Identification and Quantification of Ibuprofen in Blood Using HPLC-UV/Vis.

Abstract

Non-steroidal anti-inflammatory drugs are some of the most frequently used medications in the United States. Ibuprofen is a common over-the-counter nonnarcotic analgesic, and it is also typically used as an antipyretic and as an anti-inflammatory. Intentional or unintentional ibuprofen overdose is common but typically found to be non-life threatening. If a victim had decreased hepatic or renal function, however, ibuprofen overdoses may impart significant toxicity, and at high dosages, it has been linked to cardiovascular events. Currently, the Sedgwick County Regional Forensic Science Center (RFSC) sends postmortem samples to a contract laboratory if ibuprofen toxicity is suspected. The purpose of this project is to develop and validate a method for the detection and quantitation of ibuprofen for RFSC using High Performance Liquid Chromatography (HPLC) with a UV/Vis detector. Ibuprofen and an internal standard, o-toluic acid were added to negative blood and extracted using acetate buffer (pH 4.5) and ethyl acetate/ hexane 50/50 over a range of concentrations (40 mg/L – 450 mg/L). Using the Breeze 2 software package, a calibration curve was generated and various test concentrations were quantitated. The method was validated in accordance with the Scientific Working Group for Forensic Toxicology (SWGTOX) guidelines. Actual concentrations (as measured by the Breeze 2 software) were within ±20% of the expected concentrations. This method is a cost-effective option for rapid ibuprofen analysis.