RESUMEN
A high-performance liquid chromatographic method for the simultaneous determination of phenylephrine and tropicamide in human aqueous humor was developed. After centrifugation, an aliquot of the supernatant was injected onto the column and the eluent was monitored at 280 nm then 254 nm after 5 min. Separation was performed on a CN column with 0.01 M Pic B8 (octane sulfonic acid)-acetonitrile (65:35, v/v) as mobile phase. The standard curves were linear in the detection range. The precision of the method (expressed by relative standard deviation) and the accuracy (mean error in per cent) were <5% for both intra- and interassays.
Asunto(s)
Humor Acuoso/química , Cromatografía Líquida de Alta Presión/métodos , Antagonistas Muscarínicos/análisis , Midriáticos/análisis , Fenilefrina/análisis , Tropicamida/análisis , Humanos , Sensibilidad y EspecificidadRESUMEN
A simple and sensitive HPLC method for determination of metronidazole in human plasma has been developed. A step of freezing the protein precipitate allowed an efficient separation of aqueous and organic phases minimizing the noise level and improved therefore the limit of quantitation (10 ng ml(-1) using 1 ml of plasma sample). The separation of compounds was performed on a RP 18 column with acetonitrile-aqueous 0.01 M phosphate solution (15:85, v/v) as mobile phase. Detection was performed by UV absorbance at 318 nm. Metronidazole was well resolved from the plasma constituents and internal standard. An excellent linearity was observed between peak-height ratios plasma concentrations over a concentration range of 0.01 to 10 microg ml(-1). Within-day and between-day precision (expressed by relative standard deviation) and accuracy (mean error in per cent) did not exceed 4% between 1 and 10 microg ml(-1) and 8.3 and 7.2% respectively for the limit of quantitation. The method is suitable for bioavailability and pharmacokinetic studies in humans.