Simultaneous Determination of Active Clinical Components of Teicoplanin and Ramoplanin in Environmental Water by LC-MS/MS Coupled With Cascade Elution

A simple, sensitive, and simultaneous method was established and validated for the active clinical components of teicoplanin and ramoplanin in environmental water by LC-MS/MS coupled with cascade elution. Moreover, a cascade elution method, which was rapid, solvent-less, and high-extraction efficient was successfully proposed to realize the extraction and purification of seven targets in one step. Under optimized conditions, the method showed excellent linearity with the correlation coefficient (R2) ≥0.998 in the range of 1.0–100.0 ng L−1. Low matrix effects and good recoveries which ranged from 86 to 114% were reached with RSDs lower than 3.0% for most targets. The limits of detection and limit of quantification were 0.1–1.3 and 0.3–4.0 ng L−1, respectively. This method was successfully applied for the determination of teicoplanin and ramoplanin in water samples from the Pearl River and the South China Sea. TA2-2,3 was quantified in only one sample with the concentration of 8.0 ng L−1.

Automated Parallel Pattern Search Optimisation of Microfluidic Geometry for Extracellular Vesicle Liquid Biopsies

Microfluidic liquid biopsies using affinity-based capture of extracellular vesicles (EVs) have demonstrated great potential for providing rapid disease diagnosis and monitoring. However, little effort has been devoted to optimising the geometry of the microfluidic channels for maximum EV capture due to the inherent challenges of physically testing many geometric designs. To address this, we developed an automated parallel pattern search (PPS) optimiser by combining a Python optimiser, COMSOL Multiphysics, and high performance computing. This unique approach was applied to a triangular micropillar array geometry by parameterising repeating unit cells, making several assumptions, and optimising for maximum particle capture efficiency. We successfully optimised the triangular pillar arrays and surprisingly found that simply maximising the total number of pillars and effective surface area did not result in maximum EV capture, as devices with slightly larger pillars and more spacing between pillars allowed contact with slower moving EVs that followed the pillar contours more closely. We then experimentally validated this finding using bioreactor-produced EVs in the best and worst channel designs that were functionalised with an antibody against CD63. Captured EVs were quantified using a fluorescent plate reader, followed by an established elution method and nanoparticle tracking analysis. These results demonstrate the power of automated microfluidic geometry optimisations for EV liquid biopsies and will support further development of this rapidly growing field.

Detection of SARS-CoV-2 in the sewerage system in Tunisia: a promising tool to confront COVID-19 pandemic

Aim: The current study undertaken in Tunisia examines the use of wastewaters to monitor SARS-CoV-2 circulation. Materials & methods: Viral genetic materials collected in wastewaters during two different periods (September–October 2020 and February–April 2021) were concentrated using the adsorption-elution method. SARS-CoV-2 genes were researched by real-time PCR. Results: During the first period of the study, viral RNA was detected in 61.11% of the analyzed samples collected from Monastir city with a rate of 88.88% for raw wastewaters and 33.33% for treated wastewaters. Then, during the second period of the study, the quantitative analysis of wastewaters collected from seven governorates showed the presence of viral RNA among around 25% of them with variable RNA loads. The increased amounts of viral RNA detected in wastewaters were accompanied by an increase in the number of COVID-19 patients in Tunisia. Conclusion: Our results emphasize the importance of sewage survey in SARS-CoV-2 tracking.

Inter-laboratory comparison of water solubility methods applied to difficult-to-test substances

Water solubility is perhaps the single most important physical–chemical property determining the environmental fate and effects of organic compounds. Its determination is particularly challenging for compounds with extremely low solubility, frequently referred to as “difficult-to-test” substances and having solubility’s generally less than 0.1 mg/L. The existing regulatory water solubility test for these compounds is the column elution method. Its applicability, however, is limited, to non-volatile solid or crystalline hydrophobic organic compounds. There currently exists no test guideline for measuring the water solubility of very hydrophobic liquid, and potentially volatile, difficult-to-test compounds. This paper describes a “slow-stir” water solubility methodology along with results of a ring trial across five laboratories evaluating the method’s performance. The slow-stir method was applied to n-hexylcyclohexane, a volatile, liquid hydrophobic hydrocarbon. In order to benchmark the inter-laboratory variability associated with the proposed slow-stir method, the five laboratories separately determined the solubility of dodecahydrotriphenylene, a hydrophobic solid compound using the existing column elution guideline. Results across the participating laboratories indicated comparable reproducibility with relative standard deviations (RSD) of 20% or less reported for each test compound – solubility method pair. The inter-laboratory RSD was 16% for n-hexylcyclohexane (mean 14 µg/L, n = 5) using the slow-stir method. For dodecahydrotriphenylene, the inter-laboratory RSD was 20% (mean 2.6 µg/L, n = 4) using the existing column elution method. This study outlines approaches that should be followed and the experimental parameters that have been deemed important for an expanded ring trial of the slow-stir water solubility method.

Reverse Phase High Performance Liquid Chromatographic Method for Separation and Estimation of impurities present in Pharmaceutical Formulation of Empaglifozin

Empaglifozin is a Sodium-glucose co-transporter-2 inhibitors work by inhibiting SGLT2, to prevent reabsorption of glucose and facilitate its excretion in urine. Impurities in pharmaceuticals which are unwanted chemicals that remain with the active pharmaceutical ingredients (APIs), or develop during stability testing, or develop during formulation or upon aging of both API and formulation. A simple and very sensitive method developed for estimation of impurities present in Empaglifozin formulation by Reverse Phase High Performance Liquid Chromatographic method. Method is capable to detect impurities in very low level (1µg/mL). Chromatographic separation of six different impurities was achieved on Inertsil ODS-2 (250 x 4.6) mm, 3µm column using gradient elution method at 30°C column temperature and the detection was carried at 230nm at a flow rate of 1.0 mL/min. The method was validated as per ICH Q2(R1) guideline along with stress studies.

Identifikasi Golongan Darah O dengan Metode Absorpsi Elusi pada Sampel Darah Kering yang Terdapat pada substrat Kain Jeans dalam Waktu dan Lingkungan Berbeda

This research aims to determine the time limit needed and the environmental conditions that provide the highest success rate in identifying dried blood samples on the fabric of stretch denim, ramie denim, black coated denim, and dry denim jeans using the elution absorption method. Also, to evaluate the effect of the fabric fabric, environmental condition, time, and interactions regarding the success rate of blood group identification. The study was conducted using 3 replications for each type of jeans fabric, which was carried out by exposing blood to a jeans fabric, leaving it in an indoor and outdoor environment for up to 336 hours (14 days), then continued by making a red blood cell suspension for comparison, and examining blood groups using the absorption-elution method. From the results obtained, it is known that the blood exposed in the jeans fabric that being placed indoor for up to 336 hours (14 days) can still be identified and has a success percentage rate of up to 100%. Meanwhile, the blood exposed on the jeans fabric that was placed outdoor could no longer be identified after 264 hours (11 days). Based on the result of this study, it can be concluded that the exposure time of 366 hours (14 days) for the indoor environment can still be identified properly, while the exposure time of 264 hours (11 days) for dry blood samples in the outdoor environment can no longer be identified. The indoor environment gives a better percentage of success than the outdoor environment in identifying blood types from dry blood samples. The best types of substrates that can store blood at an exposure time of up to 336 hours (14 days) are dry denim, black coated denim, and stretch denim.

High salinity enhances the adsorption of 17α-ethinyl estradiol by polyethersulfone membrane: isotherm modelling and molecular simulation

The increasing occurrence of steroidal hormone micropollutant in the aquatic environment and their associated consequences have caused serious environmental concerns globally. Adsorptive removal of hormonal pollutants using polymeric membranes has been suggested but information on their performance in various environmental conditions is lacking. In this study, we examined the effect of salinity on the performance of polyethersulfone (PES) membrane to remove synthetic hormone 17α-ethinyl estradiol (EE2) from water. Our results show that an increase of salinity from 0 to 3% results in higher retention of EE2 onto PES membrane from 79.3 to 98.7%. The experimental results fit the Freundlich isotherm model better as compared to the Langmuir model. The Freundlich parameters n and Kf yielded the highest values at 3% salinity. The molecular simulation results suggest that a high salinity increases the binding energy between EE2 and PES membranes, promoting the PES-EE2 interaction through π–π interaction, hydrogen bonding and hydrophobic interaction. This study provides valuable information for improving design of specialised treatment facilities (in farming, pharmaceutical industries, etc.) to allow better removal of EE2 and other low-polar organic contaminants from water via a membrane-based sorption-elution method, and we recommend the inclusion of salinity as a factor in modelling the adsorption capacity of membranes to prevent the oversaturation of membrane and minimise the release of contaminants into the environment.

Determination of Ketotifen Fumarate in Syrup Dosage Form by High Performance Liquid Chromatography

The goal of the current study was to establish and authenticate an isocratic reverse-stage High-Performance Liquid Chromatography (HPLC) method for quantifying ketotifen fumarate (KF) in pharmaceutical liquid dosage compositions. Easy, quick, accurate, exact, and accurate reverse-stage high-performance liquid chromatography was advanced for the simultaneous assessment of ketotifen fumarate in the liquid syrup dosage type. The HPLC system using isocratic elution method with reverse-phase Inertsil ODS-(250 mm × 4.6 mm, 3 μm) column was detected by ultraviolet absorbance at 297 nm with no interference from widely using excipients, the mobile phase (A) is a mixture of triethylamine and water (175 μl in 500 ml of water), and the mobile phase (B) is a mixture of triethylamine and methanol (175 μl in 500 ml of methanol) at a flow rate of 1.5 mL/min (mobile phase A 40 %:mobile phase B 60%) at column temperature using 40 ° C, the retention time for ketotifen fumarate was 6.4±0.5 min. The concentration curves were linear in the range of 10.0 to 35.0 μg / ml (R2 = 0.9999). The developed method was tested for the specificity, precision, linearity, precision, reliability, robustness, and consistency of the solution. The regeneration of ketotifen fumarate in formulations was found to be 99.75 %, 99.91 %, and 100.05 % respectively. The percent RSD for percent recovery was found to be 0.21 and 0.17 and 0.10 for ketotifen fumarate. In the conclusion, the suggested technique was successfully used for the quantitative determination of ketotifen fumarate in formulations.

Monitoring of rotavirus in treated wastewater in Tehran with a monthly interval, in 2017–2018

Rotaviruses are among the major causes of viral acute gastroenteritis in newborns and children younger than 5 years worldwide. The ability of rotaviruses to remain infectious in harsh environments as well as in the wastewater treatment process makes them one of the most prevalent enteric viruses. The current study aimed to determine the presence of rotavirus genomes and to analyze them phylogenetically in secondary treated wastewater (TW) samples. In total, 13 TW samples were collected from September 2017 to August 2018. Viral concentration was carried out using the absorption-elution method, and after RNA extraction and cDNA synthesis, real-time and conventional polymerase chain reaction (PCR) were performed. A phylogenetic tree was drawn using Maximum Likelihood and Tamura 3-parameter using MEGA v.6 software. Rotavirus genomes were detected in 7/13 (53.8%) and 3/13 (23.07%) samples using reverse transcription (RT)-PCR and conventional PCR, respectively. Accordingly, phylogenetic analysis revealed G4P[8], G9P[4], and G9P[8] genotypes among the samples. The presence of rotavirus in secondary TW samples discharged into surface water emphasizes the importance of monitoring and assessing viral contamination in the water sources used for agricultural and recreational purposes.