Development of stability indicating, validated single dissolution method for simultaneous estimation of clopidogrel bisulfate and rivaroxaban in tablet dosage formulation by RP-HPLC method

A dissolution method was developed for combination of two drugs which are already marketed as an individual product, Clopidogrel Bisulfate Tablets USP 75 mg and another is Rivaroxaban Tablets 10 mg & 20 mg. It was emphasized that both products have several advantages when given as combination therapy. Hence, the preference was given to develop a single dissolution method for the analysis of both the active components. This article presents a single dissolution method to accommodate both drugs. The method uses USP Type II Apparatus (paddles) at 75 rpm in 1000 mL of Acetate buffer (pH 4.5) medium containing 1% Sodium Lauryl Sulfate as surfactant at 37 °C± 0.5°C . This dissolution methodology provides good dissolution profiles for both Clopidogrel Bisulfate and Rivaroxaban and is able to discriminate the changes in composition, manufacturing process and stability for the combination tablets. To quantitate both drugs simultaneously, a rapid isocratic reversed-phase liquid chromatographic method was developed and validated

A validated reverse phase hplc method for the simultaneous estimation of clopidogrel bisulfate and rivaroxaban in pharmaceutical application

A simple, sensitive and precise reverse phase high performance liquid chromatographic method has been developed for the simultaneous estimation of Clopidogrel bisulfate and rivaroxaban in pharmaceutical dosage forms. The combination drug was analyzed on BDS hypersil C18, 250mm × 4.6mm, 5µ, Thermo scientific. Mobile phase consisted of  buffer (0.05M KH2PO4 pH 4.0) : methanol in the ratio of 30:70 v/v delivered at a flow rate of 1.0 ml / min and wavelength of detection at 220 nm. The retention times of Clopidogrel bisulfate and Rivaroxaban were 2.39 min and 4.04 min respectively. The developed method was validated according to ICH guidelines. The proposed method can be used for the determination of these drugs in combined dosage forms

Voltage Profile Improvement of Distribution System via Integration of Distributed Generation Resources

This study attempts to identify the causes and possible solutions for voltage profile issues in the lower land of Nepal, and is specifically focused on Laukahi feeder, a radial distribution system with an approximate length of 65 km and distributed at 11KV system voltage. Currently, the end-users feeding through this feeder are getting extremely poor voltage along with frequent interruptions in the power supply. In this study, a forward/ backward sweep algorithm is used to analyze the load flow of the distribution system, whereas ant colony optimization (ACO) technique is used to identify the best location for the Distributed Generator (DG) penetrations. After completion of this study, it is found that, the branch loss of the feeder can be reduced up to 87.22%, and voltage profile can be improved from 0.828 pu to 0.982 pu by integrating some form of DGs

Chemistry of enediynyl azides: activation through a novel pathway

The spontaneous activation of a nonaromatic enediynyl azide under ambient conditions has been demonstrated. The aromatic enediyne followed the expected cycloaddition with the alkene in the neighbouring arm to form a stable bridged bicyclic enediyne

Assesment of electricity excess in an isolated hybrid energy system: A case study of a Dangiwada village in rural Nepal

The increasing demand of power can be fulfilled through different architectures and electricity supply models by utilizing the available local resources. But most of the isolated energy system suffers from high energy cost and unreliable energy supply. This study identifies different electricity supply models to fulfill the dynamic demand of power in a remote area, which is analyzed in terms of cost of energy and causes for the high cost of energy. Among different factors, the presence of unusable energy (Electricity Excess) produced by the energy system during fulfillment of the demand is found to be major one cause for the high cost of energy. Further, the importance of energy storage system in isolated energy system is discussed. In this case, up to 83.4 % of electricity excess is observed, which can be utilized in different manners to reduce the total energy cost. Electricity excess profile for different energy model, their impacts and possible techniques of the solution with open views are discussed

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Synthesis of 3D porous CeO2/reduced graphene oxide xerogel composite and low level detection of H2O2

composite. The CeO2/rGO xerogel composite electrode displays much enhanced performance for the catalytic reduction of H2O2 than the single component CeO2. The CeO2/rGO modified glassy carbon electrode displayed a wide linear range (60.7 nM–3.0 �M), and low level of detection limit (30.40 nM) for H2O2 and much higher sensitivity than that of CeO2 nanoparticles modified electrode. The sensor fabricated by the xerogel composite was fast, stable, and reliable to the detection of hydrogen peroxide

Simultaneous estimation of pyrantel pamoate, praziquantel & febantel by high performance liquid chromatography using dual wavelength

A sensitive, fast, and stability-indicating gradient reverse-phase liquid chromatography method was developed for quantitative simultaneous estimation of Pyrantel pamoate, Praziquantel and Febantel using reverse phase high performance liquid chromatography by  gradient elusion with dual wavelength at  a specified time interval. All three ingredients were well separated with Phenominax Hypersil C18 (ODS) (4.6 X100mm) 3µm column. The various factors affecting different parameters during method development by HPLC was analyzed and standardized

Theory of anomalous diffusive reaction rates on realistic self-affine fractals

We developed a theoretical method based on limited scale power law form of the interfacial roughness power spectrum and the solution of diffusion equation under the diffusion-limited boundary conditions on rough interfaces. This theoretical method is useful for the analysis of diffusion-limited flux/current to limited scale self-affine random fractal interfaces and is compared with experimentally measured electrochemical current for nano- and micron scales of roughness. The new result explains experimental findings of the temporal scale invariance as well as deviation from this in transition, short, and long time regions. Our result show flux/current transients in terms of three dominant fractal morphological parameters, that is, fractal dimension, lower cutoff length scale of fractality, and topothesy, for the limited length scales of fractality. More broadly, these results are applicable for all time scales and roughness factors

Multifocal Tubercular Dactilytis of Feet with Tubercular Ulcers

Tuberculosis is a common disease in developing countries like India, affecting all age groups. Pulmonary tuberculosis is the most common manifestation of the disease but the disease may affect almost any part of the body. Among cases presenting with skeletal tuberculosis, tuberculosis of the spine, commonly known as Pott's spine, is the most common. Tuberculosis of the short and tubular bones of hands and feet is called tubercular dactilytis. It is a very rare presentation of the disease, usually affecting the small bones of the hand in children younger than 6 years. Tubercular dactilytis, particularly involving the small tubular bones of the foot, is extremely rare