Indomethacin, detection

Following oral administration of indomethacin to chickens at a dosage of 2 mg/kg bw, significant levels of indomethacin residues were detected in liver, muscle, and fat of treated birds (101). However, 24 h after administration, tissue concentrations declined to very low levels and even undetectable in some animals. 

Despite the resolving power of TLC-MS-MS, few applications in drug residue analysis have been reported. One application concerns the HPTLC-MS-MS analysis of a number of nonsteroidal anti-inflammatory drugs, including salicylic acid and its glycine conjugate salicylhippuric acid, diclofenac, indomethacin, naproxen, phenacetin, and ibuprofen (67). Another application describes the detection and identification of some of these compounds or their metabolites in urine by TLC-MS-MS (67). 

Lei et al. and Nie et al. [110, 111] have reported two assays for indapamide and indomethacin, respectively, also based on luminol as chemiluminescent reagent. Again MAA and EGDMA were used as monomers and acetonitrile as porogen. Excellent detection limits were achieved 10 x M for indapamide and indomethacin in urine and 10-9 M for epinephrine in serum. The authors describe the crossreactivity for other contaminants potentially present in urine such as antibiotics (norfloxacin), ions (Fe2+, Ca2+, K+), or glucose. 

The indomethacin hydrolysis product 2-methyl-5-methoxy indole acetic acid fluoresces at 385 nm after excitation at 300 nm in 0.1N NaOH,(41) and at 387 nm after excitation at 312 nm in pH 11.6 buffer(42). The latter procedure claimed a threefold increase in detectability. Neither method distinguishes indomethacin from salicylates. Clinical studies employing subjects administered aspirin must use a separation prior to fluorescence analysis. Without adequate separation the indole metabolites as well as salicylate, produce a positive assay bias. 

A highly sensitive and specific ELISA for the determination, in different types of water samples, of diclofenac, a commonly used nonsteroidal anti-inflammatory drug (NSAID), has been developed by Deng et al.357 This analyte belongs to the most frequently detected, pharmaceutically active compounds in the water cycle. The immunoassay was able to measure tap water samples directly— respective LOD and IC50 values were 6 and 60 ng E. On the other hand, surface water samples required fivefold dilution and the wastewater samples 10-fold dilution in buffer to be analyzed correctly the LODs were then 20 and 60 ng E, respectively. Recently, the development and validation of a highly sensitive and specific ELISA for the detection of pharmaceutical indomethacin in... 

High Pressure Liquid Chromatography. In plasma or urine indomethacin and desmethylindomethacin, sensitivity 25 ng/ml for indomethacin in plasma, fluorescence detection—M. S. Bernstein and M. A. Evans, J. Chromat., 1982, 229 Biomed. Appl., 18, 179-187. 

Zhang Y, Zhang Z, Song Y, Wei Y. Detection of indomethacin by high-performance liquid chromatography with in situ electrogenerated Mn(III) chemiluminescence detection. Anal Chim Acta 2007 582 229-34. 

Hypersil ODS (25 cm X 4 mm) 5 p,m Acetonitrile—acetate buffer (pH 4.8 or 4.2) UV, 254, 240, 280, 220, 260, 240, 280, and 360 nm The drugs were extracted with acetonitrile Detection limits ranged from 1 mg/L to 5 mg/L The mentioned detection wavelengths are for diflunisal, indomethacin, fenoprofen, ibuprofen, ketoprofen, naproxen, mefenamic acid, and piroxicam, respectively [11]... 

Plasma is vortex mixed with the IS (indomethacin for the determination of mefenamic acid or mefenamic acid for indomethacin in acetonitrile) and acetonitrile the mixture is centrifuged at 9,000 g for 3 min, and a portion of the supernatant liquid is evaporated to dryness the residue is dissolved in mobile phase Linearity 0.1-10 p-g/ml Detection limits 0.06 and 0.08 p,g/ml for indomethacin and mefenamic acid, respectively ... 

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