Solid phase membrane tip extraction - microemulsion electrokinetic chromatography of selected non-steroidal anti-inflammatory drugs

Abstract

Arylalkanoic acid drugs belong to the group of non-steroidal antiinflammatory drugs (NSAIDs). These drugs are often used for the treatment of fever and minor pain due to its capability to inhibit prostaglandin productions which act as a messenger molecule in human body. There are many methods used in previous research to analyse arylalkanoic acids drugs but most of the methods require high organic solvent consumption, time consuming and involve complex sample derivatization. Solid phase extraction (SPE) is the common method used for sample preparation of NSAIDs but also involves high organic solvent consumption and is time consuming. To overcome the problems, solid phase membrane tip extraction (SPMTE) coupled with microemulsion electrokinetic chromatography (MEEKC) were used in this study and its performance was evaluated. Under the optimum MEEKC and SPMTE conditions, good linearity was obtained in the range of 0.25 to 4.00 µg/mL with good coefficient of determination (r2 > 0.9985). Good repeatability was obtained with percentage relative standard deviation (% RSD) of 1.04 - 1.31% (n=3). Limit of detection (LOD) (S/N =3) was satisfactory for all the selected drugs (0.14 - 0.18 µg/mL). The average relative recoveries of the selected drugs in spiked water sample were good (99-104%). Combination of SPMTE procedure and the MEEKC method was then applied to the determination of spiked sulindac, ketorolac and aceclofenac in human urine samples. The percentage recoveries of the three NSAIDs obtained from the SPMTE-MEEKC method were good, ranging from 79 to 96%. Percentage relative standard deviation (% RSD), (n=3) for the extraction process was also good (< 3.7%). The result was then compared to SPE-MEEKC method. SPE-MEEKC method shows slightly higher percentage recovery (95 - 112%) and lower RSD % (n=3) (1.33 - 2.06%) than SPMTE-MEEKC method. The SPMTE-MEEKC method was proven to be applicable to human urine analysis of sulindac, ketorolac and aceclofenac with faster analysis time and low amount of organic solvent used than in SPE-MEEKC method.