Doseproportional pharmacokinetics ofalprostadil (prostaglandin E1)inhealthy volunteers following intravenous infusion

ionchemical ionization triple stage quadruple mass spectrometry, a highly specific andsensitive GC/MSJMS-method. During intravenous infusion of30,60and120jigPGE1,endogenous plasma PGE concentrations increased from1.7 ± 0.8to4.2 ± 1.1, 6.7 ± 1.0and11.0 ± 1.9pg mlrespectively. PGEoplasma concentrations increased fromendogenous levels of1.3 + 1.0pg ml-'to7.6 ± 2.1,14.1 ± 3.7and28.0 ± 3.0pg ml-'respectively, whilst 15keto-PGE0 plasma concentrations increased fromendogenous levels of10.2 ± 13.9pg ml-' to99.3 ± 27.9, 190.4 ± 52.5and357.2 ± 72.6pg ml-'respectively. Withinthe doserangeof30-120jgPGEI 2h-1 there was a linear increase ofCmaxandAUC withthedose. Theresults oftheanalysis ofvariance after baseline anddose-correctionshowa 90%confidence interval inthebioequivalence acceptance rangeof80to 125%.