New technique to use IOLs as drug delivery systems
An innovative process using supercritical fluid technologies offers the potential for the
impregnation of IOLs with steroids and antibiotics, said Elisabeth Badens PhD, Aix
Marseille University, France.
“The resulting impregnated IOLs do not contain residual organic solvent traces and they
can act as drug delivery systems once placed in the eyes at the end of surgery,” she told
the 18th ESCRS Winter Meeting .
She described a series of experiments in which she and her associates used supercritical
carbon dioxide in a super critical fluid state as a vehicle with which to impregnate
commercially available PMMA rigid IOLs and foldable hydrophilic IOLs with
dexamethasone.
Dr Badens explained that a supercritical fluid is a compound brought to a pressure higher
than that necessary to change it from a gas to a liquid when at a temperature above
which it cannot be an ordinary liquid no matter how much pressure is applied. As a result
it has a liquidlike density and a gaslike viscosity.
She noted that they were able obtain significant impregnation rates of the steroid in the
IOLs using the technique while also preserving the transparency and optical properties of
the lens material. In addition, they were able to show in an in vitro study that the
impregnated drug passed into an aqueouslike fluid surrounding the IOLs over periods
ranging from ten and thirty days.
“Supercritical technologies can be adapted to any polymeric matrix or implant for which
drug impregnation is required and can also be used to impregnate the material with a
mixture of drugs,” she added.
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