Determination and quantification of nine adulterant local anaesthetics in illegal treatments for male premature ejaculation by GC-FID and GC-MS

Objective: A gas chromatography (GC) method using flame ionization (FID) and mass spectrometry (MS) was developed and validated for the determination of nine local anaesthetics in counterfeit drugs sold illegally as treatments for male premature ejaculation. Methods: The GC-FID and GC-MS method validations demonstrated reliable specificity, selectivity, linearity, precision, and accuracy, and the validated methods were successfully applied to the analyses of collected samples. Results: Approximately 60% of the samples contained, at least, one of the local anaesthetics, which included menthol, 2-phenoxyethanol, eugenol, lidocaine, prilocaine, and tetracaine. Lidocaine was the most frequently detected compound in the analysed samples and occurred in a wide concentration range (2.81–52.40 mg/g). The concentrations of the detected compounds varied greatly between 0.03–52.40 mg/g. Conclusion: Continuous use of these counterfeit products, which contain high concentrations of local anaesthetics, can cause serious human health effects. Therefore, the continued screening of illegal products is required and our proposed methods could be used for the monitoring and quantification of local anaesthetics in counterfeit products. Keywords: Local anesthetics, Premature ejaculation, GC/FID, GC/MS, Adulterants, Validation.