Phosphorimetric Determination of Indomethacin in Pharmaceutical Formulations

Abstract

A simple, rapid and sensitive method for the determination of indomethacin was developed based on solid-surface room-temperature phosphorimetry. Phosphorescence emission was induced by the indomethacin hydrolysis reaction in a basic medium. Chromatography paper treated for background reduction was employed as a solid substrate. The use of four heavy-atom salts and sodium dodecyl sulfate was optimized to estimate an absolute limit of detection at the subnanogram level. A calibration curve with a linear dynamic range extending over two orders of magnitude (3.0 x 10(-7)-1.0 x 10(-4) mol dm-3) was obtained. The recovery of the method (98.4 +/- 6.8%) was tested using commercial formulations containing indomethacin as the only anti-inflammatory agent.

Determination of Indomethacin by Room-Temperature Phosphorimetry on a Polyvinyl alcohol) Substrate

“…In the spectrum of hydrolyzed IM, there are two emission peaks at λex,em = 297,450 nm and λex,em = 242,440 nm, attributed to IM-MMAA and IM-PCBA, respectively. The assignment of each peak was confirmed by a comparison with data in a previous report on IM-MMAA, 6 and by the measurement of an authentic sample of PCBA, as shown in Fig. 1.…”

“…6 In our investigation, IM was hydrolyzed by NaOH. With regard to IM-MMAA, the RTP properties were previously studied on a paper substrate, 6 whereas those for IM-PCBA have not yet been studied. Figure 1 shows the three-dimensional phosphorescence spectra of hydrolyzed IM by NaOH and purchased PCBA.…”

“…[6][7][8][9] The optimum concentration of SDS with KI on the PVA substrate was investigated by monitoring the RTP signal of IM-MMAA as a function of the SDS concentration. The result is shown in Fig.…”

“…Campiglia et al have already reported on a simple, rapid, sensitive, and accurate method for the determination of IM in pharmaceutical formulations based on paper substrate RTP. 6 They attempted the RTP detection of IM via one of its indole hydrolysis products, 5-methoxy-2-methylindole-3-acetic acid (IM-MMAA).…”

Electrooxidation of Indomethacin at Multiwalled Carbon Nanotubes-Modified GCE and Its Determination in Pharmaceutical Dosage Form and Human Biological Fluids

“…Until now, the most common techniques for the determination of INM in commercial dosage form were based on spectrofluorometric [2], phosphorimetric [3], spectrophotometric [4], preconcentration, and voltammetric [5], chemometric near infrared spectroscopy and X-ray powder diffractometry [6], photofluorometric [7], and high-performance liquid chromatographic (HPLC) methods [8]. But these methods are time consuming, are solvent usage intensive, and require expensive devices and maintenance.…”