Rapid detection of illegal selective androgen receptor modulators in unregistered supplements using a combination of selected solid-state analytical methods.

Background and purpose: Pharmaceutical crime is becoming an increasingly serious threat. For customs officers and police officers, minimal or no sample preparation before analysis is essential when detecting prohibited compounds/counterfeit products, ideally using on-site analysis. Experimental approach: Unregistered dietary supplements containing anabolic substances, specifically selective androgen receptor modulators (SARMs) such as andarine, ligandrol, ostarine, and testolone became the subject of investigation. Dietary supplements with these SARMs are often found illegally in various fitness centres and can be purchased online. Furthermore, these illegal supplements may not contain the declared SARMs at all or may contain incorrect amounts. Analytical methods such as Raman spectroscopy, differential scanning calorimetry, thermogravimetry, and X-ray powder diffraction were chosen to identify these banned SARMs in the illegal products. Key results: Using a combination of these fast and direct analytical techniques, in particular, Raman spectroscopy, it was found that out of 16 samples, SARMs were confirmed in 9 samples, while no testolone (4 samples), ostarine (2 samples), or andarine (1 sample) was reliably identified in 7 samples. Conclusion: Overall, almost half of the analyzed samples of unregistered/illegal sports dietary supplements purchased anonymously online in the Slovak Republic with declared content of at least one SARM did not contain what is declared on the label. Thus the combination of several solid-state analytical techniques without complex sample preparation has proven valuable for rapid identification of APIs in supplements.