Simultaneous Spectrophotometric Determination of Valsartan and Ezetimibe in Pharmaceuticals

Purpose: To develop a direct, simple and extraction-free spectrophotometric method for the simultaneous estimation of valsartan and ezetimibe in pharmaceuticals.Methods: A spectrophotometric method for the determination of valsartan and ezetimibe was developed using acidic dyes, namely, bromophenol blue (BPB) and bromocresol green (BCG). The method was based on selective ion-pair formation between valsartan and the acidic dye. The yellow coloured ion-pair induces a bathochromic shift in the spectrum with maximum absorbance at 425 and 428 nm for BPB and BCG, respectively. The developed method was validated as per ICH guidelines.Results: With BPB, the ion-pair formed obeyed Beer`s law in the ranges 5 - 40 and 1 - 50 μg/mL for valsartan and ezetimibe, respectively. The assay data for valsartan and ezetimibe were, 99.39 ± 0.53 and 98.17 ± 0.91 %, respectively, for the commercial formulation, and 99.41 ± 0.48 and 98.16± 0.89 %, respectively, for the developed formulation. The method was validated and the correlation coefficient for valsartan and ezetimibe were 0.995 and 0.999, respectively. Recovery was in the range 99.3 - 100.3 %.Conclusion: The proposed method is reproducible, accurate, robust and suitable for the simultaneous quantitative analysis of the studied drugs in bulk and dosage formulation.Keywords: Valsartan, Ezetimibe, Bromophenol blue, Bromocresol green, Spectrophotometric metho

Stability-Indicating HPLC Method for the Simultaneous Determination of Valsartan and Ezetimibe in Pharmaceuticals

Purpose: To develop a simple, accurate, sensitive, precise and robust reverse-phase HPLC stabilityindicating method for the simultaneous estimation of valsartan and ezetimibe in combined tablet formulation.Methods: A stability indicating method for the simultaneous estimation of valsartan and ezetimibe in combined tablet formulation using a RP-HPLC was developed and validated as per ICH guidelines using a symmetry C18 column with a mobile phase comprising phosphate buffer and acetonitrile (58:42 v/v, pH 3.15) with a flow rate of 0.8 mL/min at 230 nm. Stress degradation studies were performed in acidic, alkaline, oxidation and photolysis conditions to demonstrate the stability-indicating power of the method.Results: The contents of valsartan and ezetimibe were in the range of 99.77 ± 0.10 and 99.30 ± 0.43 % in the marketed formulation, 99.77 ± 0.08 and 99.29 ± 0.38 for the test formulation, respectively. The correlation coefficient for both valsartan and ezetimibe was 0.999 and recovery was in the range of 98 – 102 %. The limit of detection (LOD) was 0.2 and 0.3 μg/mL for valsartan and ezetimibe, respectively, while limit of quantification (LOQ) was 1 μg/mL for both valsartan and ezetimibe, respectively.Conclusion: The proposed method is simple, precise, accurate, reproducible, specific and reproducible used for the quantitative determination of valsartan and ezetimibe in bulk and dosage formulations.Keywords: Valsartan, Ezetimibe, Validation, Stability-indicating, Pharmaceutical

Pentoxifylline Plus Prednisolone versus Pentoxifylline Only for Severe Alcoholic Hepatitis: A Randomized Controlled Clinical Trial

Background: Prednisolone and pentoxifylline (PTX) have been shown to be individually useful in severe alcoholic hepatitis with Maddrey discriminant function (MDF) score .32. Previous report suggests that PTX is probably superior to prednisolone alone. However the efficacy of PTX and prednisolone combination over PTX alone in the management of acute alcoholic hepatitis (MDF score ≥32) is yet unrevealed.Aim: The present study was initiated to find out the efficacy of combined pentoxifylline and prednisolone versus PTX alone in acute alcoholic  hepatitis in respect of short and intermediate term outcomes.Subjects and Methods: A total of 124 patients with severe alcoholic hepatitis (MDF score ≥32) initially were evaluated. 62 patients who fulfilled the inclusion and exclusion criteria were randomized and divided into 2 groups. Group 1 received PTX only, whereas Group 2 received PTX plus Prednisolone. The total duration of follow-up was 12 months. Studentfs t-test, Chi-square test, the Kaplan-Meier methods were used forstatistical analysis. Results: A total of 60 patients, 30 in each group were available for finalanalysis. In Group-1, 6 patients expired at the end of 1 year (5 within 3 months and another after 3 months). In Group 2, 10 patients expired at the end of 1 year (9 within 3 months and another after 3 months). Though survival probability is higher among Group 1 patients but the difference is not statistically significant.Conclusion: The combination of PTX plus Prednisolone yields no additional benefit in terms of mortality and morbidity from that of PTX monotherapy.Keywords: Alcoholic hepatitis, Maddrey discriminant function score,  Pentoxifylline, Prednisolon

Radium ion: A possible candidate for measuring atomic parity violation

Single trapped and laser cooled Radium ion as a possible candidate for measuring the parity violation induced frequency shift has been discussed here. Even though the technique to be used is similar to that proposed by Fortson [1], Radium has its own advantages and disadvantages. The most attractive part of Radium ion as compared to that of Barium ion is its mass which comes along with added complexity of instability as well as other issues which are discussed hereComment: Conference proceedin

Exposure to arsenic in drinking water is associated with increased prevalence of diabetes: a cross-sectional study in the Zimapán and Lagunera regions in Mexico

<p>Abstract</p> <p>Background</p> <p>Human exposures to inorganic arsenic (iAs) have been linked to an increased risk of diabetes mellitus. Recent laboratory studies showed that methylated trivalent metabolites of iAs may play key roles in the diabetogenic effects of iAs. Our study examined associations between chronic exposure to iAs in drinking water, metabolism of iAs, and prevalence of diabetes in arsenicosis-endemic areas of Mexico.</p> <p>Methods</p> <p>We used fasting blood glucose (FBG), fasting plasma insulin (FPI), oral glucose tolerance test (OGTT), glycated hemoglobin (HbA1c), and insulin resistance (HOMA-IR) to characterize diabetic individuals. Arsenic levels in drinking water and urine were determined to estimate exposure to iAs. Urinary concentrations of iAs and its trivalent and pentavalent methylated metabolites were measured to assess iAs metabolism. Associations between diabetes and iAs exposure or urinary metabolites of iAs were estimated by logistic regression with adjustment for age, sex, hypertension and obesity.</p> <p>Results</p> <p>The prevalence of diabetes was positively associated with iAs in drinking water (OR 1.13 per 10 ppb, p < 0.01) and with the concentration of dimethylarsinite (DMAs^III) in urine (OR 1.24 per inter-quartile range, p = 0.05). Notably, FPI and HOMA-IR were negatively associated with iAs exposure (β -2.08 and -1.64, respectively, p < 0.01), suggesting that the mechanisms of iAs-induced diabetes differ from those underlying type-2 diabetes, which is typically characterized by insulin resistance.</p> <p>Conclusions</p> <p>Our study confirms a previously reported, but frequently questioned, association between exposure to iAs and diabetes, and is the first to link the risk of diabetes to the production of one of the most toxic metabolites of iAs, DMAs^III.</p

On the possibility of a terahertz light emitting diode based on a dressed quantum well

We consider theoretically the realization of a tunable terahertz light emitting diode from a quantum well with dressed electrons placed in a highly doped p-n junction. In the considered system the strong resonant dressing field forms dynamic Stark gaps in the valence and conduction bands and the electric field inside the p-n junction makes the QW asymmetric. It is shown that the electrons transiting through the light induced Stark gaps in the conduction band emit photons with energy directly proportional to the dressing field. This scheme is tunable, compact, and shows a fair efficiency.Comment: 6 pages, 5 figure

Ultra-violet radiation is responsible for the differences in global epidemiology of chickenpox and the evolution of varicella-zoster virus as man migrated out of Africa

<p>Abstract</p> <p>Background</p> <p>Of the eight human herpes viruses, varicella-zoster virus, which causes chickenpox and zoster, has a unique epidemiology. Primary infection is much less common in children in the tropics compared with temperate areas. This results in increased adult susceptibility causing outbreaks, for example in health-care workers migrating from tropical to temperate countries. The recent demonstration that there are different genotypes of varicella-zoster virus and their geographic segregation into tropical and temperate areas suggests a distinct, yet previously unconsidered climatic factor may be responsible for both the clinical and molecular epidemiological features of this virus infection.</p> <p>Presentation of the hypothesis</p> <p>Unlike other human herpes viruses, varicella-zoster virus does not require intimate contact for infection to occur indicating that transmission may be interrupted by a geographically restricted climatic factor. The factor with the largest difference between tropical and temperate zones is ultra-violet radiation. This could reduce the infectiousness of chickenpox cases by inactivating virus in vesicles, before or after rupture. This would explain decreased transmissibility in the tropics and why the peak chickenpox incidence in temperate zones occurs during winter and spring, when ultra-violet radiation is at its lowest. The evolution of geographically restricted genotypes is also explained by ultra-violet radiation driving natural selection of different virus genotypes with varying degrees of resistance to inactivation, tropical genotypes being the most resistant. Consequently, temperate viruses should be more sensitive to its effects. This is supported by the observation that temperate genotypes are found in the tropics only in specific circumstances, namely where ultra-violet radiation has either been excluded or significantly reduced in intensity.</p> <p>Testing the Hypothesis</p> <p>The hypothesis is testable by exposing different virus genotypes to ultra-violet radiation and quantifying virus survival by plaque forming units or quantitative mRNA RT-PCR.</p> <p>Implications of the hypothesis</p> <p>The ancestral varicella-zoster virus, most probably a tropical genotype, co-migrated with man as he left Africa approximately 200,000 years ago. For this virus to have lost the selective advantage of resistance to ultra-violet radiation, the hypothesis would predict that the temperate, ultra-violet sensitive virus should have acquired another selective advantage as an evolutionary trade-off. One obvious advantage could be an increased reactivation rate as zoster to set up more rounds of chickenpox transmission. If this were so, the mechanism responsible for resistance to ultra-violet radiation might also be involved in reactivation and latency. This could then provide the first insight into a genetic correlate of the survival strategy of this virus.</p

Multiple publications: The main reason for the retraction of papers in computer science

This paper intends to review the reasons for the retraction over the last decade. The paper particularly aims at reviewing these reasons with reference to computer science field to assist authors in comprehending the style of writing. To do that, a total of thirty-six retracted papers found on the Web of Science within Jan 2007 through July 2017 are explored. Given the retraction notices which are based on ten common reasons, this paper classifies the two main categories, namely random and nonrandom retraction. Retraction due to the duplication of publications scored the highest proportion of all other reasons reviewed

Carbohydrate, phenolic and antioxidant level in relation to chlorophyll a content in oilseed winter rape (Brassica napus L.) inoculated with Leptosphaeria maculans

Syftet med föreliggande studien var att undersöka om sjuksköterskors egna rökvanor påverkar attityden till tobakspreventivt arbete på sjukhuset, både till tobakspreventivt arbete med patienterna och attityden till rökfritt sjukhus. Studien är empirisk och utfördes genom kvalitativa intervjuer med sex sjuksköterskor på en vårdavdelning på ett sjukhus i södra Sverige. Data från intervjuerna analyserades och resulterade i sju olika teman: Preventiva rollen, Kunskap om prevention, Vem skall leda det preventiva arbetet, Rökkontroll, Utbildningsnivå och rökning, Sjuksköterskan, en förebild?, Vem ska hjälpa patienten vid rökstopp på sjukhuset?, Är det någon skillnad mellan icke rökande och rökande vad avser rökpreventionen?. Den preventiva rollen hamnade i fokus och skillnader fanns mellan rökande och icke rökande sjuksköterskor både vad gäller preventivt omvårdnasarbete och kontrollThe aim of the present study is to investigate whether nurses smoking habits influence their attitude to tobacco prevention in hospitals, both in their work with patients and regarding their attitude to hospital smoking bans. The following question was posed: is there a difference between smoking and non-smoking nurses in patient-care activities regarding smoking prevention and control? The study is qualitative, based on qualitative interviews with six nurses at a ward of a hospital in Sweden. Interview data were analyzed and eight themes emerged: the role in prevention work knowledge of prevention who is to lead prevention work smoking control smoking and education levels the nurse as a role model who is to help the patient give up smoking possible differences between nonsmoking and smoking nurses regarding smoking prevention. The role in prevention work turned out to be central. Smoking nurses had greater difficulties in connection with preventive work and control, due to their personal experience of how hard it can be to give up smoking habits

Binding Modes of Peptidomimetics Designed to Inhibit STAT3

STAT3 is a transcription factor that has been found to be constitutively activated in a number of human cancers. Dimerization of STAT3 via its SH2 domain and the subsequent translocation of the dimer to the nucleus leads to transcription of anti-apoptotic genes. Prevention of the dimerization is thus an attractive strategy for inhibiting the activity of STAT3. Phosphotyrosine-based peptidomimetic inhibitors, which mimic pTyr-Xaa-Yaa-Gln motif and have strong to weak binding affinities, have been previously investigated. It is well-known that structures of protein-inhibitor complexes are important for understanding the binding interactions and designing stronger inhibitors. Experimental structures of inhibitors bound to the SH2 domain of STAT3 are, however, unavailable. In this paper we describe a computational study that combined molecular docking and molecular dynamics to model structures of 12 peptidomimetic inhibitors bound to the SH2 domain of STAT3. A detailed analysis of the modeled structures was performed to evaluate the characteristics of the binding interactions. We also estimated the binding affinities of the inhibitors by combining MMPB/GBSA-based energies and entropic cost of binding. The estimated affinities correlate strongly with the experimentally obtained affinities. Modeling results show binding modes that are consistent with limited previous modeling studies on binding interactions involving the SH2 domain and phosphotyrosine(pTyr)-based inhibitors. We also discovered a stable novel binding mode that involves deformation of two loops of the SH2 domain that subsequently bury the C-terminal end of one of the stronger inhibitors. The novel binding mode could prove useful for developing more potent inhibitors aimed at preventing dimerization of cancer target protein STAT3