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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