Determination of ibuprofen in pharmaceutical formulations using time‐resolved terbium‐sensitized luminescence

Abstract

A sensitive and specific luminescence method for the determination of ibuprofen (IB) in pharmaceutical formulations in aqueous solution is described. The method is based on the luminescence sensitization of terbium (Tb(3+)) by formation of ternary complex with IB in the presence of tri-n-octylphosphine oxide (TOPO) and Tween-20 as surfactant. The luminescence signal for Tb-IB-TOPO is monitored at lambda(ex) = 229 nm and lambda(em) = 545 nm. Optimum conditions for the formation of the complex in aqueous system, were 16 mmol/L TRIS buffer, pH 5.7, TOPO 200 micromol/L and 15 micromol/L of Tb(3+), which allows for the determination of 9.7 x 10(-7) - 9.7 x 10(-6) mol/L IB with a detection limit of 1.2 x 10(-7) mol/L. The relative standard deviations of the method were <1.4%, indicating excellent reproducibility. The proposed method was successfully applied for the assays of IB in pharmaceutical formulations with average recoveries of 100.3-102.5%.

Properties of ibuprofen ion-selective electrodes based on the ion pair complex of tetraoctylammonium cation

“…This method does not involve any pretreatment (except filtration). Complex formationextraction or centrifugation steps are required with other instrumental methods [17][18][19]22,24,26].…”

“…The various methods include the use of spectrophotometry [15][16][17], spectrofluorimetry [18][19], high-performance liquid chromatography (HPLC) with UV detection [20], HPLC-ELSD (evaporative light scattering detection) [21], HPLC [22], potentiometric titration [23,24], conductometric titration [24], capillary electrophoresis [25], and luminescence [26].…”

Chemiluminescence determination of naproxen based on europium(III)‐sensitized KIO4–H2O2 reaction

“…[23] Ibuprofen, which also has an α,β-diketonates group, was reported to form a complex with terbium and was determined by sensitized fluorescence. [24] In this work, it was found that the formation of europium(III)-naproxen complex significantly enhanced the weak CL of KIO 4 -H 2 O 2 reaction. [25] Based on these observations, the experimental conditions that affected the CL reaction were carefully optimized using flow injection mode.…”

Determination of amlodipine using terbium‐sensitized luminescence in the presence of europium(III) as a co‐luminescence reagent

“…This phenomenon is called the “antenna effect” and such complexes are considered to be light conversion molecular devices because they are able to transform light absorbed by the ligand into light emitted by the ions via an intramolecular energy transfer process. As part of our ongoing interest on method development on drug analysis , we report a novel method for the assay of AM in pharmaceutical formulations and in biological fluids. The method is based on the luminescence enhancement and sensitization of terbium brought about by complexation with AM.…”