Format

Send to

Choose Destination
Klin Monbl Augenheilkd. 2007 Apr;224(4):249-51.

Phosphate concentrations in antiglaucoma medication.

Author information

1
Department of Ophthalmology, University of Zürich, Zürich, Switzerland. wolfgang.bernauer@hin.ch

Abstract

BACKGROUND:

Eye drops may contain phosphates as part of their buffer system. In the presence of epithelial keratopathy a high concentration of phosphate favours corneal calcification. To date European legislation does not require a quantitative declaration of the phosphates since buffers are regarded as additives. The knowledge of the phosphate concentration in medications helps to prevent corneal calcifications. Our study gives an overview on the amount of phosphate contained in antiglaucoma drops.

METHODS:

21 samples of commercially available antiglaucoma drops were tested. The quantification of phosphate was performed using the molybdate method on a Modular P autoanalyzer.

RESULTS:

10 of 21 (47 %) glaucoma drops had a phosphate concentration above physiological levels (> 1.45 mmol/L). A concentration higher than 100 mmol/L was found in four preparations that contained timolol.

CONCLUSIONS:

Many antiglaucoma drops contain unphysiological levels of phosphate, very high concentrations are found in some beta-blockers. These preparations have the potential to favour the formation of insoluble crystalline calcium phosphate deposits when used on a damaged corneal surface, and should therefore be avoided.

PMID:
17458785
DOI:
10.1055/s-2007-962834
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Georg Thieme Verlag Stuttgart, New York
Loading ...
Support Center