title: Quantification of penicillin G during labor and delivery by capillary electrophoresis.
abstract: In this study, a capillary electrophoresis (CE) method was developed as a means to measure levels of penicillin G (PCN G) in Group B Streptococcus (GBS) positive pregnant women during labor and delivery. Volunteers for this developmental study were administered five million units of PCN G at the onset of labor. Urine, blood, and amniotic fluid samples were collected during labor and post delivery. Samples were semi-purified by solid-phase extraction (SPE) using Waters tC18 SepPak 3cc cartridges with a sodium phosphate/methanol step gradient for elution. Capillary electrophoresis or reversed-phase high-performance liquid chromatography (RP-HPLC) with diode-array absorbance detection were used to separate the samples in less than 30 min. Quantification was accomplished by establishing a calibration curve with a linear dynamic range. The tC18 SPE methodology provided substantial sample clean-up with high recovery yields of PCN G ( approximately 90%). It was found that SPE was critical for maintaining the integrity of the separation column when using RP-HPLC, but was not necessary for sample analysis by CE where no stationary phase is present. Quantification results ranged from millimolar concentrations of PCN G in maternal urine to micromolar concentrations in amniotic fluid. Serum and cord blood levels of PCN G were below quantification limits, which is likely due to the prolonged delay in sample collection after antibiotic administration. These results show that CE can serve as a simple and effective means to characterize the pharmacokinetic distribution of PCN G from mother to unborn fetus during labor and delivery. It is anticipated that similar methodologies have the potential to provide a quick, simple, and cost-effective means of monitoring the clinical efficacy of PCN G and other drugs during pregnancy.
authors.affiliation: Department of Chemistry and Biochemistry, The University of Tulsa, 600 South College Avenue, Tulsa, OK 74104, United States.
authors.forename: Andrea
authors.initials: A
authors.lastname: Thomas
authors.forename: Omon K
authors.initials: OK
authors.lastname: Ukpoma
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Inman
authors.forename: Anil K
authors.initials: AK
authors.lastname: Kaul
authors.forename: James H
authors.initials: JH
authors.lastname: Beeson
authors.forename: Kenneth P
authors.initials: KP
authors.lastname: Roberts
mesh_terms: D002138:Calibration; D036861:Delivery, Obstetric; D019075:Electrophoresis, Capillary / Q000379:methods*; D005260:Female; D005333:Fetus / Q000378:metabolism*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007743:Labor, Obstetric; D010400:Penicillin G / Q000008:administration & dosage / Q000032:analysis* / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D011247:Pregnancy; D013292:Streptococcus agalactiae / Q000187:drug effects
chemical_list: D010400:Penicillin G