Search Results (14)

Fixed-dose combination therapy is considered a practical approach in the treatment of various diseases, as it can simultaneously target different mechanisms of action that achieve the required therapeutic efficacy through a synergistic effect. A combination of hydrochlorothiazide (HTZ), amlodipine (AMD), and valsartan (VLS) has been created for the treatment of hypertension. Therefore, the aim of this study was to develop an optimized UPLC method for the simultaneous quantification of this combination. A DoE at a level of 32 was used to investigate the effects of column temperature (20, 30, and 40 °C) and formic acid concentration (0.05, 0.15, and 0.25%) on the retention time of each active pharmaceutical ingredient (API), the peak area, and the peak symmetry, as well as the resolution between HTZ-AMD and AMD-VLS peaks. The optimized analytical method was validated and used to extract the three APIs from the marketed product. The optimized analytical condition with a column temperature of 27.86 °C and a formic acid concentration of 0.172% showed good separation of the three APIs in 1.62 ± 0.006, 3.59 ± 0.002, and 3.94 ± 0.002 min for HTZ, AMD, and VST, respectively. The developed method was linear with the LOQ for a HTC, AMD, and VST of 0.028, 0.038, and 0.101 ppm, respectively. Moreover, the developed assay was sustainable and robust, with an RSD % of less than 2%. The application of this method in the extraction of HTZ, AMD, and VST from the Exforge^® marketed product showed good separation with a measurable drug content of 23.5 ± 0.7, 9.68 ± 0.1, and 165.2 ± 5.2 mg compared to the label claims of 25/10/160 for HTZ, AMD, and VST, respectively. Full article

The presence of mutagenic and carcinogenic N-nitrosamine impurities in medicinal products poses a safety risk. While incorporating antioxidants in formulations is a potential mitigation strategy, concerns arise regarding their interference with drug absorption by inhibiting intestinal drug transporters. Our study screened thirty antioxidants for inhibitory effects on key intestinal transporters—OATP2B1, P-gp, and BCRP in HEK-293 cells (OATP2B1) or membrane vesicles (P-gp, BCRP) using ³H-estrone sulfate, ³H-N-methyl quinidine, and ³H-CCK8 as substrates, respectively. The screen identified that butylated hydroxyanisole (BHA) and carnosic acid inhibited all three transporters (OATP2B1, P-gp, and BCRP), while ascorbyl palmitate (AP) inhibited OATP2B1 by more than 50%. BHA had IC₅₀ values of 71 ± 20 µM, 206 ± 14 µM, and 182 ± 49 µM for OATP2B1, BCRP, and P-gp, respectively. AP exhibited IC₅₀ values of 23 ± 10 µM for OATP2B1. The potency of AP and BHA was tested with valsartan, an OATP2B1 substrate, and revealed IC₅₀ values of 26 ± 17 µM and 19 ± 11 µM, respectively, in HEK-293-OATP2B1 cells. Comparing IC₅₀ values of AP and BHA with estimated intestinal concentrations suggests an unlikely inhibition of intestinal transporters at clinical concentrations of drugs formulated with antioxidants. Full article

Antibiotic resistance is a global threat and requires the search for new treatment strategies. Natural antimicrobial peptides (AMPs) have pronounced antibacterial, antiviral, antifungal, and antitumor activity. AMPs’ clinical use is complicated by the high synthesis costs and rapid proteolytic degradation. The search for small molecules, inducers of endogenous AMP expression, could become a new approach. Here, we investigated for the first time the effect of seven small molecules (andrographolide, levofloxacin, azithromycin, montelukast, 4-phenylbutyric acid, rosuvastatin and valsartan) on AMP (beta-defensin-1, hBD-1 and cathelicidin, LL-37) serum levels in rats. In control groups, the level of hBD-1 was 295.0 (292.9–315.4) pg/mL, and for LL-37, it was 223.8 (213.3–233.6) pg/mL. Andrographolide (ANDR) and 4-phenylbutyric acid (4-PHBA) administration significantly enhanced the level of both AMPs. The hBD-1 level was 581.5 (476.3–607.7) pg/mL for ANDR and 436.9 (399.0–531.6) pg/mL for 4-PHBA. The LL-37 level was 415.4 (376.2–453.8) pg/mL for ANDR and 398.9 (355.7–410.1) pg/mL for 4-PHBA. Moreover, we have shown that these compounds reduce mortality in a murine model of sepsis caused by a carbapenem-resistant Klebsiella aerogenes isolate. From our point of view, these small molecules are promising candidates for further study as potent AMP inducers. The data obtained allow the development of new strategies to combat antibiotic resistance and infectious diseases. Full article

Microbes are natural chemical factories and their metabolome comprise diverse arrays of chemicals. The genus Xanthomonas comprises some of the most important plant pathogens causing devastating yield losses globally and previous studies suggested that species in the genus are untapped chemical minefields. In this study, we applied an untargeted metabolomics approach to study the metabolome of a globally spread important xanthomonad, X. perforans. The pathogen is difficult to manage, but recent studies suggest that the small molecule carvacrol was efficient in disease control. Bacterial strains were treated with carvacrol, and samples were taken at time intervals (1 and 6 h). An untreated control was also included. There were five replicates for each sample and samples were prepared for metabolomics profiling using the standard procedure. Metabolomics profiling was carried out using a thermo Q-Exactive orbitrap mass spectrometer with Dionex ultra high-performance liquid chromatography (UHPLC) and an autosampler. Annotation of significant metabolites using the Metabolomics Standards Initiative level 2 identified an array of novel metabolites that were previously not reported in Xanthomonas perforans. These metabolites include methoxybrassinin and cyclobrassinone, which are known metabolites of brassicas; sarmentosin, a metabolite of the Passiflora-heliconiine butterfly system; and monatin, a naturally occurring sweetener found in Sclerochiton ilicifolius. To our knowledge, this is the first report of these metabolites in a microbial system. Other significant metabolites previously identified in non-Xanthomonas systems but reported in this study include maculosin; piperidine; β-carboline alkaloids, such as harman and derivatives; and several important medically relevant metabolites, such as valsartan, metharbital, pirbuterol, and ozagrel. This finding is consistent with convergent evolution found in reported biological systems. Analyses of the effect of carvacrol in time-series and associated pathways suggest that carvacrol has a global effect on the metabolome of X. perforans, showing marked changes in metabolites that are critical in energy biosynthesis and degradation pathways, amino acid pathways, nucleic acid pathways, as well as the newly identified metabolites whose pathways are unknown. This study provides the first insight into the X. perforans metabolome and additionally lays a metabolomics-guided foundation for characterization of novel metabolites and pathways in xanthomonad systems. Full article

Background: The aim of the study was to evaluate the relationship between renin-angiotensin-aldosterone (RAA) system activity and reactivity, and the endothelial function profile in normotensive subjects (N), and in essential hypertensives (H), followed by analysis of the modulatory role of an angiotensin receptor blocker (ARB): valsartan, administered in the management of hypertension. Methods: A total of 101 male subjects were enrolled to the study: 31H and 70N. The nitric-oxide (NO) bioavailability (l-Arginine, asymmetric dimethylarginine (ADMA)), symmetric dimethylarginine (SDMA), endothelial vasodilative function (flow mediated dilation (FMD)), oxidative-stress markers (malonyldialdehyde (MDA), thiol index (GSH/GSSG), nitrotyrozine (N-Tyr)), and pro-inflammatory/angiogenic parameters (sICAM-1, sVCAM-1, PAI-1, sE-selectin, PAI-1, thromboxane -B2) were assessed at baseline, then after intravenous -l-arginine administration, which was repeated after the 4-day acetylsalicylic acid (ASA) administration (75 mg/24 h). In hypertensives, this whole protocol was repeated following 2 weeks of valsartan therapy. Results: No effect of valsartan and ASA on the flow-mediated vasodilation (FMD) and the NO bioavailability in hypertensives was observed. Administration of valsartan increased plasma renin activity (PRA), but without a decrease in the aldosterone levels. ASA treatment minimized the pre-existing differences between the groups, and increased the PRA in the N-subgroup with the highest ARR values. The blood concentrations of proinflammatory sICAM-1, sE-selectin, sVCAM-1, and PAI-1 were higher, whereas the anti-inflammatory 6-keto-PGF1 alpha level was lower in hypertensive subjects. The levels of angiogenic VEGF did not differ between groups. Conclusions: Our study does not confirm the modulative effect of valsartan on endothelial function. Normotensive men showed an increase in FMD after l-arginine administration, possibly indicating baseline impairment of the NO synthesis. Full article

Many nitrosamines are potent carcinogens, with more than 30 listed under California’s Proposition 65. Recently, nitrosamine contamination of commonly used drugs for treatment of hypertension, heartburn, and type 2 diabetes has prompted numerous Food and Drug Administration (FDA) recalls in the US. These contaminants include the carcinogens NDMA (N-nitrosodimethylamine) and NDEA (N-nitrosodiethylamine) and the animal tumorigen NMBA (N-nitroso-N-methyl-4-aminobutyric acid). NMBA and NDEA are metabolically and/or structurally related to NDMA, an N-nitrosomethyl-n-alkylamine (NMA), and 12 other carcinogenic NMAs. These nitrosamines exhibit common genotoxic and tumorigenic activities, with shared target tumor sites amongst chemicals and within a given laboratory animal species. We use the drug valsartan as a case study to estimate the additional cancer risks associated with NDMA and NDEA contamination, based on nitrosamine levels reported by the US FDA, cancer potencies developed by California’s Proposition 65 program and the US Environmental Protection Agency (EPA), and specific exposure scenarios. These estimates suggest that nitrosamine contamination in drugs that are used long-term can increase cancer risks and pose a serious concern to public health. Full article

Senior residences are health-care facilities that are socially-accepted for the assistance of elderly people. Since the elderly account for the foremost pharmaceutical-consuming age-group, senior residences become a hot-spot for pharmaceuticals discharge to the sewage grid. The objectives of the present study were to identify the bioactive pharmaceuticals in sewage waters from senior residences and to propose an on-site monitoring strategy for their control. In this study, we have studied the presence of 43 pharmaceuticals highly consumed by the elderly population in six senior residences located in Spain, France and Portugal. Wastewater was sampled directly from the water-chest in each residence during different times of the day throughout one week. Main compounds detected at the high µg L⁻¹ level were analgesic and antipyretic drugs such as acetylsalicylic acid, paracetamol, ibuprofen; antibiotics such as amoxicillin and sulfamethoxazole; compounds for the treatment of neuropathies as gabapentin, trazodone and valsartan; pharmaceuticals for the treatment of diabetes (vildagliptin) and anticancer drugs. The daily loads discharged were estimated and their fate was evaluated. The final objective of this study is to highlight the need to implement at-source waste water treatment procedures in senior residences, which have been identified as a point source pollution of pharmaceuticals. Full article

Confocal laser scanning microscopy (CSLM) is a powerful microscopic tool that gives valuable morphological and functional information within cells and tissues. CLSM is non-invasive, with high-contrast scanning, a simple and fast sample preparation procedure as well as easy operation. This paper aimed to study the intracellular uptake of polymeric nanoparticles loaded with cardiovascular drugs using confocal laser scanning microscopy. Polymeric nanoparticles were prepared via nanoprecipitation method using poly(lactide-co-glycolide) (PLGA) as a biodegradable polymeric matrix and Pluronic F127 as a stabilizer. A mixture of two cardiovascular drugs—valsartan (an angiotensin II receptor antagonist drug) and amlodipine besylate (a calcium channel blocker)—was loaded in polymeric nanoparticles. The prepared polymeric nanoparticles had sizes lower than 300 nm and narrow dispersity. The cellular uptake of polymeric nanoparticles was investigated by incubating adherent mouse embryo fibroblasts (NIH 3T3) with a suspension of nanoparticles (stained previously with phthalocyanine) at three different time points. Targeted cell compartments were labeled with two fluorophores: Rhodamine B (membrane stain) and Hoechst (nucleic acid stain). Live cell imaging was performed using a confocal microscope Zeiss LSM710 with Zeiss PALM microdissection system. The intracellular uptake of polymeric nanoparticles was revealed by confocal laser scanning microscopy for each incubation time. The results suggest a possible mechanism of endocytosis and clearly a vesicular-based accumulation of the nanoparticles in the cytoplasmatic compartments. Full article

Water reclamation through the use of soil aquifer treatment (SAT) is a sustainable water management technique with high potential for application in many regions worldwide. However, the fate of contaminants of emerging concern (CECs) during the infiltration of treated wastewater during SAT is still a matter of research. This study investigates the removal capacity of 27 CECs during SAT by means of infiltration experiments into a 6 m soil column. Additionally, the influence of the hydraulic operation of SAT systems on the removal of CECs is investigated by changing the wetting and drying cycle lengths. Sixteen out of 27 CECs are efficiently removed during SAT under various operational modes, e.g., bezafibrate, diclofenac and valsartan. For six substances (4-methylbenzotriazole, amidotrizoic acid, benzotriazole, candesartan, hydrochlorothiazide and sulfamethoxazole), removal increased with longer drying times. Removal of amidotrizoic acid and benzotriazole increased by 85% when the drying cycle was changed from 100 to 444 min. For candesartan and hydrochlorothiazide, removal improved by 35%, and for 4-methylbenzotriazole and sulfamethoxazole, by 57% and 39%, respectively. Thus, enhanced aeration of the vadose soil zone through prolonged drying times can be a suitable technique to increase the removal of CECs during SAT. Full article

The process of bank filtration acts as a barrier against many anthropogenic micropollutants, such as pharmaceuticals and industrial products, leading to a substantial improvement of groundwater quality. The performance of this barrier is, however, affected by seasonal influences and subject to significant temporal changes, which have already been described in the literature. Much less is known about spatial differences when considering one field site. In order to investigate this issue, two undisturbed cores from a well-investigated bank filtration field site were sampled and operated in the course of a column study. The ultimate aim was the identification and quantification of heterogeneities with regard to the biodegradation of 14 wastewater derived micropollutants, amongst others acesulfame, gabapentin, metoprolol, oxypurinol, candesartan, and olmesartan. While six of the compounds entirely persisted, eight compounds were prone to degradation. For those compounds that were subject to degradation, degradation rate constants ranged between 0.2 day⁻¹ (gabapentin) and 31 day⁻¹ (valsartan acid). Further, the rate constants consistently diverged between the distinct cores. In case of the gabapentin metabolite gabapentin-lactam, observed removal rate constants differed by a factor of six between the cores. Experimental data were compared to values calculated according to two structure based prediction models. Full article

Granular activated carbon (GAC) adsorbers for drinking water treatment were operated for approx. 14 months and the breakthrough of dissolved organic carbon (DOC) and trace organic chemicals (TOrCs) was monitored. Effluent concentration profiles of gabapentin and valsartan acid increase already at throughputs of <10,000 BV. The corresponding breakthrough curves flatten out without reaching the influent concentration level. This strongly indicates biological degradation of these substances in the GAC adsorbers under aerobic conditions, contributing to a more efficient use of GAC. The observed biodegradation in pilot GAC adsorbers also confirms recent reports of biodegradation of gabapentin and valsartan acid during managed aquifer recharge. Oxypurinol is comparatively well adsorbed and no breakthrough was observed during the experimental period. Adsorption capacity and breakthrough characteristics of oxypurinol appear very similar to carbamazepine. Breakthrough of GAC adsorbers operated with drinking water was compared to those of groundwater-fed adsorbers. The results show, that it is generally advisable to use previously aerated influents for GAC fixed-bed adsorbers because this can substantially improve biological removal of otherwise poorly adsorbable compounds and ensure full GAC accessibility for adsorbates by avoiding the undesirable formation of inorganic precipitates on adsorption sites. Full article

Managed aquifer recharge (MAR) systems are an efficient barrier for many contaminants. The biotransformation of trace organic chemicals (TOrCs) strongly depends on the redox conditions as well as on the dissolved organic carbon availability. Oxic and oligotrophic conditions are favored for enhanced TOrCs removal which is obtained by combining two filtration systems with an intermediate aeration step. In this study, four parallel laboratory-scale soil column experiments using different intermittent aeration techniques were selected to further optimize TOrCs transformation during MAR: no aeration, aeration with air, pure oxygen and ozone. Rapid oxygen consumption, nitrate reduction and dissolution of manganese confirmed anoxic conditions within the first filtration step, mimicking traditional bank filtration. Aeration with air led to suboxic conditions, whereas oxidation by pure oxygen and ozone led to fully oxic conditions throughout the second system. The sequential system resulted in an equal or better transformation of most TOrCs compared to the single step bank filtration system. Despite the fast oxygen consumption, acesulfame, iopromide, iomeprol and valsartan were degraded within the first infiltration step. The compounds benzotriazole, diclofenac, 4-Formylaminoantipyrine, gabapentin, metoprolol, valsartan acid and venlafaxine revealed a significantly enhanced removal in the systems with intermittent oxidation compared to the conventional treatment without aeration. Further improvement of benzotriazole and gabapentin removal by using pure oxygen confirmed potential oxygen limitation in the second column after aeration with air. Ozonation resulted in an enhanced removal of persistent compounds (i.e., carbamazepine, candesartan, olmesartan) and further increased the attenuation of gabapentin, methylbenzotriazole, benzotriazole, and venlafaxine. Diatrizoic acid revealed little degradation in an ozone–MAR hybrid system. Full article

Attenuation of micro-contaminants is a very complex field in environmental science and evidence suggests that biodegradation rates of micro-contaminants in the aqueous environment depend on the water matrix. The focus of the study presented here is the systematic comparison of biotransformation rates of caffeine, carbamazepine, metoprolol, paracetamol and valsartan in river water microcosms spiked with different proportions of treated effluent (0%, 0.1%, 1%, and 10%). Biotransformation was identified as the dominating attenuation process by the evolution of biotransformation products such as atenolol acid and valsartan acid. Significantly decreasing biotransformation rates of metoprolol were observed at treated effluent proportions ≥0.1% whereas significantly increasing biotransformation rates of caffeine and valsartan were observed in the presence of 10% treated effluent. Potential reasons for the observations are discussed and the addition of adapted microorganisms via the treated effluent was suggested as the most probable reason. The impact of additional phosphorus on the biodegradation rates was tested and the experiments revealed that phosphorus-limitation was not responsible. Full article

A rapid high-performance liquid chromatographic (HPLC) method using a monolithic column has been developed for determination of valsartan in human plasma. The assay is based on protein precipitation using acetonitrile and fluorescence detection. The assay enables the measurement of valsartan for therapeutic drug monitoring with a minimum quantification limit of 20 ngml^-1. The method involves simple, one-step extraction procedure and analytical recovery was nearly complete. The separation was carried out in reversed-phase conditions using a Chromolith Performance (RP-18e, 100×4.6 mm) column with an isocratic mobile phase consisting of 0.01 M disodium hydrogen phosphate buffer-acetonitrile (60:40 v/v) adjusted to pH 3.5 with diluted phosphoric acid. The excitation and emission wavelengths were set at 230 and 295 nm, respectively. The calibration curve was linear over the concentration range 20-2000 ngml^-1. The coefficients of variation for inter-day and intra-day assay were found to be less than 6%. The assay was applied for the analysis of blood samples from a pharmacokinetic study. Full article