# Nanobarrier contact lenses for mono and combination therapy for treating microbial keratitis

> **NIH NIH R21** · COLORADO SCHOOL OF MINES · 2024 · $243,325

## Abstract

Microbial keratitis (MK) is a serious ophthalmic infection that can cause visual impairment and even blindness. The MK
infection is commonly treated by the fourth-generation fluoroquinolones such as moxifloxacin or combination therapy
including tobramycin and vancomycin or gentamycin and vancomycin. The frequency of drop instillation for severe
infections is every 5 min for the first 30 min followed by half-hourly drops or hourly drops for the first 24-72 hours including
night. Subsequently, the frequency decreases to once every 2 or 4 hours. The high instillation frequency is required because
of rapid eye drop clearance resulting in a low bioavailability of 1-5%. The total number of drops for this therapy could be
as high as about 100 over 1-week of treatment. While efficacious, the patients have difficulties in complying with this high
frequency application of eye drops resulting in poor prognosis. We will address this unmet need by designing a novel
sustained release contact lens drug delivery system for delivering antibiotics (moxifloxacin (monotherapy) and tobramycin
and vancomycin (combination therapy)) to treat MK. Contacts lenses offer many advantages over eye drops including
extended release that will improve compliance by replacing 100 drops with 1-2 lenses and higher bioavailability that will
lead to higher and more consistent concentrations in ocular tissues resulting in improved therapy and reducing the possibility
of development of resistance that is becoming a major problem. We have developed a novel, patented approach for extended
delivery by incorporation of vitamin E (a tocopherol) nanobarriers in commercial silicone hydrogel contact lenses. Use of
commercial contact lenses that are already approved by the FDA reduces barriers to translation. Our preliminary results
have shown that nanobarrier contact lenses (NB-CL) increase the drug release duration of moxifloxacin, while maintaining
all key properties of the contact lenses including transparency, wettability, UV-blocking, oxygen and ion permeability, low
protein binding, and young’s modulus. Specifically, we showed that incorporation of 20% (w/w) on dry basis of vitamin E
in Acuvue Oasys lenses increases the release duration of moxifloxacin from a few hours to about 50 hours. Also, validated
mathematical model suggests that an Oasys lens loaded with 30% VE and 500 µg of moxifloxacin will result in drug
concentrations in aqueous humor comparable to the tedious drop regimen of numerous drops over 3 days. This research
aims to manufacture and characterize the antibiotic-loaded nanobarrier lenses in Aim 1 and test pharmacokinetics and
efficacy in New Zealand white rabbits in Aim 2. The approach will provide insights into sustained drug delivery and
efficacy with acute wear NB-CL, and lead to a novel device to treat MK. Our approach promises to increase bioavailability,
reduce dosage amount to improve compliance and minimize drug variations to reduce the potential for development o...

## Key facts

- **NIH application ID:** 10788841
- **Project number:** 1R21EY035764-01
- **Recipient organization:** COLORADO SCHOOL OF MINES
- **Principal Investigator:** ANUJ CHAUHAN
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $243,325
- **Award type:** 1
- **Project period:** 2024-03-01 → 2026-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10788841

## Citation

> US National Institutes of Health, RePORTER application 10788841, Nanobarrier contact lenses for mono and combination therapy for treating microbial keratitis (1R21EY035764-01). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10788841. Licensed CC0.

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