Format

Send to

Choose Destination

RETRACTED ARTICLE

See: Retraction Notice

Arch Pharm Res. 2018 Apr;41(4):459-466. doi: 10.1007/s12272-018-1023-5. Epub 2018 Mar 23.

Analysis of loxoprofen in tablets, patches, and equine urine as tert-butyldimethylsilyl derivative by gas chromatography-mass spectrometry.

Author information

1
College of Pharmacy and Research Institute of Life and Pharmaceutical Sciences, Sunchon National University, Suncheon, 540-950, Republic of Korea.
2
Jeonbuk Branch Institute, Korea Research Institute of Bioscience and Biotechnology, Jeonbuk, 56212, Republic of Korea.
3
Department of Physiology and Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, 443-749, Republic of Korea.
4
Racing Laboratory, Korea Racing Authority, Gwacheon, 13822, Republic of Korea.
5
College of Pharmacy, Chosun University, Gwangju, 501-759, Republic of Korea. wlee@chosun.ac.kr.
6
College of Pharmacy and Research Institute of Life and Pharmaceutical Sciences, Sunchon National University, Suncheon, 540-950, Republic of Korea. paik815@sunchon.ac.kr.

Abstract

Loxoprofen is a non-steroidal anti-inflammatory drug of the 2-arylpropionic acid type, which has used to treat musculoskeletal disorders in the horse racing industry. However, it has also used illicitly to mask clinical signs of inflammation and pain in racehorses. Thus, its accurate analysis has become an important issue in horse doping laboratories. In this study, an analytical method of loxoprofen was developed as tert-butyldimethylsilyl (TBDMS) derivative by gas chromatography-mass spectrometry (GC-MS). Characteristic fragment ions of [M-15], [M-57], and [M-139] permitted the accurate and selective detection of loxoprofen. Under optimal conditions, this method showed good linearity (r ≥ 0.999) in the range of 10-500 ng/mL, repeatability (% relative standard deviation = 5.6-8.5), and accuracy (% relative error = - 0.3-0.9) with a detection limit of 1.0 ng. When applied to the analysis of loxoprofen in tablet and patch products, loxoprofen was positively identified as TBDMS derivative by GC-MS. The present method provided rapid and accurate determination of loxoprofen in patch and tablet products. Levels of loxoprofen were highest in equine urine at 0.5 and 1 h after oral administration with single dose (3 mg/kg) to three horses, and then rapidly reduced to below the lower limit of quantification at 24 h. Therefore, the present method will be useful for the pharmacokinetic study and doping tests for loxoprofen and other similar acidic drugs in horses.

KEYWORDS:

Equine urine; Gas chromatography-mass spectrometry; Loxoprofen; Patch; Tablet; tert-Butyldimethylsilyl derivative

PMID:
29572683
DOI:
10.1007/s12272-018-1023-5
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Springer
Loading ...
Support Center