Mass Balance and ADME Properties of Balcinrenone Following Oral Administration in Combination with Intravenous Microtracer in Healthy Subjects

An absorption, distribution, metabolism, and excretion study was performed to determine the basic pharmacokinetic parameters, mass balance, and metabolite profiles of balcinrenone, a mineralocorticoid receptor modulator, in humans. This open-label, single-center, non-randomized study had a 2-period design. In Period 1, eight healthy male subjects were dosed with a microtracer intravenous infusion of [¹⁴C]balcinrenone shortly after receiving an oral dose of unlabeled balcinrenone in a capsule. Following a 7-day washout, the same group of subjects subsequently received an oral dose of [¹⁴C]balcinrenone as a suspension in Period 2. Clearance and absolute bioavailability of balcinrenone were determined to be 14.2 l/h and 52%, respectively. Renal clearance was determined to be 5.4 l/h (>fu • glomerular filtration rate), indicating elimination via active tubular secretion, which was potentially mediated by P-glycoprotein 1 and/or organic anion transporter 3 according to in vitro transporter data. In total, 94.1% of the oral dose was recovered; 45.2% in the urine and 48.9% in the feces. Balcinrenone was primarily metabolized via oxidation, and in vitro data suggest that cytochrome P450 3A4 was the main enzyme responsible. Intact [¹⁴C]balcinrenone accounted for 55% of drug-related material in the plasma; four metabolites were identified, each representing <6% of the total plasma radioactivity. In conclusion, this 2-period study has determined the basic pharmacokinetic parameters of balcinrenone in humans, including absolute bioavailability and disposition. No metabolites warranted further evaluation on account of their low representation, and any contribution to the pharmacodynamic response or potential drug-drug interactions was deemed negligible. Significance Statement This study provides a detailed understanding of the pharmacokinetics, disposition, and metabolism of balcinrenone following oral and microtracer intravenous administration in humans. In vitro phenotyping and transporter data granted mechanistic insights into the absorption, distribution, metabolism, and excretion properties of balcinrenone. This knowledge will guide future nonclinical and clinical studies evaluating drug-drug interactions, organ dysfunction, and safety of metabolites.

Adherence evaluation of vented chest seals in a swine skin model

OBJECTIVES

Perforation of the chest (open pneumothorax) with and without lung injury can cause air accumulation in the chest, positive intrapleural pressure and lead to tension pneumothorax if untreated. The performance of chest seals to prevent tension physiology depends partially on their ability to adhere to the skin and seal the chest wound. Novel non-occlusive vented chest seals were assessed for their adhesiveness on skin of live swine under normal and extreme environmental conditions to simulate austere battlefield conditions.

METHODS

Chest seals were applied on the back of the swine on skin that was soiled by various environmental contaminants to represent battlefield situations. A peeling (horizontal rim peeling) and detachment and breaching (vertical pulling) techniques were used to quantify the adhesive performance of vented chest seals. Among eight initially selected vented seals, five (Bolin, Russell, Fast breathe, Hyfin and SAM) were further down-selected based on their superior adherence scores at ambient temperatures. The adherence of these seals was then assessed after approximately 17h storage at extreme cold (-19.5°C) and hot (71.5°C) temperatures.

RESULTS

Adherence scores for peeling (above 90%) and detachment scores (less than 25%) were comparable for four vented chest seals when tested at ambient temperature, except for the Bolin seal which had higher breaching. Under extreme storage temperatures, adherence peeling scores were comparable to those at ambient temperatures for four chest seals. Scores were significantly lower for the Bolin seal at extreme temperatures. This seal also had the highest detachment and breaching scores. In contrast, the Russell, Fast breathe, Hyfin and SAM seals showed similar ability to stay air tight without breaching after hot storage.

CONCLUSION

No significant difference was found in skin adherence of the five vented chest seals at ambient temperature and the four seals (Russell, Fast breathe, Hyfin and SAM) maintained superior adherence even after exposure to extreme temperatures compared to the Bolin. To select the most effective product from the 5 selected vented chest seals, further functional evaluation of the valve of these chest seals on a chest wound with the potential for tension in the pneumothorax or hemopneumothorax is warranted.

Antibacterial efficacy testing of a bioelectric wound dressing against clinical wound pathogens

Silver-based wound dressings have been developed for the control of bioburden in wounds. However, the popularity and extensive use of silver-based dressings has been associated with emerging microbial resistances to silver. In this study we examined in vitro antibacterial efficacy of a bioelectric dressing containing silver and zinc against various wound pathogens. Antibiotic-sensitive clinical wound isolates showed a 100% reduction in bacterial growth, except that Enterococcus faecalis isolate was shown to survive with a bacterial log₁₀ reduction rate of less than 10² CFU. We also investigated antibacterial efficacy against the extended spectrum β-lactamase (ESBL) bacteria, multidrug-resistant (MDR) bacteria, and methicillin-resistant Staphylococcus aureus (MRSA). The bioelectric dressing was effective in killing wound pathogens including ESBL, MDR, and MRSA in vitro. Furthermore, based on the primary results against E. faecalis, we carried out extensive studies against several nosocomial Enterococcus species including vancomycin-resistant species. Overall, the vancomycin-sensitive or -resistant Enterococcus species were resistant to this dressing at up to 48 h, except for the vancomycin-resistant Enterococcus raffinosus isolate only showing a 100% bacterial reduction at 48 h, but not at 24 h. The results demonstrated the effective bactericidal activity of a bioelectric dressing against antibiotic-sensitive and MDR strains, but Enterococcus species are bacteriostatic.

Quantitative waveform measures of the electrocardiogram as continuous physiologic feedback during resuscitation with cardiopulmonary bypass

BACKGROUND

There are few if any real-time physiologic measures that currently provide feedback during resuscitation from cardiac arrest. Such measures could be used to guide therapy not simply based on process guidelines but on the physiologic response of the patient from moment to moment. To this end, we applied an existing technology - quantitative waveform measures (QWMs) of the ventricular fibrillation (VF) electrocardiogram (ECG) - as a continuous measure of myocardial response to reperfusion with cardiopulmonary bypass (CPB) after prolonged cardiac arrest.

METHODS

Sixteen domestic, mixed-breed swine were sedated, anesthetized and paralyzed. Mechanical ventilation with room air was provided. Large diameter bypass catheters were placed in the right external jugular vein and right femoral artery for cardiopulmonary bypass (CPB). VF was induced with a 3-s 100mA transthoracic shock and left untreated for 15, 20, 25, or 30min, followed by 10min of centrifugal pump CPB (Bard CPS). Continuous Lead II ECG was recorded with an electronic data acquisition system (Power Lab, ADInstruments). Four QWMs representing 4 signal characteristics of the VF ECG were calculated in 5-s windows throughout the course of untreated VF and resuscitation with CPB.

RESULTS

Four animals were assigned to each VF duration group. QWM recovery was inversely correlated with untreated VF duration, and was drastically reduced above 20min of untreated VF. Return of spontaneous circulation (ROSC) was highly unlikely after 20min of untreated VF.

CONCLUSION

QWMs of the VF ECG provided a real-time metric of myocardial electrophysiologic response to reperfusion with CPB. Resuscitation from greater than 20min of untreated cardiac arrest was unlikely. QWMs may be useful for titrating CPB duration before defibrillation and assessing CPR quality independently of process guidelines.