RESUMEN
Pyridostigmine bromide (PB) is a quartenary ammonium compound that inhibits the hydrolysis of acetylcholine by competitive reversible binding to acetylcholinesterase. PB is used for the symptomatic treatment of myasthenia gravis and has been applied as a prophylaxis against nerve agents. Many studies on PB have involved the reliance on techniques that extract and quantify PB in biological samples. This article presents an overview of the currently applied methodologies for the determination of PB and its metabolites in various biological samples. Articles published from January 1975 to the July 2005 were taken into consideration for the discussion of the metabolism and analytical method of PB. HPLC and GC methods have been used and discussed in most of the references cited in this review. Other methods such as RIA and CE that have been recently reported are also mentioned in this article. Basic information about the type of sample used for analysis, sample preparation, chromatographic column, mobile phase, detection mode and validation data are summarized in a table.
Asunto(s)
Inhibidores de la Colinesterasa/análisis , Bromuro de Piridostigmina/análisis , Animales , Inhibidores de la Colinesterasa/sangre , Inhibidores de la Colinesterasa/metabolismo , Cromatografía de Gases , Cromatografía Líquida de Alta Presión , Humanos , Miastenia Gravis/sangre , Plasma/química , Bromuro de Piridostigmina/metabolismo , Reproducibilidad de los Resultados , Orina/químicaRESUMEN
PURPOSE: To develop a high-performance liquid chromatography (HPLC) method with photodiode-array ultraviolet detection for the simultaneous determination of vitamin C, vitamin E and beta-carotene. METHODS: Following liquid-phase extraction from the human plasma samples, these three vitamins were successfully separated on the LiChrospher 100 RP-18 column (125 x 4 mm I.D.; particle size, 5 microm) at a flow-rate of 1.2 ml/min, with a mobile phase of methanol-acetonitrile-tetrahydrofuran (75: 20: 5, v/v/v). RESULTS: The limits of quantitation were 100, 0.25 and 0.25 microg/ml for vitamin C, vitamin E and beta-carotene respectively. The method is linear over the studied range of 0.25 to 5 g/ml for vitamin E and beta-carotene and 100 to 5000 microg/ml for vitamin C. The extraction recoveries were greater than 83% for these three vitamins. The within day and between-day precision of the analysis did not exceed 15.3 and 16.2%, respectively. CONCLUSION: A suitable method to determine the concentration of vitamin C, vitamin E and beta-carotene following oral administration of antioxidant supplement capsules to a healthy Chinese volunteer.