Ultra-high performance liquid chromatography (UPLC) system can identify unauthorized drugs in health foods and herbal products used to treat gout and osteoporosis, according to study results published in Journal of Pharmaceutical and Biomedical Analysis.
Researchers developed and optimized a rapid, accurate method that simultaneously measured 20 anti-gout and anti-osteoporosis drug substances using a UPLC system, with a photodiode array detector. This method was validated according to the International Conference on Harmonization (ICH) Technical Requirements for Registration of Pharmaceuticals for Human Use guidelines (2005).
Chromatograms and spectra of each peak of the substances confirmed specificity. Solid and liquid blank samples evaluated the limit of detection and limit of quantitation (0.12-1.50 µg/mL and 0.36-4.50 µg/mL, respectively). Investigators obtained linearity from each calibration curve at 6 different concentrations, ranging from 1 to 20 times the limit of quantification of the drug substances.
After validating the method, the researchers analyzed 116 samples of health foods, herbal products, and seized forensic samples, which had been advertised as effective anti-gout and anti-osteoporosis agents. Among these 116 samples were 25 tablets, 28 capsules, 19 pills, 13 liquids, and 31 powders.
Researchers detected dexamethasone in 16 of the herbal food powder samples by comparing reference standard peaks with the unique spectrum at separate retention times with the unknown peak as dexamethasone.
In seized forensic samples, the researchers found concentrations of adulterants ranging from 0.013% to 0.022%.
“With the increasing interest in and use of dietary supplements in the treatments of age-related diseases associated with the bones and joints, adulteration with anti-gout and anti-osteoporosis drug substances could potentially pose a threat to public health,” the researchers wrote.
Kim NS, Kim J, Lim NY, Lee JH, Park S, Kang H. Simultaneous determination of illegal drug substances in dietary supplements for gout and osteoporosis using ultra-performance liquid chromatography and liquid chromatography-quadrupole-time-of-flight mass spectrometry. J Pharm Biomed Anal. 2020;179:113003.