title: Gas chromatographic determination of pentoxifylline and its major metabolites in human breast milk.
abstract: A method has been developed for determination of the xanthine drug, pentoxifylline, and three of its metabolites (a secondary alcohol and two carboxylic acids) in human milk. The method requires pre-extraction with hexane to remove lipids followed by extraction with dichloromethane or dichloromethane-isopropanol (4:1). Absolute extraction recoveries were between 76-90%. Pentoxifylline and its alcohol metabolite (as the trifluoroacetate) and the carboxylic acid metabolites (as ethyl esters) were measured in separate gas chromatographic steps using a nitrogen detector. Determinations of pentoxifylline and its three metabolites were 96-99% accurate and standard deviations of 5-10% were observed for samples at or above the lower practical sensitivity limit (10 ng/ml) for the assay. Pentoxifylline and its metabolites were stable in breast milk for three weeks when stored at -15 degrees C.
mesh_terms: D001711:Biotransformation; D055598:Chemical Phenomena; D002621:Chemistry; D002849:Chromatography, Gas; D005260:Female; D006801:Humans; D008895:Milk, Human / Q000032:analysis*; D010431:Pentoxifylline / Q000032:analysis* / Q000378:metabolism; D012972:Sodium Hydroxide; D013805:Theobromine / Q000031:analogs & derivatives*
chemical_list: D012972:Sodium Hydroxide; D013805:Theobromine; D010431:Pentoxifylline