The discussion about the use of preservatives in eye drops is still controversial, but more and more evidence supports the use of unpreserved eye drops for treatment of chronic diseases. For example, dry eye, a condition in which the tear film is impaired, is increasingly more recognized as an inflammatory disease. Treatment with preserved eye drops may worsen symptoms. For the treatment of mild symptoms, the use of non-irritating or unpreserved artificial tears is recommended, while as for more severe cases, the use of an anti-inflammatory principle will become the standard treatment.
The same recommendation for restricted use of preservatives applies for glaucoma, which requires a treatment for the rest of life. Baudoine et al have shown that the risks for glaucoma patients to experience severe local side effects increases with the number of preserved eye medications taken in parallel.1 Combination products that reduce the number of necessary medications or the use of unpreserved eye drops will certainly help suffering patients and will also increase adherence to the prescribed treatment schedule. At least in Europe, the authorities have recognized the issue, and the European Medical Agency (EMA) pushes, for example, the use of unpreserved ophthalmic formulations, most recently in a guideline on pediatric medicine.
Recognizing the trend toward preservative-free topical drugs, in 2006, Aptar Pharma started the development of the Ophthalmic Squeeze Dispenser (OSD), a multi-dose device designed for unpreserved eye drops.3 The system is designed in a common squeeze bottle shape to ensure user acceptance. The first commercial product registered under the European Medical Device Directive using the OSD as primary packaging was VISMED Multi, an artificial tear product by Swiss Eye Care expert TRB Chemedica, introduced to the market in 2011. To date, more than 25 million OSDs were sold as preservative-free multi-dose systems for several products, and many new projects are on the way. The key question we will answer in this review is how a single device can fit a wide range of formulations for different conditions and diseases?