Purchase this article with an account.
R. Pijls, L. P. Cruysberg, J. H. L. Hanssen, G. W. Daube, R. M. M. A. Nuijts, L. H. Koole; In vivo Release of Pradofloxacin From a New Ocular Insert for Controlled Drug Delivery. Invest. Ophthalmol. Vis. Sci. 2007;48(13):5786.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Development of a new ocular insert for sustained drug delivery into the tear fluid to increase the bioavailability of drugs and to improve the patient compliance.
The insert exposes a drug-loaded biocompatible hydrogel at its surface. The hydrogel is an adherent coating on a thin coiled metallic wire. The coil is a smooth, flexible structure, which easily adapts to the shape of the inferior conjunctival fornix. Both ends are closed with round caps to avoid any sharp edges. The coating contains the antibiotic pradofloxacin (135 µg, Bayer HealthCare AG, Germany). The lumen of the coil was used as an additional drug reservoir: it contains a polymer rod, consisting of 2-hydroxyethyl methacrylate (HEMA) mixed with 5 w% pradofloxacin (100µg).The insert was tested on two levels: (i) In vitro: simulated tear fluid was pumped along the device and fractions were collected. The drug concentration was measured using a zone of inhibition assay. (ii) In vivo: Beagle dogs received an insert in the conjunctival fornix for 72h (n=8) and aliquots of tear fluid were collected at different time-points. Again, the drug concentration was measured using the bioassay.
The in vitro experiments showed that the lumen of the coil could be filled to increase the capacity. Pradofloxacin was released for 30h. Animal experiments showed that the insert is well tolerated in the canine eye for 72h at least. The concentration of pradofloxacin in the tear fluid stayed above the MIC-value (0.03 µg/mL) during the whole experiment (see Figure).
The insert is well tolerated in the canine eye for 72h at least. Insertion and removal are easily performed with a pair of tweezers. In the animal model, the concentration of the antibiotic remained > MIC-value for 72h. These data hold promise with respect to potential clinical applications (e.g. sustained delivery of antibiotics).
This PDF is available to Subscribers Only