Topical drug delivery devices: A review

For the treatment and prevention of ocular diseases, most patients are treated with conventional drug delivery formulations such as eye drops or ointments. However, eye drops and ointments suffer from low patient compliance and low effective drug concentration at the target site. Therefore, new medical devices are being explored to improve drug delivery to the eye. Over the years, various delivery devices have been developed including resorbable devices, oval- and ring-shaped devices, rod-shaped devices, punctum plugs, contact lenses and corneal shields. Only a few devices (eg. Mydriasert(center dot), Ozurdex(center dot), Surodex(center dot), Iluvien(center dot), Lacrisert(center dot) and Retisert(center dot)) have made it to the market while others are being investigated in clinical trials. Altogether, there is a need for enhanced topical drug delivery. Only by working together (academia, industry and authorities) and by exploring parallel strategies (new drug delivery devices, enhanced drug formulations, better understanding of the pharmacokinetic properties), the therapeutic effect of drug treatments can be improved.