Ibuprofen is widely used to reduce fever, pain, and inflammation and in the treatment of patent ductus arteriosus (PDA) in preterm infants. However, to study the impact of pharmacokinetics of ibuprofen on the rate of ductus arteriosus closure in humans, a quantitative method is required. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a highly sensitive, accurate, reliable, fast, and simple bioanalytical method. In this study, we developed and utilized an LC-MS/MS method to determine ibuprofen bioavailability. One of the novel aspects of this work is the small specimen volume required for the analysis (i.e., 50 µL). The calibration curve was linear across a concentration range of 0.15–50 μg/mL. The coefficient of variation for intra-day and inter-day precision was within 0.78%–7.21% and accuracy was within 97.52%–107.21% of the nominal values for low, medium, and high quality control (QC) concentration levels—QCL, QCM, and QCH (0.45, 9.0, and 40.0 μg/mL, respectively). For ibuprofen concentrations at the lower limit of quantitation (LLOQ), intra-day and inter-day accuracy were 98.11% and 99.81%, respectively; however, the intra-day and inter-day precision were 1.89% and 5.37%, respectively. The pharmacokinetic study involved 18 neonatal subjects who were grouped into low- or high-dose ibuprofen groups. The median maximum concentration for low- and high-dose regimens were 16.05 (14.21–19.32) and 24.10 (20.63–32.03) µg/mL, respectively, and the median elimination rate constant was 0.041 (0.026–0.047) and 0.071 (0.050–0.073) h⁻¹, respectively. Thus, the fully validated LC-MS/MS method was determined to be suitable for analyzing unknown plasma samples for ibuprofen pharmacokinetic, bioavailability, and bioequivalence studies.

布洛芬被广泛用于减少发热，疼痛和炎症，并用于治疗早产儿动脉导管未闭（PDA）。然而，为了研究布洛芬的药代动力学对人的动脉导管闭合率的影响，需要一种定量方法。液相色谱-串联质谱（LC-MS / MS）是一种高度灵敏，准确，可靠，快速而简单的生物分析方法。在这项研究中，我们开发并利用了LC-MS / MS方法来测定布洛芬的生物利用度。这项工作的新颖之处之一是分析所需的样品体积小（即50 µL）。校准曲线在0.15–50μg/ mL的浓度范围内是线性的。日内和日间精度的变异系数在0.78％–7.21％之内，精度在97.52％–107之内。低，中和高质量控制（QC）浓度水平（QCL，QCM和QCH）的标称值的21％（分别为0.45、9.0和40.0μg/ mL）。对于布洛芬浓度下限（LLOQ），日内和日间准确度分别为98.11％和99.81％；但是，日内和日间精度分别为1.89％和5.37％。药代动力学研究涉及18位新生儿，这些受试者被分为低剂量或高剂量布洛芬组。低剂量和高剂量方案的最大中位数浓度分别为16.05（14.21–19.32）和24.10（20.63–32.03）µg / mL，中位数消除率常数分别为0.041（0.026-0.047）和0.071（0.050- 0.073）小时 对于布洛芬浓度下限（LLOQ），日内和日间准确度分别为98.11％和99.81％；但是，日内和日间精度分别为1.89％和5.37％。药代动力学研究涉及18位新生儿，这些受试者被分为低剂量或高剂量布洛芬组。低剂量和高剂量方案的最大中位数浓度分别为16.05（14.21–19.32）和24.10（20.63–32.03）µg / mL，中位数消除率常数分别为0.041（0.026-0.047）和0.071（0.050- 0.073）小时 对于布洛芬浓度下限（LLOQ），日内和日间准确度分别为98.11％和99.81％；但是，日内和日间精度分别为1.89％和5.37％。药代动力学研究涉及18位新生儿，这些受试者被分为低剂量或高剂量布洛芬组。低剂量和高剂量方案的最大中位数浓度分别为16.05（14.21–19.32）和24.10（20.63–32.03）µg / mL，中位数消除率常数分别为0.041（0.026-0.047）和0.071（0.050- 0.073）小时 药代动力学研究涉及18位新生儿，这些受试者被分为低剂量或高剂量布洛芬组。低剂量和高剂量方案的最大中位数浓度分别为16.05（14.21–19.32）和24.10（20.63–32.03）µg / mL，中位数消除率常数分别为0.041（0.026-0.047）和0.071（0.050- 0.073）小时 药代动力学研究涉及18位新生儿，这些受试者被分为低剂量或高剂量布洛芬组。低剂量和高剂量方案的最大中位数浓度分别为16.05（14.21–19.32）和24.10（20.63–32.03）µg / mL，中位数消除率常数分别为0.041（0.026-0.047）和0.071（0.050- 0.073）小时^-1。因此，经充分验证的LC-MS / MS方法适合用于分析未知血浆样品，用于布洛芬药代动力学，生物利用度和生物等效性研究。