A RAPID RP-HPLC METHOD DEVELOPMENT AND VALIDATION FOR THE QUANTITATIVE ESTIMATION RIBAVIRIN IN TABLETS

Objective: To develop an accurate, precise and linear Reverse Phase High Performance Liquid Chromatography (RP-HPLC) method and validate as per ICH guidelines for the quantitative estimation of Ribavirin (200mg) in tablets.Methods: The optimized method uses a reverse phase column, Enable Make KromasilC18 (250 X 4.6 mm; 5μ), a mobile phase of phosphate buffer (pH 4.2): acetonitrile in the proportion of 85:15 v/v, flow rate of 1.0 ml/min and a detection wavelength of 215 nm using a PDA detector.Results: The developed method resulted in Ribavirin eluting at 2.606 min. Ribavirin exhibited linear in the range 25-150μg/ml. The precision is exemplified by the relative standard deviation of 0.4%. Percentage Mean recovery was found to be in the range of 98â€102, during accuracy studies. The limit of detection (LOD) and limit of quantitiation (LOQ) was found to be 0.24ng/ml and 0.73ng/ml respectively.Conclusion: An accurate, precise and linear RP-HPLC method was developed and validated for the quantitative estimation of Ribavirin in VIRAZIDE (200mg) tablets as per ICH guidelines and hence it can be used for the routine analysis in various pharmaceutical industries.Â

A comparative study of the consistent and simplified finite element analyses of Eigenvalue, problems

Classical displacement method of the finite element analysis of eigenvalue problems requires the use of consistent and conforming elements. However, simpler approaches based on relaxing the condition of consistency of the element descriptions, such as lumped inertia force method and others are also found to yield satisfactory results. In this paper we make a comparative study of the consistent and simplified approaches with reference to four representative problems. In the simplified approach studied in this paper, the contribution of straining modes in the derivation of the mass and geometric stiffness matrices is neglected and this simplifies their derivation substantially. The results indicate that this simplification introduces only small errors in the eigenvalues

Assessment of accuracies of finite eigenvalues

This article does not have an abstract

Study of Electrical and Thermal Behaviour of Li-ion Polymer Cells for Auxiliary Power Supply in Underwater Applications

Lithium  ion  polymer (Li-Po) battery technology is the latest technology for portable use and the most promising technology for exercise torpedoes. These batteries are technologically evolved from Lithium ion batteries. In this paper, extensive experimental studies on Li-Po cells which include studies on electrical characteristics during charge-discharge cycles, discharge at different C rates, self discharge throughout  charge stand, temperature profiles at the cathode and anode during the discharges, etc. are reported and discussed. The extensive electrical characterisation done on these cells indicates the capability of these cells for use as auxiliary power supply in underwater weapon applications.Defence Science Journal, 2012, 62(2), pp.127-131, DOI:http://dx.doi.org/10.14429/dsj.62.99

A CONCEPTUAL MOBILE GIS SYSTEM FOR GLOBAL EMISSION MONITORING

Today information systems play key role in new century, geographical information system (GIS) as a special class of information system. Now we are moving wired to wireless network, that is mobile environment shown in fig2 (any where any time and any thing computing), plays key role in this new century. In this application mobile GIS, which will be a network environment, is proposed, which can perform monitoring of emission levels at a city level or country level or Global level. The concept will be as follows. The analog data of Automated weather monitoring devices (AWMD) will be converted into digital form where by the respective Clint device will transfer data to the server using wireless application protocol (WAP) the hardware and software system need to be integrated where by the mobile GIS components include atmospheric emission data receivers/analyzers WAP clients of GPS enabled system routers are linked to a GIS with relevant software. In the light of Kyoto protocol speedy and accurate determination of emission levels is need of the hour. This is especially required for signatory countries of Kyoto protocol. In this context fixed mobile automated weather stations can be connected to a mobile GIS based data base on a network / web based GIS. This will enable daily/weekly/monthly / yearly monitoring of hazardous parameters from the atmosphere is possible. In this paper the mobile GIS based system its principle of operation hardware and software requirements and the conceptualization are presented. This system is believed to be idealistic for the monitoring and emission quantification

First simultaneous lidar observations of sodium layers and VHF radar observations of E-region field-aligned irregularities at the low-latitude station Gadanki

Simultaneous observations of atmospheric sodium (Na) made by a resonance lidar and E-region field-alignedirregularities (FAI) made by the Indian MST radar, both located at Gadanki (13.5°N, 79.2°E) and horizontal winds acquired by a SKiYMET meteor radar at Trivandrum (8.5°N, 77°E) are used to investigate the relationship among sodium layer, FAI and neutral winds in the mesosphere and lower thermosphere region. The altitudes and descent rates of higher altitude (~ 95 km) Na layer and FAI agree quite well. The descending structures of the higher altitude Na layer and FAI are found to be closely related to the diurnal tidal phase structure in zonal winds observed over Trivandrum. At lower altitudes, the descent rate of FAI is larger than that of Na layer and zonal tidal phase. These observations support the hypothesis that the metallic ion layers are formed by the zonal wind shear associated with tidal winds and subsequently get neutralized to manifest in the form of descending Na layers. The descending FAI echoing layers are manifestation of the instabilities setting in on the ionization layer. In the present observations, the altitudes of occurrence of Na layer and FAI echoes being low, we surmise that it is quite possible that the FAI echoes are due to the descent of already formed irregularities at higher altitudes

A new secosteroid from the gorgonian Subergorgia suberosa Pallas of the Indian Ocean

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Therapeutic implications of recombinant human erythropoietin in anaemic related clinical manifestations

The introduction of recombinant human erythropoietin (RHUEPO) has revolutionised the treatment strategies for patients suffering with anaemia of chronic renal disease and chronic heart failure. Clinical studies and several observational evidences have demonstrated that RHUEPO is also useful in various non-uraemic conditions including haematological and oncological disorders, prematurity, HIV infection and preoperative therapies. The successful treatment of all the anaemic related malfunctions with recombinant human erythropoietin (RHUEPO) has become a standard treatment tool for dialysis patients and as an interesting therapeutic option for several forms of non-renal anaemia. As a conesquence of both, RHUEPO has achieved the highest annual sales worldwide and the potential of it increases its scope in the future prospective also

Spin Pseudo Gap in La2-xSrxCuO4 Studied by Neutron Scattering

Spin excitations of La2-xSrxCuO have been studied using inelastic neutron scattering techniques in the energy range of 2 meV =< w =< 12 meV and the temperature range of 8 K =< T =< 150 K. We observed a signature of a spin pseudo gap in the excitation spectrum above Tc for the slightly overdoped sample with x = 0.18. On heating, the spin pseudo gap gradually collapses between T = 80 K and 150 K. For the x = 0.15 and 0.20, although the visibility of gap-like structure at T ~ Tc is lower compared to the x = 0.18 sample, the broad bump of kai"(w) appears at w ~ 5 meV,close to the spin-gap energy at base temperature, suggests the existence of the spin pseudo gap in the normal state.Comment: revtex, 7 pages, 8 eps figures, PRB (2003) in pres

A combined computational and experimental investigation of the [2Fe–2S] cluster in biotin synthase

Biotin synthase was the first example of what is now regarded as a distinctive enzyme class within the radical S-adenosylmethionine superfamily, the members of which use Fe/S clusters as the sulphur source in radical sulphur insertion reactions. The crystal structure showed that this enzyme contains a [2Fe–2S] cluster with a highly unusual arginine ligand, besides three normal cysteine ligands. However, the crystal structure is at such a low resolution that neither the exact coordination mode nor the role of this exceptional ligand has been elucidated yet, although it has been shown that it is not essential for enzyme activity. We have used quantum refinement of the crystal structure and combined quantum mechanical and molecular mechanical calculations to explore possible coordination modes and their influences on cluster properties. The investigations show that the protonation state of the arginine ligand has little influence on cluster geometry, so even a positively charged guanidinium moiety would be in close proximity to the iron atom. Nevertheless, the crystallised enzyme most probably contains a deprotonated (neutral) arginine coordinating via the NH group. Furthermore, the Fe···Fe distance seems to be independent of the coordination mode and is in perfect agreement with distances in other structurally characterised [2Fe–2S] clusters. The exceptionally large Fe···Fe distance found in the crystal structure could not be reproduced