Browse every published article, from the latest research to earlier analysis. Use the page numbers below to explore the complete archive.
A larger peak after sample preparation can reflect either more analyte reaching the instrument or a stronger instrument response to the same amount. Westland and Dormann examined that distinction while applying QuEChERS preparation to benzodiazepines in blood and urine. What the GC–MS experiment found The researchers observed increased apparent recoveries with external and internal standard…
A drug can be affected by an enzyme and also change how that enzyme handles other medicines. Townsend and colleagues used several phase 1 comparisons to investigate both directions for isavuconazole. When isavuconazole was the drug being measured With rifampin, isavuconazole exposure over a dosing interval was 90% lower under the tested regimen. In a…
A laboratory can validate a method to measure two medicines in a combination tablet. Applying the same method to blood introduces a new specimen with different potential interferences. Ashour and Kattan developed a high-performance liquid chromatography method for clidinium bromide and chlordiazepoxide in pharmaceutical preparations. What was validated in the tablet preparation The researchers used…
A lower serum concentration in a group prescribed a second drug can reflect how patients were selected or treated. A retrospective analysis by Jiang and colleagues examined this question using clozapine and its metabolite norclozapine. What the serum study found The researchers reviewed serum concentrations and clinical records from 341 patients with schizophrenia. In their…
A syringe concentration describes what was prepared. Measurements at the far end of the tubing can answer a different question. A laboratory study by Maiguy-Foinard and colleagues tested this distinction using eight commercially available double-lumen extension sets. What the researchers measured The researchers infused diazepam through sets made with different plastics and sampled the fluid…
A concentration peak in hair can look like a timestamp. A review by Shima and colleagues illustrates why the number of peaks can be misleading when a laboratory is trying to distinguish one exposure from several.
The key observation was the sequence Walton and colleagues described three dogs younger than five months that required mechanical ventilation for severe hypoxemia. Each received a continuous benzodiazepine infusion as part of sedation. Generalized seizures appeared within 36 hours after sedation stopped and the dogs were weaned from ventilation. The seizures were managed with a…
Two measures from one concentration curve A phase 1 interaction study used midazolam as a probe of CYP3A activity. Thirty healthy volunteers took a 4 mg oral dose of midazolam alone and, after a washout and repeated eluxadoline doses, took the same midazolam dose alongside eluxadoline. The comparison used each participant as their own reference,…
What the laboratory measured Fernández-López and colleagues applied a gas chromatography–mass spectrometry method to detect carbamazepine in human bone in a forensic case. They removed surface soft tissue, dried and pulverized the bone, then extracted the resulting powder. Their identification criteria included retention time and the relative responses of characteristic ions. The paper also reports…
The lab deliberately added a reference compound Wu and colleagues developed a liquid chromatography tandem mass spectrometry assay for the EGFR inhibitor AZD-3759 in rat plasma. Diazepam served as the internal standard. The calibration related the AZD-3759 peak area to the diazepam peak area, using known AZD-3759 concentrations to establish the relationship. The two signals…
Particle count depends on the reporting window Benlabed and colleagues ran six-hour bench simulations of simultaneous ICU infusions. The regimens included midazolam along with several other therapies. The investigators used dynamic imaging to count particles and reported the size distribution, including counts at the 10 and 25 micrometer thresholds used for comparison with pharmacopeial reporting.…
Check the denominators before dividing The Milan autopsy series reported mean cocaine concentrations of 5.37 µg/mL in cardiac blood and 5.28 µg/mL in femoral blood in a category of 15 acute single-substance intoxication deaths. Table 1 rounded the ratio of those two means to 1.0. Its footnotes show that the cardiac mean used 13 cases…
Two blood draws gave different views of exposure Mohamed and colleagues followed 33 patients using cannabinoid preparations for neurological care. Sixteen used an oromucosal spray and 17 used oil-based preparations. The investigators measured plasma THC and CBD immediately before the morning dose and again 2.5 hours after dosing. For 45% of patients, both trough results…
Targeted and untargeted data answer different questions Monti and colleagues analyzed flower from 18 cannabis varieties grown under standardized conditions. Their targeted high-resolution mass spectrometry workflow measured a panel of 15 cannabinoids. A parallel untargeted workflow detected 19 additional compounds and used computational tools to help assign structures. This produced a richer fingerprint for comparing…
One extract, different concentration ranges A cannabis flower extract can contain abundant THC or CBD alongside much smaller amounts of other cannabinoids. McRae and Melanson validated an LC–MS/MS method for 17 cannabinoids and addressed that range with more than one dilution. Diluting the extract brings abundant analytes into the working range. An undiluted or less…
A syringe can retain its original drug concentration even when a separate question about sterility remains unanswered. Anderson and MacKay tested chemical stability for several medications stored individually in polypropylene syringes. What the study assayed The researchers used liquid chromatography with diode-array detection to measure concentrations initially, around day 50 and at day 100. Both…
A programmed infusion rate, an alert and the amount actually delivered are distinct records. A review of smart syringe pumps used in dental sedation explains the difference between soft alerts and hard limits in a drug library. What the alert means The review explains that a soft alert can be overridden by the operator, allowing…
Measurements made while a compound is present can differ from measurements after the compound is removed. Martínez and colleagues tested that distinction when studying cannabidiol and HLA-G, an immune-regulatory protein, in a choriocarcinoma cell line. Measuring expression during and after exposure The team exposed JEG-3 cells to CBD or a high-CBD extract. They measured HLA-G…
A certificate that reports CBD as a percentage describes concentration in the sampled material. To compare the amount of CBD produced by two crops, the weight of harvested material matters too. An indoor cannabis experiment showed how those measures can move in opposite directions. What changed when fertilizer was reduced The investigators tested organic and…
Only five of 13 commercial e-liquids tested by Mazzetti and colleagues were within 10% of their labeled CBD concentration. The same paper showed that CBD could decline during controlled storage. Those observations address different questions: how the product tested when sampled and how an initially measured concentration can change over time. What the storage experiment…
A preoperative dose has a clock of its own. If absorption is still underway when anesthesia starts, a blood sample drawn at the end of a short operation can contain more midazolam than an earlier sample from the same patient.
A receptor subunit can affect both the timing of an inhibitory current and its response to a drug. Ye and colleagues tested those properties in a mouse preparation from the visual thalamus. What changed after the deletion The researchers selectively deleted the gamma-2 subunit in the dorsal lateral geniculate nucleus and recorded spontaneous inhibitory currents…
A leftover drink can be tested as a physical specimen. Its result answers a different question from a blood or urine test. What the bench study tested Soltaninejad and colleagues prepared nonalcoholic soft drinks spiked with six benzodiazepines, then analyzed them with high-performance liquid chromatography and ultraviolet detection. They reported recoveries of 93.7% to 108.7%…
A drug interaction study can report a higher peak concentration, greater total exposure or both. Those measures answer different questions about the concentration curve. Two endpoints from one probe experiment Armani and colleagues administered a cocktail of metabolic probes to healthy adults before and after a single 50 mg osilodrostat dose. Nineteen participants completed the…
A genotype can help frame a pharmacokinetic question. To explain a concentration from one critically ill child, an analyst also needs the conditions under which that concentration was measured. What the pediatric study compared The investigators genotyped 72 samples and examined relationships between CYP variants and midazolam pharmacokinetics. They reported an association between the CYP3A5…
A product made by chemically converting CBD may contain multiple compounds with similar names and structures. A laboratory reaction study characterized two additional products that can matter when identifying the peaks in a conversion mixture. Four structures in a laboratory experiment The researchers investigated CBD cyclization under different acid and solvent conditions. In addition to…
A solvent-saving extraction can recover the target cannabinoids while leaving a separate measurement problem. In a 2024 hemp-method study, the researchers found a strong matrix effect and changed the calibration design to account for it. How the researchers made a usable blank Mastellone and colleagues compared eutectic solvents for an ultrasound-assisted extraction. Their selected procedure…
A study protocol may list midazolam even when the main research question concerns anticoagulants. In the DOAC-Child protocol, midazolam had a separate purpose as a probe of drug-metabolizing enzyme activity.
A low drug concentration can reflect the sample’s history after collection. Charlier and colleagues tested how storage conditions affected cenobamate measurements while validating a human plasma assay.