Microplastics in Spanish Eye Drops: Hidden contaminants in ophthalmic formulations

Microplastics (MPs) are spread out in the environment and in several food, pharmaceutical, and caring products, which imply a high exposure to humans. In this regard, this study aimed to evaluate the presence of MPs in a type of ophthalmic product commonly used in Spain. Multi-use eye drops formulated by hyaluronic acid- and no hyaluronic acid-base were evaluated. As well as, three discarding modes (first drop, first five drops, and half content) were studied. Worryingly, the total eye drops sample contained MPs. Those MPs found present non-color, irregular fragments and film shapes with a majority size range of 11–30 μm. MPs were identified as polyethylene (PE) and polypropylene (PP) by micro-FTIR analysis. The interaction between MPs and the components of eye drops is discussed and correlated with the possible effects for eyes health. Moreover, dry eye syndrome is highly prevalent in Spain. The regular prescription of eye drops as a treatment, along with the presence of microplastics in these products has raised concerns about consumer health. It is a priority to prevent the indiscriminate misuse of these ophthalmic products, and in cases of use, it is recommended to adopt good practices as the recommended in this study.