|AU RESEARCH FOCUSED ON USING THE CONTACT LENS FOR DRUG DELIVERY
Contact lenses — the small marvel long appreciated by the
vision—impaired as being more worry-free than eyeglasses, may soon
serve as a drug delivery mechanism designed to provide relief from eye
irritations and diseases.
Researchers in Auburn University’s Department of Chemical Engineering
have developed a technology proven in laboratory testing to enable the
contact lens to hold medication in concentrated, renewable doses and
release the drug in a controlled, timed and targeted manner.
The result may be a significant improvement over the use of drops and
ointments, says the lead investigator, Mark Byrne, an AU assistant
professor of chemical engineering.
Since its inception, the hydrophilic (soft) contact lens has been
considered to have potential as an effective medication delivery
medium, Byrne says. The largest obstacle has been its limited capacity
to hold and release medication in an effective and controlled manner -
which has prevented any viable product showing up in the contact lens
“We have overcome those problems by improving the structural properties
within the polymer matrix of the gel that comprises the lens,” Byrne
said. “A contact lens is mostly water. To clean and rehydrate it, one
needs only to soak it in a saline-based cleaning solution. When the
lens is made of the right materials, this same process enables it to be
loaded with concentrated amounts of medication. Because it is easily
placed directly on the eye, the contact lens can thus become a very
effective medium for drug delivery.”
Byrne explains that the key is in matching engineering technology with
the science of biology. Although the AU technology uses materials no
different from those found in commercially available contact lenses,
Byrne says they have changed how those materials are incorporated into
the lens, but not in a way that requires changes in the lens
“This technology has a fundamental link to biology,” Byrne said. “We’ve
been able to match chemistry with the biology that comprises binding
properties and other biological mechanisms in the human body. The
result is a biometric polymer that binds with the desired medications
and provides a controlled, timed release of these medications. We’ve
not changed the material to a large extent. We've mostly changed the
synthesis of the material.”
Byrne says that 90 percent of the current eye treatment drugs available
are either drops or ointments. Neither is as effective in targeting as
“Typically, less than 7 percent of the applied drug is absorbed by the
eye tissue,” Byrne said about ointments and drops. “Because of that
poor absorption rate, the drug has to be applied in very high, multiple
dosages to be effective.”
Using the contact lens as the delivery mechanism, he says, enables the
drug to be administered at lower doses and with greater absorption by
the affected tissue, and with less impact on other untargeted tissues.
Byrne began his research focused on using the contact lens as a delivery mechanism for antihistamine.
“We found quickly-based on analysis of histamine action in the body -
that the contact lens could be made effective for antihistamine
delivery,” Byrne said.
He and his team - comprised of doctoral candidate Siddarth Venkatesh
and senior chemical engineering student Parker Sizemore - have now
expanded their research to examining the contact lens as a delivery
medium for anti-inflammatory drugs, antibiotics and other medications.
Auburn has filed for patent protection on Byrne’s technology.