Explore the vast range of titles available.

Electronic cigarettes (e-cigarettes) are an alternate nicotine delivery system that generate a condensation aerosol to be inhaled by the user. The size of the droplets formed in the aerosol can vary and contributes to drug deposition and ultimate bioavailability in the lung. The growing popularity of e-cigarette products has caused an increase in internet sources promoting the use of drugs other than nicotine (DOTNs) in e-cigarettes. The purpose of this study was to determine the effect of various e-cigarette and e-liquid modifications, such as coil resistance, battery voltage, and glycol and drug formulation, on the aerosol particle size. E-liquids containing 12 mg/mL nicotine prepared in glycol compositions of 100% propylene glycol (PG), 100% vegetable glycerin (VG), or 50:50 PG:VG were aerosolized at three voltages and three coil resistances. Methamphetamine and methadone e-liquids were prepared at 60 mg/mL in 50:50 PG:VG and all e-liquids were aerosolized onto a 10 stage Micro-Orifice Uniform Deposit Impactor. Glycol deposition correlated with drug deposition, and the majority of particles centered between 0.172–0.5 μm in diameter, representing pulmonary deposition. The 100% PG e-liquid produced the largest aerosol particles and the 100% VG and 50:50 PG:VG e-liquids produced ultra-fine particles <0.3 μm. The presence of ultrafine particles indicates that drugs can be aerosolized and reach the pulmonary alveolar regions, highlighting a potential for abuse and risk of overdose with DOTNs aerosolized in an e-cigarette system.

Endogenous serine protease inhibitors are associated with anti-inflammatory and pro-survival signaling mediated via Low-density lipoprotein receptor-related protein 1 (LRP1) signaling. SP16 is a short polypeptide that mimics the LRP1 binding portion of alpha-1 antitrypsin. A pilot phase I, first-in-man, randomized, double blind, placebo-controlled safety study was conducted to evaluate a subcutaneous injection at three dose levels of SP16 (0.0125, 0.05, and 0.2 mg/kg [up to 12 mg]) or matching placebo in 3:1 ratio in healthy individuals. Safety monitoring included vital signs, laboratory examinations (including hematology, coagulation, platelet function, chemistry, myocardial toxicity) and electrocardiography (to measure effect on PR, QRS, and QTc). Treatment with SP16 was not associated with treatment related serious adverse events. SP16 was associated with mild-moderate pain at the time of injection that was significantly higher than placebo on a 0-10 pain scale (6.0+/-1.4 [0.2 mg/kg] versus 1.5+/-2.1 [placebo], P = 0.0088). No differences in vital signs, laboratory examinations and electrocardiography were found in those treated with SP16 versus placebo. A one-time treatment with SP16 for doses up to 0.2 mg/kg or 12 mg was safe in healthy volunteers.

The use of electronic cigarettes (e-cigarettes) is a growing trend in population. E-cigarettes are evolving at a rapid rate with variety of battery powered devices and combustible nicotine refills such as e-liquids. In contrast to conventional cigarettes which are studied well for their toxicity and health effects, long-term clinical data on e-cigarettes are not available yet. Therefore, safety of e-cigarettes is still a major concern. Although the Food and Drug Administration (FDA) has recently started regulating e-cigarette products, no limits on nicotine and other ingredients in such products have been proposed. Considering the regulatory requirements, it is critical that reliable and standardized analytical methods for analyzing nicotine and other ingredients in e-cigarette products such as e-liquids are available. Here, we are reporting a fully validated high-performance liquid chromatography (HPLC) method based on nicotine peak purity for accurately quantifying nicotine in various e-liquids. The method has been validated as per ICH Q2(R1) and USP guidelines. The method is specific, precise, accurate, and linear to analyze nicotine in e-liquids with 1 to >50 mg/mL of nicotine. Additionally, the method has been proven robust and flexible for parameters such as change in flow rate, column oven temperature, and organic phase composition, which proves applicability of the method over wide variety of e-liquids in market.

In electronic cigarette users, nicotine delivery to lungs depends on various factors. One of the important factors is e-liquid nicotine concentration. Nicotine concentration in e-liquids ranges from 0 to >50 mg/mL. Furthermore, nicotine exists in protonated and unprotonated (“free base”) forms. The two forms are believed to affect the nicotine absorption in body. Therefore, in addition to total nicotine concentration, e-liquids should be characterized for their free base nicotine yield. Two approaches are being used for the determination of free base nicotine in e-liquids. The first is applying a dilution to e-liquids followed by two methods: Henderson–Hasselbalch theory application or a Liquid-Liquid Extraction. The second is the without-dilution approach followed by 1H NMR method. Here, we carried out controlled experiments using five e-liquids of different flavors using these two approaches. In the dilution approach, the Henderson–Hasselbalch method was tested using potentiometric titration. The accuracy was found to be >98% for all five e-liquid samples (n = 3). A Liquid-Liquid Extraction was carried out using toluene or hexane as extraction solvent. The Liquid-Liquid Extraction technique was found to be limited by solvent interactions with flavors. Solvent extractions resulted in flavor dependent inaccuracies in free base nicotine determination (5 to 277% of calculated values). The without-dilution approach was carried out using 1H NMR as described by Duell et al. This approach is proposed to offer an independent and alternative scale. None of the methods have established a strong correlation between pre- and postvaporization free base nicotine yield. Here we present comparative results of two approaches using analytical techniques. Such a comparison would be helpful in establishing a standardized method for free base nicotine determination of e-liquids.

Ranibizumab is an FDA-approved drug used to treat wet age-related macular degeneration (AMD), diabetic retinopathy, macular edema, and myopic choroidal neovascularization. Bevacizumab is another drug often used off-label to treat wet AMD. In order to reduce unwanted angiogenesis, ranibizumab and bevacizumab target circulating VEGF-A in the eye. Concentration levels in human vitreous and aqueous humor can be used to provide valuable efficacy information. However, vitreous and aqueous humor’s aqueous environment, and vitreous humor’s viscosity, as well as the stickiness of the analytes can provide bioanalytical challenges. In this manuscript, we describe the development, optimization, and fit-for-purpose validation of an LC-HRMS method designed for intact quantitative bioanalysis of ranibizumab and bevacizumab in human vitreous and aqueous humor following intravitreal administration. In order to fully develop this method, evaluations were conducted to optimize the conditions, including the data processing model (extracted ion chromatograms (XICs) vs deconvolution), carryover mitigation, sample preparation scheme optimization for surrogate and primary matrices, use of internal standard/immunocapture/deglycosylation, and optimization of the extraction and dilution procedure, as well as optimization of the liquid chromatography and mass spectrometry conditions. Once the method was fully optimized, a fit-for-purpose validation was conducted, including matrix parallelism, with a linear calibration range of 10 to 200 µg/mL. The development of this intact quantitative method using LC-HRMS provides a proof-of-concept template for challenging, but valuable new and exciting bioanalytical techniques.

Purpose To develop a unique in vitro aqueous fluid-capacity-limited dissolution system for the kinetic assessment of respirable aerosol drug particles from inhaler products. Methods Aerosol particles of 5 inhaled corticosteroids (ICSs) from 7 inhaler products were collected in the aerodynamic 2.1-3.3 or 4.7-5.8 μm on the filter membranes using the Andersen cascade impactor. Each filter membrane was then placed onto the donor compartment of the Transwell® system, where addition of 0.04ml aqueous fluid initiated aerosol ICS dissolution and permeation across its supporting membrane at 37°C and ∼100% humidity. Results The % profiles of dissolution and permeation were apparent first-order or pseudo-zero-order, reaching varying 1.9-95.0% by 5 h. Their kinetics overall conformed to the ICS aqueous solubility. With increasing aerosol mass, however, the profiles decelerated, attributed to undissolved ICSs left by the limited dissolution fluid capacity. The profiles could be also product-specific, as beclomethasone dipropionate aerosols from QVAR® dissolved faster than those from VANCERIL®, whereas fluticasone propionate aerosols from two different inhaler products exhibited comparable profiles. The 2.1-3.3 μm aerosols dissolved faster than the 4.7-5.8 μm aerosols. Conclusions Aerosol ICS dissolution into the limited aqueous fluid volume differed kinetically due to ICS solubility and aerosol mass, size, formulation and/or generation.

Emerging evidence suggests that classical psychedelics may offer therapeutic potential for opioid use disorder (OUD) by alleviating key hallmarks such as altered reward processing and dependence. However, the mechanisms behind these effects remain unclear. Our data demonstrate that a single administration of the psychedelic psilocybin (PSI) reduces conditioned behavior and withdrawal induced by the opioid oxycodone (OXY) in male mice but not in females, and this effect is mediated via the 5-HT 2A receptor (5-HT 2A R). We show that the sex-specific attenuation of OXY preference is driven by 5-HT 2A R activation in frontal cortex pyramidal neurons projecting to the nucleus accumbens (NAc). Additionally, PSI modulates epigenomic regulation following repeated OXY exposure and induces sex-specific NAc dendritic structural plasticity independently of 5-HT 2A R. Notably, female frontal cortex and NAc show fewer changes at gene enhancer regions in response to PSI, repeated OXY, or combined PSI-OXY treatment compared to males, with the frontal cortex exhibiting more pronounced sex differences than the NAc at the epigenomic level. Together, these results provide new insights into the neural and epigenetic mechanisms of psychedelic-induced plasticity in OUD, while also highlighting sex differences in PSI’s modulation of reward pathways and its therapeutic potential. Here Jaster et al., show a single psilocybin dose produce sex-specific post-acute changes in opioid reward and withdrawal via 5-HT2A receptors in frontal cortex-to–nucleus accumbens circuits, with epigenetic and synaptic changes shaping therapeutic potential.

Poor antiretroviral penetration may contribute to human immunodeficiency virus (HIV) persistence within the brain and to neurocognitive deficits in opiate abusers. To investigate this problem, HIV-1 Tat protein and morphine effects on blood–brain barrier (BBB) permeability and drug brain penetration were explored using a conditional HIV-1 Tat transgenic mouse model. Tat and morphine effects on the leakage of fluorescently labeled dextrans (10-, 40-, and 70-kDa) into the brain were assessed. To evaluate effects on antiretroviral brain penetration, Tat+ and Tat− mice received three antiretroviral drugs (dolutegravir, abacavir, and lamivudine) with or without concurrent morphine exposure. Antiretroviral and morphine brain and plasma concentrations were determined by LC-MS/MS. Morphine exposure, and, to a lesser extent, Tat, significantly increased tracer leakage from the vasculature into the brain. Despite enhanced BBB breakdown evidenced by increased tracer leakiness, morphine exposure led to significantly lower abacavir concentrations within the striatum and significantly less dolutegravir within the hippocampus and striatum (normalized to plasma). P-glycoprotein, an efflux transporter for which these drugs are substrates, expression and function were significantly increased in the brains of morphine-exposed mice compared to mice not exposed to morphine. These findings were consistent with lower antiretroviral concentrations in brain tissues examined. Lamivudine concentrations were unaffected by Tat or morphine exposure. Collectively, our investigations indicate that Tat and morphine differentially alter BBB integrity. Morphine decreased brain concentrations of specific antiretroviral drugs, perhaps via increased expression of the drug efflux transporter, P-glycoprotein.

Studies have evaluated vitamin D3’s therapeutic potential in estrogen-responsive cancers, with conflicting findings. We have shown that the proliferation of breast cancer cells is regulated by 24R,25-dihydroxyvitamin D3 (24R,25(OH)2D3) depending on estrogen receptor alpha 66 (ERα66) expression, suggesting that this could also be the case for estrogen-sensitive laryngeal cancer cells. Accordingly, we examined levels of ERα isoforms in ERα66-positive UM-SCC-12 and ERα66-negative UM-SCC-11A cells and their response to 24R,25(OH)2D3. 24R,25(OH)2D3 stimulated proliferation, increased the expression of metastatic markers, and inhibited apoptosis in UM-SCC-12 cells while having the opposite effect in UM-SCC-11A cells. To evaluate if vitamin metabolites could act via autocrine/paracrine mechanisms, we assessed the expression, protein levels, and activity of vitamin D3 hydroxylases CYP24A1 and CYP27B1. Both cell types expressed both mRNAs; but the levels of the enzymes and their activities were differentially regulated by estrogen. ERα66-negative UM-SCC-11A cells produced more 24,25(OH)2D3 than UM-SCC-12 cells, but comparable levels of 1,25(OH)2D3 when treated with 25(OH)D3 These results suggest that the regulation of vitamin D3 metabolism in laryngeal cancer cells is modulated by ERα66 expression, and support a role for 24R,25(OH)2D3 as an autocrine/paracrine regulator of laryngeal cancer. The local metabolism of 25(OH)D3 should be considered when determining the potential of vitamin D3 in laryngeal cancer.

Statins, 3‐hydroxyl‐3‐methylglutaryl coenzyme A reductase inhibitors, are the first‐line medications prescribed for the prevention and treatment of coronary artery diseases. The efficacy of statins has been attributed not only to their systemic cholesterol‐lowering actions but also to their pleiotropic effects that are unrelated to cholesterol reduction. These pleiotropic effects have been increasingly recognized as essential in statins therapy. This study was designed to investigate the pleiotropic actions of simvastatin, one of the most commonly prescribed statins, on macrophage cholesterol homeostasis with a focus on lysosomal free cholesterol egression. With simultaneous nile red and filipin staining, analysis of confocal/multi‐photon imaging demonstrated that simvastatin markedly attenuated unesterified (free) cholesterol buildup in macrophages loaded with oxidized low‐density lipoprotein but had little effect in reducing the sizes of cholesteryl ester‐containing lipid droplets; the reduction in free cholesterol was mainly attributed to decreases in lysosome‐compartmentalized cholesterol. Functionally, the egression of free cholesterol from lysosomes attenuated pro‐inflammatory cytokine secretion. It was determined that the reduction of lysosomal free cholesterol buildup by simvastatin was due to the up‐regulation of Niemann‐Pick C1 (NPC1), a lysosomal residing cholesterol transporter. Moreover, the enhanced enzymatic production of 7‐hydroxycholesterol by cytochrome P450 7A1 and the subsequent activation of liver X receptor α underscored the up‐regulation of NPC1. These findings reveal a novel pleiotropic effect of simvastatin in affecting lysosomal cholesterol efflux in macrophages and the associated significance in the treatment of atherosclerosis.