Applicability of a Chemiluminescence Immunoassay to Screen Postmortem Bile Specimens and Its Agreement with Confirmation Analysis.

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.

Development and Validation of an HPLC-UV Method for the Quantification of Acyclovir and Ganciclovir in the Plasma of Pediatric Immunocompromised Patients.

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.

Quantification of 108 illicit drugs and metabolites in bile matrix by LC-MS/MS for the toxicological testing of sudden death cases.

Sudden death could occur after assumption of illicit drugs for recreational purposes in adults or after intoxication in children, and toxicological testing would help identify the cause of the death. Analytical methods sensitive and specific for the quantification of a great number of drugs and metabolites in at least 2 matrices should be used. Bile, collected postmortem, may be considered a specimen alternative to blood and urine to perform toxicological testing because of its extended detection window. The present study proposed a LC-MS/MS method to quantify 108 drugs and metabolites in bile. Compounds belonging to the drugs of abuse classes of amphetamines, benzodiazepines, cocaine derivatives, barbiturates, opioids, z-drugs, and psychedelics were analyzed. The sample preparation is simple and does not require solid-phase extraction. The proposed method showed an appropriate selectivity, specificity, accuracy, and precision of the calibrators and quality controls tested (precision < 15%; accuracy < 100 ± 15%). The sensitivity allowed to identify low amounts of drugs (e.g., morphine limit of detection = 0.2 µg/L; limit of quantification = 1.1 µg/L). There is no significant matrix effect, except for buprenorphine and 11-Nor-9-carboxy-Δ9-tetrahydrocannabinol. Carry-over was not present. Analytes were stable at least for 1 month at - 20 °C. Analyzing 13 postmortem specimens, methadone (50%), and cocaine (37.5%) resulted to be the most prevalent consumed substances; the concentrations quantified in bile resulted to be higher than the ones in blood suggesting bile as a potential new matrix for identifying illicit drugs and their metabolites.

Quantification of 7 cannabinoids in cannabis oil using GC-MS: Method development, validation and application to therapeutic preparations in Friuli Venezia Giulia region, Italy.

The use of therapeutic cannabis preparations in Friuli Venezia Giulia is increasingly expanding. Even if cannabis oil finds its applications in several disorders affecting adults and children, it is not yet a standardized product and, to ensure the quality of the preparation, a quantitative analysis must be carried out before dispensing it to patients. Gas chromatography coupled to mass spectrometry (GC-MS) is a frequently used technique for quantification of cannabinoids, the active compounds of C. sativa. In this context, we developed a GC-MS method for the simultaneous quantification of 7 cannabinoids (CBD, CBDA, CBG, CBN, THCA, THCV and Δ9-THC) that is not time and sample consuming: 10 µL of cannabis oil were used for the sample preparation, that consists in derivatization of analytes through silylation. Calibration curves were built from 0.2 to 2 µg/mL. The percentage of accuracy and precision did not exceed the values recommended by validation guidelines. The limit of detection was 0.01 µg/mL; whereas the lower limit of quantification was 0.2 µg/mL. There was no carry over. The proposed GC-MS method showed good sensitivity, specificity, linearity, accuracy, precision and applicability to therapeutic preparations.

A new proof of evidence of cysteamine quantification for therapeutic drug monitoring in patients with cystinosis.

BACKGROUND: To date, measurement of intracellular cystine is used for the therapeutic monitoring of patients affected by cystinosis in treatment with cysteamine. Since this method is time and sample consuming, development of a faster method to quantify cysteamine would be extremely useful in order to help clinicians to adjust dosages of cysteamine and to define better the pharmacokinetic profile of this drug. The aim of the study was to develop a liquid chromatography tandem mass spectrometry method for the quantification of cysteamine in plasma samples and to test its applicability on plasma samples derived from patients with nephropathic infantile cystinosis in treatment with cysteamine. RESULTS: The percentage of accuracy of the developed method varied between 97.80 and 106.00% and CV% between 0.90 and 6.93%. There was no carry over. The calibration curves were built from 2.5 to 50 µM. The limit of detection and the lower limit of quantification occurred at 0.25 and 1.25 µM respectively. Cysteamine was stable up to 2 months at -20 °C. Concentrations of cysteamine and intracellular cystine of 4 patients were in line with data previously reported. CONCLUSION: The proposed method showed an appropriate selectivity, specificity, linearity, sensibility, accuracy, precision and good applicability to samples.