Antibiotic pharmacokinetics in infected pleural effusions.

Pleural infection is usually treated with empirical broad-spectrum antibiotics, but limited data exist on their penetrance into the infected pleural space. We performed a pharmacokinetic study analysing the concentration of five intravenous antibiotics across 146 separate time points in 35 patients (amoxicillin, metronidazole, piperacillin-tazobactam, clindamycin and cotrimoxazole). All antibiotics tested, apart from co-trimoxazole, reach pleural fluid levels equivalent to levels within the blood and well above the relevant minimum inhibitory concentrations.

Integrated and automated high-throughput purification of libraries on microscale.

We herein report the development of an automation platform for rapid purification and quantification of chemical libraries including reformatting of chemical matter to 10 mM DMSO stock solutions. This fully integrated workflow features tailored conditions for preparative reversed-phase (RP) HPLC-MS on microscale based on analytical data, online fraction QC and CAD-based quantification as well as automated reformatting to enable rapid purification of chemical libraries. This automated workflow is entirely solution-based, eliminating the need to weigh or handle solids.

Exploring the Pharmacokinetics of Phenoxymethylpenicillin (Penicillin-V) in Adults: A Healthy Volunteer Study.

This healthy volunteer study aimed to explore phenoxymethylpenicillin (penicillin-V) pharmacokinetics (PK) to support the planning of large dosing studies in adults. Volunteers were dosed with penicillin-V at steady state. Total and unbound penicillin-V serum concentrations were determined, and a base population PK model was fitted to the data.

Microneedle biosensors for real-time, minimally invasive drug monitoring of phenoxymethylpenicillin: a first-in-human evaluation in healthy volunteers.

Background: Enhanced methods of drug monitoring are required to support the individualisation of antibiotic dosing. We report the first-in-human evaluation of real-time phenoxymethylpenicillin monitoring using a minimally invasive microneedle-based β-lactam biosensor in healthy volunteers.

Methods: This first-in-human, proof-of-concept study was done at the National Institute of Health Research/Wellcome Trust Imperial Clinical Research Facility (Imperial College London, London, UK).

Challenges in the bioanalysis of tetracyclines: Epimerisation and chelation with metals.

Tetracyclines (TCs) are important broad spectrum antibiotics which are active against gram-positive and gram-negative bacteria. TCs readily form epimers, especially under weakly acidic conditions. The epimers are reported to have different antibacterial and toxicological properties and pose a significant challenge for selective bioanalysis, being isobaric with the parent drug and possessing very similar physicochemical properties.

Development, validation and application of a novel HPLC-MS/MS method for the measurement of minocycline in human plasma and urine.

New treatments are urgently required to treat infections caused by multi-drug resistant Acinetobacter baumanni,. To address this need, a new formulation of Minocin®, (minocycline for injection) has been developed that allows for higher doses of minocycline to be administered. Phase 1 clinical trials were conducted in healthy volunteers to assess the safety and pharmacokinetics (PK) of this new formulation at higher doses.

Development, validation and application of a novel HPLC-MS/MS method for the quantification of atorvastatin, bisoprolol and clopidogrel in a large cardiovascular patient cohort.

Cardiovascular disease is a leading cause of morbidity, mortality, and healthcare expenditure worldwide. Importantly, there is interindividual variation in response to cardiovascular medications, leading to variable efficacy and adverse events. Therefore a rapid, selective, sensitive and reproducible multi-analyte HPLC-MS/MS assay for the quantification in human plasma of atorvastatin, its major metabolites 2-hydroxyatorvastatin, atorvastatin lactone and 2-hydroxyatorvastatin lactone, plus bisoprolol and clopidogrel-carboxylic acid has been developed, fully validated, and applied to a large patient study.

The utility of HepG2 cells to identify direct mitochondrial dysfunction in the absence of cell death.

Drug-induced mitochondrial dysfunction has been hypothesized to be an important determining factor in the onset of drug-induced liver injury. It is essential to develop robust screens with which to identify drug-induced mitochondrial toxicity and to dissect its role in hepatotoxicity. In this study we have characterised a mechanistically refined HepG2 model, using a panel of selected hepatotoxicants and non-hepatotoxicants.

Automated approach for the rapid identification of purification conditions using a unified, walk-up high performance liquid chromatography/supercritical fluid chromatography/mass spectrometry screening system.

Integration of supercritical fluid/mass spectrometry (SFC/MS) and reversed phase liquid (HPLC/MS) chromatographic screening techniques into a single chromatographic system and utilized in "walk up" mode, enabled us to produce an orthogonal data set for selecting purification conditions for medicinal chemistry compounds. To streamline the overall workflow, we also demonstrate the use of automated batch data processing of individual data files to identify suitable separation conditions without user intervention. We have addressed the chromatographic challenges that hinder the identification of the intended target and thus the selection of ideal purification conditions.

Utilization of DBS within drug discovery: development of a serial microsampling pharmacokinetic study in mice.

Background: Dried blood spots (DBS) are rapidly gaining a foothold in the pharmaceutical industry. However, applications in exploratory drug discovery are limited mainly owing to method development time. The development of a generic DBS assay is presented with its application in serial microsampling from mice.

Influence of age and bladder dysfunction on the contractile properties of isolated human detrusor smooth muscle.

Objective: To test the hypothesis that the in vitro contractile properties of human detrusor smooth muscle are dependent on the age, gender and lower urinary tract pathology of the patient.

Materials And Methods: Contractions were elicited in isolated human detrusor smooth muscle preparations by nerve-mediated electrical field stimulation, agonist application (carbachol, α,β-methylene ATP and high-K solutions) or direct muscle electrical stimulation. Biopsies (n = 227) were obtained from four groups of patients with: stable bladders (control), bladder outlet obstruction (BOO), idiopathic (IDO), or neurogenic (NDO) detrusor overactivity.

Determination of a potent urokinase-type plasminogen activator, UK-356,202, in plasma at pg/mL levels using column-switching HPLC and fluorescence detection.

A rapid, sensitive and selective method using column-switching HPLC with fluorescence detection has been developed for the determination of UK-356,202, a potent urokinase-type plasminogen activator, in human plasma. A structural isomer of UK-356,202 is used as an internal standard. The lower limit of quantification is 20 pg/mL and the method is linear over a 100-fold concentration range.

Late onset dopa-responsive dystonia with tremor, gait freezing and behavioural disturbance and a normal dopamine transporter scan.

A 79-year-old woman presented with dystonic posturing of the right leg while walking and an action tremor of her hands, both of which were levodopa responsive. She subsequently developed gait freezing. However, there was neither generalised bradykinesia nor rigidity.