HPLC Method with Solid-Phase Extraction for Determination of (R)- and (S)-Ketoprofen in Plasma without Caffeine Interference: Application to Pharmacokinetic Studies in Rats

Abstract

A fast and reproducible high-performance liquid chromatography method has been developed for the determination of (R)- and (S)-ketoprofen. Ketoprofen enantiomers were determined in plasma samples (50 µL), after solid-phase extraction, using diclofenac as internal standard. Analyses were performed on a (S, S)-Whelk-O 1 stainless steel column (5 µm, 250 × 4.6 mm) using hexane-ethanol-acetic acid (93:7:0.5, v/v/v) as the mobile phase and detection at 254 nm. The method was selective for ketoprofen enantiomers in the presence of caffeine and endogenous plasma compounds. Standard curves were linear (R(2) > 0.999) over the concentration range of 0.25-12.50 and 0.25 µg/mL was taken as the limit of quantification. The intra- and interday precision (relative standard deviation) values were <15.0% and the accuracy (relative error) was within ±12.0% at 1.0, 5.0 and 10.0 µg/mL. Enantiomer recoveries yielded 100.0 ± 15%. No significant differences were determined in plasma samples stored at room temperature for 24.0 h, after two freeze-thaw cycles, and between 0 and 4 weeks at -20°C (P > 0.05). The validated method was successfully applied in determination of (S)-ketoprofen in Wistar rats after oral administration of 3.2 mg/kg of (S)-ketoprofen alone or 3.2 mg/kg of (S)-ketoprofen + 17.8 mg/kg of caffeine.

Pharmacokinetics and Pharmacodynamics of (S)-Ketoprofen Co-Administered with Caffeine: A Preclinical Study in Arthritic Rats

“…In humans, rats, and mice, absorption is not stereoselective [ 35 ]. The pharmacokinetics of ( S )-ketoprofen alone and in combination with caffeine have been previously determined in other studies [ 31 ]. After administration of a single dose of 3.2 mg/kg of ( S )-ketoprofen or 3.2 mg/kg of ( S )-ketoprofen + 17.8 mg/kg of caffeine to Wistar rats, significant differences in C max and AUC 0-∞ of ( S )-ketoprofen were found ( p < 0.05).…”

“…Extraction of ( S )-ketoprofen from plasma samples was conducted using a solid-phase extraction (SPE) technique previously developed in our laboratory [ 31 ]. Briefly, the cartridges (Strata-X 33 µm polymeric reversed phase cartridge, Phenomenex, Torrance, CA, USA) with the aid of a vacuum device (Vac-Elut, Speed Mate 10, Applied Separations Inc., Allentown, PA, USA) were preconditioned by flushing with 2 mL of methanol and 1 mL of high-performance liquid chromatography (HPLC) water.…”

“…( S )-ketoprofen plasma concentrations were determined by HPLC analysis with ultraviolet (UV) detection [ 31 ]. The chromatographic system consisted of a Perkin Elmer Series 200 HPLC (Norwalk, CT, USA) equipped with a binary pump, a manual injector with a 20 μL loop, and a variable wavelength UV 785 model detector (Applied Biosystems, Foster, CA, USA).…”

A molecularly imprinted polymer as solid phase extraction sorbent for ketoprofen determination in water and artificial serum prior to HPLC

“…Generally, it is determined by chromatographic techniques including gas chromatography [ 9 ], high performance liquid chromatography [ 10 ], and capillary electrochromatography [ 1 , 11 ]. Detection of ketoprofen in the aquatic environment is difficult due to its trace amounts, and complex matrices of waters which necessitate the application of sample pretreatment step(s) prior to chromatographic analysis [ 12 ].…”

Quantitative Analysis of Ketoprofen Enantiomers by Liquid Chromatography/Electrospray Ionization-Mass Spectrometry

“…Carefully monitoring the action of NSAIDs is therefore crucial with a view to improving the toxicological management of logn-term NSAIDs therapies. A number of High performance liquid chromatography (HPLC) [4][5][6] and capillary electrophoresis [7,8] methods for the determination of KET enantiomers in biological fluids [9].…”