Microextraction by packed sorbent and high performance liquid chromatography determination of seven non-steroidal anti-inflammatory drugs in human plasma and urine.

This paper reports a new MEPS-HPLC-PDA method for the simultaneous analysis of seven non-steroidal anti-inflammatory drugs (Furprofen, Indoprofen, Ketoprofen, Fenbufen, Flurbiprofen, Indomethacin, and Ibuprofen) in human plasma and urine. NSAIDs were resolved on a Gemini C18 column (4.6 mm × 250 mm; 5 μm particle size) using a gradient elution mode with a run time of 25 min, comprising re-equilibration, without further purification. The method was validated over the concentration range from 0.1 to 10 μg/mL for all the analytes both in human plasma and urine, using Benzyl 4-hydroxybenzoate as the internal standards. This method was successfully tested to NSAIDs analyses in real matrices, in order to check the method potentiality and the correct response. The results from assay validations show that the method is selective, sensitive and robust. The limit of quantification of the method was 0.1 μg/mL for all analytes, and weighted-matrix-matched standard curves showed a good linearity up to 10 μg/mL. In order to check the correct response for over-range samples, parallelism tests were also assessed. In the entire analytical range the intra and inter-day precision (RSD%) values were ≤ 7.31% and ≤ 13.5%, respectively. For all the analytes the intra and inter-day trueness (Bias%) values ranged from -11.3% to 10.2%. To our knowledge, this is the first MEPS-HPLC-PDA based method that uses MEPS procedure for simultaneous determination of these seven NSAIDs in plasma and urine samples.