Release of Moxifloxacin from Contact Lenses Using an In Vitro Eye Model: Impact of Artificial Tear Fluid Composition and Mechanical Rubbing

Abstract

PurposeThe aim of this study was to evaluate and compare the release of moxifloxacin from a variety of daily disposable (DD) contact lenses (CLs) under various conditions using a novel in vitro eye model.MethodsFour commercially available DD conventional hydrogel (CH) CLs (nelfilcon A, omafilcon A, etafilcon A, and ocufilcon B) and three silicone hydrogel (SH) CLs (somofilcon A, narafilcon A, and delefilcon A) were evaluated. These lenses were incubated in moxifloxacin for 24 hours. The release of the drug was measured using a novel in vitro model in three experimental conditions: (1) phosphate buffered saline (PBS); (2) artificial tear solution (ATS) containing a variety of proteins and lipids; and (3) ATS with mechanical rubbing produced by the device.ResultsOverall, CH CLs had a higher drug release than SH CLs (P < 0.05) under all conditions. Typically, a higher drug release was observed in PBS than ATS (P < 0.05). For CH, drug release was found to be higher in ATS with rubbing than PBS or ATS (P < 0.05). For most lens types, ATS with rubbing produced higher drug release than ATS alone (P < 0.05). Generally, the release kinetics for all conditions were sustained over the 24-hour testing period, and no burst release was observed (P < 0.05).ConclusionsMoxifloxacin release from a CL into ATS is lower when compared to release into PBS. When mechanical rubbing is introduced, the amount of drugs released is increased.Translational RelevanceResults suggest that sophisticated in vitro models are necessary to adequately model on-eye drug release from CL materials.

A Rapid Extraction Method to Quantify Drug Uptake in Contact Lenses

“…These results have been observed in previous studies with moxifloxacin. 38 , 40 There were no significant differences in uptake between CH CLs and SH CLs observed for natamycin and ketotifen fumarate ( P > 0.05), which are also similar to previously published results. 6 , 8 …”

“…These drugs have been used to study a range of potential ocular therapies using CL drug delivery. 3 , 6 , 8 , 16 , 38 , 40 A simple extraction approach was developed using methanol as the extraction solvent. The method consists of incubating CLs in methanol for 2 hours to remove the bound drugs, and this was repeated for a total of three cycles.…”

Determination of the release of PEG and HPMC from nelfilcon A daily disposable contact lenses using a novel in vitro eye model

“…Under these circumstances, a flow system, such as the OcuFlow system utilised in this study, may be a better model to predict actual conditions found in the eye during normal wear. The release of components from CLs is much slower under a flow system, and is affected by tear volume and flow rate [22,28,32,38]. However, for very hydrophilic compounds such as PEG and HPMC, the release may still be rapid.…”

“…In addition, in this study Milli-Q water was used to measure the release rates of the compounds instead of an artificial tear fluid. In a previous study evaluating the release of a hydrophilic molecule, moxifloxacin, from CL using the OcuFlow, it was found that the release of the compound was faster in PBS than artificial tear fluid [32]. Similarly, since PEG and HPMC are also hydrophilic, the release of these compounds may also be faster in Milli-Q water than in human tear fluid.…”

“…However, this model does not simulate appropriate tear volume and natural tear flow [20,21], air exposure, and mechanical rubbing, which are factors which can significantly impact release kinetics. We have recently developed an in vitro model (OcuFlow) that allows lenses to be examined on a corneal-shaped profile that exposes the lens to a blinkactuator that mimics the action of the lid blinking, mimics the inter-blink period, and also flows an artificial tear fluid over the lens at physiologically relevant rates of replenishment and quantity, and permits any elute from the lens to be captured and subsequently analysed [22,[28][29][30][31][32].…”