Release of Ciprofloxacin and Moxifloxacin From Daily Disposable Contact Lenses From an In Vitro Eye Model

Bajgrowicz, M., Phan, C.-M., Subbaraman, L. N., & Jones, L. (2015). Release of Ciprofloxacin and Moxifloxacin From Daily Disposable Contact Lenses From an In Vitro Eye Model. Investigative Opthalmology & Visual Science, 56(4), 2234. https://doi.org/10.1167/iovs.15-16379Purpose.: To analyze the release of two fluoroquinolones, ciprofloxacin and moxifloxacin, from conventional hydrogel (CH) and silicone hydrogel (SH) daily disposable contact lenses (CLs), comparing release from a fixed-volume vial and a novel in vitro eye model. Methods.: Four CH CLs (nelfilcon A, omafilcon A, etafilcon A, ocufilcon B) and three SH CLs (somofilcon A, narafilcon A, delefilcon A) were used. The lenses were incubated in drug solutions for 24 hours. After the incubation period, the lenses were placed in two release conditions: (1) a vial containing 4.8 mL PBS for 24 hours and (2) an in vitro eye model with a flow rate at 4.8 mL over 24 hours. Results.: Release in the vial for both drugs was rapid, reaching a plateau between 15 minutes and 2 hours for all lenses. In contrast, under physiological flow conditions, a constant and slow release was observed over 24 hours. The amounts of ciprofloxacin released from the lenses ranged between 49.6 ± 0.7 and 62.8 ± 0.3 μg per lens in the vial, and between 35.0 ± 7.0 and 109.0 ± 5.0 μg per lens in the eye model. Moxifloxacin release ranged from 24.0 ± 4.0 to 226.0 ± 2.0 μg per lens for the vial, and between 13.0 ± 2.0 and 151.0 ± 10.0 μg per lens in the eye model. In both systems and for both drugs, HEMA-based CLs released more drugs than other materials. Conclusions.: The parameters of the release system, in particular the volume and flow rate, have a significant influence on measured release profiles. Under physiological flow, release profiles are significantly slower and constant when compared with release in a vial

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

Phan, C.-M., Bajgrowicz-Cieslak, M., Subbaraman, L. N., & Jones, L. (2016). Release of Moxifloxacin from Contact Lenses Using an In Vitro Eye Model: Impact of Artificial Tear Fluid Composition and Mechanical Rubbing. Translational Vision Science & Technology, 5(6), 3. https://doi.org/10.1167/tvst.5.6.3Purpose: The 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. Methods: Four 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. Results: Overall, 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). Conclusions: Moxifloxacin 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 Relevance: Results suggest that sophisticated in vitro models are necessary to adequately model on-eye drug release from CL materials

Optical glucose sensors based on hexagonally-packed 2.5-dimensional photonic concavities imprinted in phenylboronic acid functionalized hydrogel films

Continuous glucose monitoring aims to achieve accurate control of blood glucose concentration to prevent hypo/hyperglycaemia in diabetic patients. Hydrogel-based systems have emerged as a reusable sensing platform to quantify biomarkers in high-risk patients at clinical and point-of-care settings. The capability to integrate hydrogel-based systems with optical transducers will provide quantitative and colorimetric measurements via spectrophotometric analyses of biomarkers. Here, we created an imprinting method to rapidly produce 2.5D photonic concavities in phenylboronic acid functionalized hydrogel films. Our method exploited diffraction properties of hexagonally-packed 2.5D photonic microscale concavities having a lattice spacing of 3.3 μm. Illumination of the 2.5D hexagonally-packed structure with a monochromatic light source in transmission mode allowed reversible and quantitative measurements of variation in the glucose concentration based on first order lattice interspace tracking. Reversible covalent phenylboronic acid coupling with cis-diols of glucose molecules expanded the hydrogel matrix by ∼2% and 34% in the presence of glucose concentrations of 1 mM and 200 mM, respectively. A Donnan osmotic pressure induced volumetric expansion of the hydrogel matrix due to increasing glucose concentrations (1–200 mM), resulted in a nanoscale modulation of the lattice interspace, and shifted the diffraction angle (∼45° to 36°) as well as the interspacing between the 1st order diffraction spots (∼8 to 3 mm). The sensor exhibited a maximum lattice spacing diffraction shift within a response time of 15 min in a reversible manner. The developed 2.5D photonic sensors may have application in medical point-of-care diagnostics, implantable chips, and wearable continuous glucose monitoring devices