Absorption of Brimonidine 0.1% and 0.15% Ophthalmic Solutions in the Aqueous Humor of Cataract Patients

Cantor, Louis B.; WuDunn, Darrell; Catoira-Boyle, Yara; Yung, Chi Wah

doi:10.1097/ijg.0b013e318162257f

Cited by 20 publications

(8 citation statements)

References 20 publications

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“…Neither BMD nor TIM contains EDTA. In addition, the bioavailability of brimonidine and timolol in the aqueous humor following ophthalmic administration is enhanced by increasing the solution pH, in accordance with the pH partition hypothesis [23][24][25]. For a fixed-combination drug, these differences in formulation raised a concern about whether corneal drug penetrations of brimonidine and timolol were changed or not.…”

Section: Discussionmentioning

confidence: 76%

Ocular and Systemic Pharmacokinetics of Brimonidine and Timolol After Topical Administration in Rabbits: Comparison Between Fixed-Combination and Single Drugs

et al. 2020

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Introduction: This study was aimed to compare ocular tissue distribution and systemic exposure of brimonidine and timolol after single topical administration to rabbits of fixed-combination ophthalmic solution of 0.1% brimonidine tartrate and 0.5% timolol and single drugs (0.1% brimonidine tartrate ophthalmic solution or 0.5% timolol ophthalmic solution) or concomitant administration of single drugs. Methods: Rabbits were treated with a single topical administration of each ophthalmic solution or concomitant administration of single drugs. For concomitant administration, 0.1% brimonidine tartrate was administered after 0.5% timolol instillation successively within 10 s (without interval) or with 5-min intervals. Brimonidine and timolol concentrations in the aqueous humor, retina/choroid, vitreous body, and plasma were determined with liquid chromatography-tandem mass spectrometry.

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Section: Discussionmentioning

confidence: 76%

Ocular and Systemic Pharmacokinetics of Brimonidine and Timolol After Topical Administration in Rabbits: Comparison Between Fixed-Combination and Single Drugs

et al. 2020

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“…8 To confirm whether the concentration of brimonidine in the vitreous is enough to exhibit neuroprotection in the retina, quantitative measurement of the drug in ocular media has been carried out after the topical administration of brimonidine tartrate 0.2% and 0.15%. 9,10 Most of the brimonidine tartrate-administered eyes showed the concentration of more than 2 nM in the vitreous, which is known to activate neuroprotective a-2 receptors in animal retina. 11 However, the concentrations of the human aqueous humor or vitreous after the topical administration of ophthalmic solution 0.1% have not been evaluated.…”

Section: Introductionmentioning

confidence: 99%

Vitreous and Aqueous Concentrations of Brimonidine Following Topical Application of Brimonidine Tartrate 0.1% Ophthalmic Solution in Humans

Takamura

Tomomatsu

Matsumura

et al. 2015

Journal of Ocular Pharmacology and Therapeutics

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“…Brimonidine tartrate decreases the IOP by reducing the production of aqueous humor and increasing its outflow via the uveoscleral pathway [1]. It has been reported that the bioavailability of brimonidine in the aqueous humor following ophthalmic administration is enhanced by increasing the solution pH, in accordance with the pH partition hypothesis [2–4]. Brimonidine is a base (p K a = 7.78), and this change in bioavailability is assumed to be caused by the increase in non-ionized molecules, which have a higher membrane permeability than ionized molecules in a more alkaline pH.…”

Section: Introductionmentioning

confidence: 86%

Effect of Solution pH on Distribution of Ophthalmically Administered Brimonidine in Posterior Ocular Tissues in Pigmented Rabbits

et al. 2019

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Introduction Brimonidine bioavailability in the aqueous humor depends on the solution pH following topical administration. The purpose of this study was to investigate the effect of solution pH on brimonidine distribution in the posterior ocular tissues in pigmented rabbits. Methods The anterior retina/choroid, posterior retina/choroid, and vitreous body of pigmented rabbits were collected 0.67, 1.5, 3, 6, 12, 24, 168, and 360 h after the administration of a single topical dose of 0.2% brimonidine tartrate ophthalmic solution, pH 6.4 (Alphagan ® ; Allergan Inc., Irvine, CA, USA). Brimonidine concentrations in these tissues were quantified using liquid chromatography/tandem mass spectrometry. Pharmacokinetic parameters were determined using noncompartmental analysis, and the results were compared with tissues from eyes administered 0.1% brimonidine tartrate ophthalmic solution, pH 7.3 (Aiphagan ® ; Senju Pharmaceutical Co., Ltd., Osaka, Japan) in our previous study conducted using the same procedure. Results Topically applied brimonidine was distributed rapidly into the posterior tissues of the eye after a single ophthalmic administration of the 0.2% ophthalmic solution. The areas under the curve from time 0 to 360 h following dosing with the 0.2% ophthalmic solution were 500,000, 14,300, and 28.7 ng h/g in the anterior and posterior retina/choroid, and vitreous body, respectively. Conclusion The differences in the areas under the curve between two ophthalmic solutions were less than the difference in drug concentrations between these two products in any tissues. This finding indicates that the change in the solution pH from 6.4 to 7.3 increases brimonidine bioavailability into the posterior ocular tissues similarly as into the aqueous humor. Funding Senju Pharmaceutical Co., Ltd.

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Absorption of Brimonidine 0.1% and 0.15% Ophthalmic Solutions in the Aqueous Humor of Cataract Patients

Cited by 20 publications

References 20 publications

Ocular and Systemic Pharmacokinetics of Brimonidine and Timolol After Topical Administration in Rabbits: Comparison Between Fixed-Combination and Single Drugs

Ocular and Systemic Pharmacokinetics of Brimonidine and Timolol After Topical Administration in Rabbits: Comparison Between Fixed-Combination and Single Drugs

Vitreous and Aqueous Concentrations of Brimonidine Following Topical Application of Brimonidine Tartrate 0.1% Ophthalmic Solution in Humans

Effect of Solution pH on Distribution of Ophthalmically Administered Brimonidine in Posterior Ocular Tissues in Pigmented Rabbits

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