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Lack of a safe and convenient disposal method for expired and unused medications may lead to many problems such as accidental exposure, intentional misuse, and food and water contamination. Activated carbon can offer safe disposal of medications due to its highly porous structure, which exerts strong physical adsorption forces with chemicals. This study aimed to evaluate the efficiency of an activated carbon-based drug disposal system for deactivating three model sedative prescription medications. Deactivation was performed by mixing the medication, activated carbon, and tap water. Desorption was evaluated by exposing the deactivation system to wash-out solutions. Rapid, precise, accurate, and sensitive HPLC-UV method for each drug was successfully developed, validated and employed. Results of the 28-day deactivation study showed that on average, more than 94.00% of drugs were rapidly deactivated within 8 hours. All drugs reached more than 99.00% deactivation by the end of 28-day period. Desorption study demonstrated that all medications were retained by the system, with insignificant amount of drug (0.25%) leached into the washout solutions within 24 hours. In conclusion, activated carbon rapidly and successfully deactivated the medications tested, suggesting activated carbon-based drug disposal system provides a convenient, secure, and effective method for unused medication.

A novel method using ultra-high performance liquid chromatography coupled to hybrid quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap) was developed and validated for the simultaneous screening, identification and quantification of sedative-hypnotics in dietary supplements. Chromatographic conditions were optimised and a full data-dependent MS(2) scan (MS/dd-MS(2)) in positive and negative ion mode was used. A single injection was sufficient to perform the simultaneous screening and identification/quantification of samples. The response showed a good linear relationship with analyte concentrations over wide ranges (e.g., 1.0-1000 ng g(-1) for diazepam) with all the determination coefficients (r(2)) > 0.9985. The method was validated, obtaining accuracy (intra- and inter-day) in the range of 94.5-105.3% and precision (intra- and inter-day) in the range of 0.4-8.9%, respectively. The detection limits (LODs) were in the range of 0.3-1.0 ng g(-1) for different analytes. Recoveries were performed and ranged from 74.1% to 90.2%, while all matrix effects were over the range of 85.4-93.6%. Finally, this method was used to detect sedative-hypnotics in commercial dietary supplements. Of a total of 45 batches of dietary supplements, only three batches were found to be positive samples with concentrations of diazepam, clonazepam and alprazolam at high levels (≥ 8.22 mg g(-1)).