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Updated: Aug 4, 2026
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Use of Rabbit Eyes in Pharmacokinetic Studies of Intraocular Drugs
Published on: July 23, 2016
Intravitreal delivery of ciprofloxacin
D P Hainsworth1, J D Conklin, J R Bierly
1Duke Eye Center, Durham, North Carolina, USA.
Summary
Sustained-release intravitreal devices effectively delivered ciprofloxacin for potential endophthalmitis therapy. This method maintained therapeutic drug levels in the vitreous for four weeks, outperforming subconjunctival injections.
Area of Science:
- Ophthalmology
- Pharmacology
- Biomaterials
Background:
- Endophthalmitis is a severe intraocular infection requiring effective antibiotic delivery.
- Achieving sustained therapeutic drug concentrations in the vitreous humor is challenging with conventional methods.
Purpose of the Study:
- To evaluate bioerodible intravitreal sustained-release devices for ciprofloxacin delivery.
- To compare the efficacy of intravitreal devices versus subconjunctival injections for treating endophthalmitis.
Main Methods:
- In vitro evaluation of two ciprofloxacin-loaded bioerodible intravitreal devices.
- In vivo study in rabbits comparing the most promising device with subconjunctival ciprofloxacin injections.
- Measurement of ciprofloxacin concentrations in aqueous and vitreous humor.
- Clinical examination and electroretinogram to assess retinal safety.
Main Results:
- Subconjunctival injections failed to achieve therapeutic ciprofloxacin levels in the eye.
- Intravitreal devices consistently maintained ciprofloxacin levels above 1 µg/ml in the vitreous for up to four weeks.
- No retinal toxicity was observed with the intravitreal devices.
Conclusions:
- Intravitreal sustained-release ciprofloxacin devices can achieve and maintain therapeutic concentrations in the vitreous.
- This delivery method is well-tolerated and shows promise as a viable treatment for endophthalmitis.
- Further studies in endophthalmitis models are warranted to confirm efficacy.
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