrymal fluid (performed both at room temperature and physiological temperature), and water contact angles measurements were determined. The in vitro biodegradation in artificial lachrymal fluid supplemented with lysozyme was also studied. Scanning electronic microscopy (SEM) was used to characterize the morphology of the materials immediately after synthesis and after biodegradation. Timolol maleate and sodium flurbiprofen were immobilized by adsorption and their in vitro release profiles were followed spectroscopically.

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“…Over the years, experts were perfecting the design and technology of lenses production that resulted in increase of their operational parameters and significantly improved their characteristics for consumers 9,10 . The development of soft lenses gave a powerful impetus to the contact lenses industry.…”

Section: Introductionmentioning

confidence: 99%

A Review on Research of Range and Main Commodity Characteristics of Soft Contact Lenses

Svitlana¹,

Inna²,

Ganna³

et al. 2017

Int. Res. J. Pharm.

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Contact lenses are the most convenient and common means of vision correction worldwide. Soft contact lenses in the world are used by a vast majority of contact vision correction enthusiasts (about 90 % of patients) because the lenses are easy-to-use at the very first application and require almost no adaptation, they have high flexibility, small thickness, and as a result the users feel they have a high comfort level immediately after wearing and also the soft lenses are suitable for correction of all major refractive errors of the eye. The analysis of the range and basic commodity characteristics of soft contact lenses, which are present in the pharmaceutical market of Ukraine has been performed. On the basis of Ukrainian market analysis it has been found that dominant positions of soft contact lenses market have: South Korea, Indonesia, joint v entures of EU countries (UK, Italy, Spain), the US and Singapore, and Australia.

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Soft Contact Lenses Capable of Sustained Delivery of Timolol

Cited by 204 publications

References 35 publications

A medical device/drug delivery system for treatment of glaucoma

A medical device/drug delivery system for treatment of glaucoma

Photocrosslinkable starch-based polymers for ophthalmologic drug delivery

A Review on Research of Range and Main Commodity Characteristics of Soft Contact Lenses

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