Abstract
Purpose :
Topical ocular antibiotics are often prescribed for antimicrobial prophylaxis following ophthalmic surgery or for the treatment of bacterial conjunctivitis. Sustained-release delivery of antibiotics may overcome some limitations of topical therapy such as reliance on patient self-dosing. Here we evaluate the pharmacokinetics of besifloxacin delivered from a biodegradable hydrogel intracanalicular insert in a canine model.
Methods :
A hydrogel besifloxacin intracanalicular insert was placed bilaterally into the inferior canaliculus of 20 beagle dogs on day 0. After presence of the insert in the canaliculus was confirmed visually, tear fluid was collected from n=10 eyes with pre-cut 10 mm Schirmer test strips at 0.5, 1, 2, 4, 8 hours, and 1, 3, 7, 10, 14, 21, 28, 35, and 42 days post-insertion. Tear fluid samples were analyzed for besifloxacin by liquid chromatography tandem mass spectrometry.
Results :
Mean besifloxacin levels in tear fluid samples post-insertion are presented in Figure 1. Mean besifloxacin levels in tear fluid samples demonstrated gradual tapering over time and clearance from the tear fluid by 35-42 days. All AUC0-24/MIC90 values were above 100 for 21 days for H. influenzae, S. aureus, S. epidermis, and S. pneumoniae suggesting the insert produced bactericidal levels of besifloxacin for common ocular isolates of conjunctivitis.
Conclusions :
A hydrogel-based intracanalicular insert with besifloxacin produced clinically effective drug levels capable of killing the most common isolates of bacterial conjunctivitis for 21 days. A single dose besifloxacin intracanalicular insert may reduce the need for patients to self-administer antimicrobial therapy.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.