advertisement
Abstract #5435 Published in IGR 1-2
Population pharmacokinetics of 2% topical dorzolamide in the aqueous humor of humans.
Schmitz K; Banditt P; Motschmann M; Meyer FP; Behrens-Baumann WInvestigative Ophthalmology and Visual Science 1999; 40: 1621-1624
PURPOSE: To evaluate the concentration and kinetics of dorzolamide in the aqueous humor after its topical application. METHODS: Samples of aqueous humor were collected at the beginning of routine cataract surgery at defined intervals after topical application of a 2% solution of dorzolamide. After deep-frozen storage of the samples, drug extraction was achieved with a mixture of solvents. Quantification was carried out by high-performance liquid chromatography on a reversed-phase column. RESULTS: Peak concentrations of dorzolamide in aqueous humor were reached approximately 2 hours after application with 1000 ng/ml. Average values were approximately 1000 to 700 ng/ml after 4 to 6 hours and approximately 200 ng/ml after 12 hours. Mean half-life of absorption was 1.2 hours and for elimination 3.0 hours. CONCLUSIONS: Pharmacokinetics of dorzolamide in the aqueous humor of humans are in comparable dimensions as previously reported in experimental trials in pigmented rabbits. There is a clear linear absorption and elimination kinetic, which is demonstrated using the Bateman function. A better knowledge of the distribution and kinetics of dorzolamide will help to explain its reported effects on intraocular hemodynamics, distinct from its intraocular pressure lowering effect.
Eye Department, Otto-von-Guericke-University, Magdeburg, Germany.
Classification:
11.5.2 Topical (Part of: 11 Medical treatment > 11.5 Carbonic anhydrase inhibitors)
