Acyclovir and ganciclovir comprise the prophylaxis and treatment of herpesvirus and cytomegalovirus infections occurring in immunocompromised patients. Their therapeutic drug monitoring is fundamental because of interindividual variability leading to side effects and drug resistance and is performed through several techniques, such as liquid chromatography coupled with UV spectrophotometry (HPLC-UV) or mass spectrometry (LC-MS/MS). Therefore, we developed and validated a low-cost, non-time-consuming, and low-sample-consuming HPLC-UV method. Briefly, 100 µL of sample was used for sample preparation, mainly consisting of precipitation through organic solvent. In total, 20 µL was injected into the instrument. Chromatographic separation was obtained eluting mobile phases A (10 mM ammonium formiate 0.01% formic acid) and B (acetonitrile) on a Poroshell 120 SB-C8 2.1 × 150 mm, 2.7 µm for 12 min isocratically (97:3; A:B) at a flow rate of 0.2 mL/min. The linearity range (0.5–40 mg/L) of the method allowed us to quantify both the Cmin and Cmax of acyclovir and ganciclovir. Plasma concentrations measured on a small cohort of patients undergoing acyclovir (31) and ganciclovir (9) treatment by the proposed method and the LC-MS/MS methods, already in use, were significantly correlated. The proposed HPLC-UV method may be implemented in diagnostics as an alternative method in case of the unavailability of the LC-MS/MS system.

Background: Cannabis oil titration consists of quantification of the acidic precursors tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA) and their decarboxylated products, the active neutral cannabinoids delta-9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD), and is recommended to ensure galenic preparation quality through gas and liquid chromatography coupled with mass spectrometry (GC-MS; LC-MS). Analyses by LC-MS and GC-MS involving derivatization allow for detection of acidic and neutral cannabinoids; on the contrary, GC-MS without derivatization determines only neutral cannabinoids due to high temperature-decarboxylation occurring in the injection system. However, it is not clear if decarboxylation is complete. Methods: Different GC-MS methods with (BSTFA: TMCS and pyridine; incubation at 60 °C for 25 min) or without derivatization and an LC-MS method were developed for cannabinoid quantification. The total Δ9-THC and CBD yield of recovery were compared between the methods by testing laboratory samples with known concentrations of THCA and CBDA (total Δ9-THC and CBD: 175–351–702 ng/mL) and real cannabis oil samples (n = 6). Results: The total Δ9-THC and CBD yield of recovery were determined using LC-MS and GC-MS with derivatization, but not using GC-MS without derivatization (decarboxylation conversion rate of about 50–60%). No high deviation (<10%) in the total neutral cannabinoid concentrations in real cannabis oil samples was noticed, probably due to the low content of acidic forms in the original galenic preparation. Conclusions: This study raised awareness about the potential underestimation of the total Δ9-THC and CBD content in cannabis oils when quantification is performed by GC-MS without derivatization. The advice for pharmacists is to perform complete decarboxylation to convert all acidic precursors in neutral cannabinoids.

Bile has emerged as an alternative matrix for toxicological investigation of drugs in suspected forensic cases of overdose in adults and intoxications in children. Toxicological investigation consists in screening and, subsequently, confirming the result with specific techniques, such as liquid chromatography with tandem mass spectrometry (LC-MS/MS). As there is no screening test on the market to test postmortem bile specimens, the novelty of this study was in investigating the applicability of a chemiluminescence immunoassay, designed for other matrices and available on the market, on bile and validate its use, testing the agreement with LC-MS/MS analysis. Bile specimens were obtained from 25 forensic cases of suspected death from overdose and intoxication. Sample preparation for bile screening consists simply in centrifugation and dilution. Confirmation analysis allows simultaneous identification of 108 drugs and was validated on bile. Kappa analysis assessed a perfect agreement (0.81–1) between the assays for benzodiazepines, methadone, opiates, cocaine, oxycodone, cannabinoids, buprenorphine and pregabalin; a substantial agreement (0.41–0.6) was reported for barbiturates. No agreement was assessed for amphetamines, due to an abundance of putrefactive amines in postmortem specimens. In conclusion, this fast and easy immunoassay could be used for initial screening of bile specimens, identifying presence of drugs, except amphetamines, with reliability.