Bernauer W, Thiel MA, Rentsch KM. Phosphate concentration in ophthalmic corticoid preparations.
Graefes Arch Clin Exp Ophthalmol 2008;
246:975-8. [PMID:
18357463 DOI:
10.1007/s00417-008-0788-5]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Revised: 02/01/2008] [Accepted: 02/06/2008] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND
Topical preparations, high in phosphate, may cause calcification when used on a damaged corneal surface. The knowledge of the phosphate concentration in medications helps to prevent corneal calcifications. Our study gives an overview of the amount of phosphate contained in ophthalmic corticoid preparations.
METHODS
Samples of 38 commercially available corticoid preparations were tested. The quantification of phosphate was performed using the molybdate method on a Modular P autoanalyzer.
RESULTS
18 of 38 preparations (47%) had a phosphate concentration above physiological levels (>1.45 mmol/l). It varied greatly, and ranged from less than 0.1 mmol/l (18 preparations) to 62.6 mmol/l. The corticoids that were tested included betamethasone sodium phosphate (18.3-35.5 mmol/l), dexamethasone (0.1-17.6 mmol/l), dexamethasone sodium phosphate (<0.1-62.6 mmol/l), fluorometholone (<0.1-22.5 mmol/l), and prednisolone acetate (<0.1-0.5 mmol/l).
CONCLUSIONS
The phosphate concentration in corticoid-phosphate formulations varies greatly, and is mainly determined by the chosen buffer. The prednisolone acetate preparations showed physiological phosphate concentrations. For a treatment on a damaged corneal surface, preparations with physiological phosphate concentrations should be used.
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