Intravitreal Vancomycin

Pflugfelder, Stephen C.; Hernandez, E.; Fliesler, Steven J.; Alvarez, J Garcia; Pflugfelder, Maureen E.; Forster, Richard K.

doi:10.1001/archopht.1987.01060060117045

Cited by 121 publications

(11 citation statements)

References 23 publications

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“…Although the cause for this difference between the two agents is unclear, the decreased retention time after lensectomy may indicate the addition of an anterior escape route despite preservation of the anterior capsule. Pflugfelder et al 12 found that preservation of the anterior capsule slows the clearance rate of intravitreal agents and more accurately simulates a phakic model in a rabbit. Because the vitreous and the posterior lens capsule are usually preserved during cataract surgery, it seems plausible that the clearance half-life of intravitreal anti-VEGF therapy would not be greatly affected in pseudophakic patients.…”

Section: Discussionmentioning

confidence: 99%

Anatomic and Pharmacokinetic Properties of Intravitreal Bevacizumab and Ranibizumab After Vitrectomy and Lensectomy

Christoforidis

Williams²,

Wang³

et al. 2013

Retina

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Purpose To determine the anatomic characteristics and pharmacokinetic properties of intravitreally placed bevacizumab and ranibizumab after pars plana lensectomy or pars plana vitrectomy and to compare these with nonoperated control eyes in a rabbit model. Methods Three groups of six Dutch-belted rabbits each underwent pars plana vitrectomy, pars plana lensectomy, or served as nonsurgical controls. Twelve days after surgery, 3 rabbits from each group underwent intravitreal injection in one eye with 1.25 mg/0.05 mL I-124–bevacizumab or 0.5 mg/0.05 mL I-124-ranibizumab. Serial imaging with PET/CT were obtained on Days 0, 2, 5, 7, 14, 21, 28, and 35. Measured radioactivity emission in becquerels/milliliter was used to calculate the half-lives for each agent. Results The intravitreally placed radiolabeled agents were contained within the vitreous cavity for the duration of the study. The average clearance half-lives with standard error for bevacizumab and ranibizumab after correction for radioactive decay were, respectively, 4.22 ± 0.07 days and 2.81 ± 0.05 days in unoperated eyes, 2.30 ± 0.09 days (P < 0.0001) and 2.13 ± 0.05 days (P < 0.0001) after vitrectomy, and 2.08 ± 0.07 days (P = 0.0001) and 1.79 ± 0.05 days (P < 0.0001) after lensectomy. Conclusion Intravitreal retention was longer for bevacizumab than ranibizumab within all study groups and was significantly reduced after vitrectomy and lensectomy for both agents. Consideration for more frequent intravitreal anti–vascular endothelial growth factor dosing regimens may be made for patients whose treated eyes have undergone previous vitrectomy or who are aphakic.

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Section: Discussionmentioning

confidence: 99%

Anatomic and Pharmacokinetic Properties of Intravitreal Bevacizumab and Ranibizumab After Vitrectomy and Lensectomy

Christoforidis

Williams²,

Wang³

et al. 2013

Retina

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“…Murphy et al 25 reported that the MIC of vancomycin for gram-positive endophthalmitis causing pathogens is 4 mg/L and in the majority of cases is in the range of 0.5 to 1.0 mg/L. 26,27 The sensitivity of the fluorescent polarization immunoassay (TDx-FLx System Abbott) was 2 lg/mL. The method of determining the concentration of vancomycin assays by fluorescent polarization immunoassay was a modified version of those described by Huerva et al 28 and Alster et al 29 The limit of detection of the vancomycin concentration in the rabbit eyes tear fluid came from the small volume of sample taken in the glass capillaries (2 lL).…”

Section: Pharmacokinetics Of Topically Applied Vancomycin In Rabbit Eyesmentioning

confidence: 42%

Chitosan as an ocular drug delivery vehicle for vancomycin

Khangtragool¹,

Ausayakhun²,

Leesawat³

et al. 2011

J of Applied Polymer Sci

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ABSTRACT:The main objective of this research has been to study the efficiency of chitosan as an ocular drug delivery vehicle for topically applied vancomycin in rabbit eyes. Vancomycin 50 mg/mL was reconstituted in four preparations, namely: in Tears Naturale II TM , in 0.9% w/v aqueous sodium chloride, and in 0.1% and 0.3% w/v chitosan solutions in 1% aqueous L(þ)-lactic acid. Twenty-five microliters of vancomycin (50 mg/mL) were applied into the lower conjunctival eye sac in rabbit eyes. Tear samples were then collected after 0, 30, 60, 90, and 120 min to evaluate the pharmacokinetics of the topically applied vancomycin. Comparison of the results obtained showed that vancomycin 50 mg/mL eye drops in the 0.3% chitosan solution were similar to Tears Naturale II TM in terms of bioavailability. The main conclusion to be drawn from this study is that the 0.3% w/v chitosan solution appears to be a highly promising, cost effective candidate for biomedical use as a vehicle for vancomycin ocular drug delivery.

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“…Although placement of an intraocular lens after lensectomy would better simulate pseudophakia, the rabbit is a challenging animal model for successfully performing this procedure consistently due to severe miosis and an exudative fibrinous response in rabbit eyes. We left the anterior capsule intact in the aphakic eyes to more closely simulate pseudophakia as previously reported by Pflugfelder et al 33 Further studies utilizing an animal model that more closely simulates pseudophakia are warranted to more accurately examine serum levels of intravitreal anti-VEGF agents in pseudophakic patients.…”

Section: Discussionmentioning

confidence: 99%

Serum Levels of Intravitreal Bevacizumab After Vitrectomy, Lensectomy and Non-Surgical Controls

Christoforidis

Xie²,

Jiang³

et al. 2013

Current Eye Research

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Purpose To determine serum level differences of intravitreally-placed bevacizumab after vitrectomy and lensectomy-vitrectomy and to compare these with non-operated eyes in a rabbit model. Methods Five Dutch-belted rabbits underwent pars plana vitrectomy (PPV), 5 rabbits underwent pars plana lensectomy (PPL) and 5 rabbits served as non-surgical controls. Twelve days following the surgical procedures, each operated eye underwent an intravitreal injection consisting of 1.25 mg/0.05 mL bevacizumab. Serum levels from each rabbit were drawn on days 2, 4, 7, 10, 14, 21, 28 and 35 and were measured with ELISA immunoassay. Results The average peak serum concentration (Cmax) was highest for the PPL group (11.33 µg ± 3.48 mL), and was similar between the PPV (5.35 µg ± 2.69 mL) and non-surgical control groups (5.35 µg ± 0.69 mL). The average time to maximal plasma concentration (Tmax) in days was earliest for the PPL group (2.8 ± 0.47), followed by the PPV (5.6 ± 0.84) and non-surgical control groups (6.4 ± 0.71). The PPL group had higher serum levels than the other 2 groups until day 7 that was significant only at day 2 (p<0.0001). After day 4 there were no significant differences or trends between any of the 3 groups. The half-life (T1/2) was fastest for the PPL group (1.41±0.21 days) followed by the PPV (2.80±3.35 days) and non-surgical control groups (6.69±10.4 days). Conclusions Serum bevacizumab levels were initially elevated following lensectomy and vitrectomy compared to non-surgical eyes following intravitreal injection. The half-life of bevacizumab was prolonged in non-surgical eyes presumably due to a slower release from the vitreous cavity.

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Intravitreal Vancomycin

Cited by 121 publications

References 23 publications

Anatomic and Pharmacokinetic Properties of Intravitreal Bevacizumab and Ranibizumab After Vitrectomy and Lensectomy

Anatomic and Pharmacokinetic Properties of Intravitreal Bevacizumab and Ranibizumab After Vitrectomy and Lensectomy

Chitosan as an ocular drug delivery vehicle for vancomycin

Serum Levels of Intravitreal Bevacizumab After Vitrectomy, Lensectomy and Non-Surgical Controls

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