Maternal and fetal pharmacokinetics of moxalactam given intrapartum

Two grams of moxalactam was given intravenously to 28 women at high risk for infection following cesarean delivery. After a mean time of 48 minutes from infusion, maternal sera, cord sera, and uterine tissue obtained at delivery had concentrations of moxalactam of 62 micrograms/ml, 22.2 micrograms/ml, and 9.6 micrograms/gm, respectively. The maternal serum half-time was calculated to b e 2.1 hours. R and S epimeric distribution was determined in these sera and tissues, and the mean R/S ratios were 0.95, 0.93, and 1.22 for the three groups, respectively. The significance of these observations is discussed. A new method in which a high-pressure liquid chromatographic assay is used is described, and results are compared to those obtained with the microbiological assay. The high-pressure liquid chromatographic method was found to be quick, accurate, an reproducible.