VALIDATED REVERSE PHASE HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD FOR THE SIMULTANEOUS DETERMINATION OF ARTEMETHER AND LUMEFANTRINE IN FIXED COMBINED DOSAGE FORM

ABSTRACTObjective: The present aim is to develop simple, precise, and accurate reverse phase high performance liquid chromatographic method (RP-HPLC) forthe simultaneous assay of artemether and lumefantrine in fixed combined dosage form.Methods: The chromatographic study was carried out on Hypersil C18 column (250×4.6 mm, 5 μ) with mobile phase containing a mixture of KH2PO4buffer (pH-3.5) and acetonitrile in the ratio of 45:55% v/v at a flow rate of 1.0 ml/minute with ultraviolet detection at 218 nm in ambient columntemperature.Results: Using the optimized chromatographic conditions artemether and lumefantrine eluted with retention times of 2.207 and 3.733 minutes,respectively. The method was validated according to ICH guidelines with good reproducibility and linear responses, y=60.813.x+629.53 (r²=0.9982)for artemether and y=88.3108.x+2370.2 (r²=0.9912). The % relative standard deviations of intra-day precision was ranged 0.378% and 1.26% forartemether and 0.459% and 1.15% for lumefantrine, respectively. The percentage recoveries were ranged from 99.96% to 100.02% for artemetherand 99.96-99.97% for lumefantrine, respectively.Conclusions: The developed RP-HPLC method was validated as per ICH guidelines and was found to be best suitable for pharmacokinetic studies ofthese mentioned drugs.Keywords: Artemether, Lumefantrine, ICH guidelines

Performance Comparison between Nonidentical Segmented Exponential Concave and Nonidentical Segmented Exponential Convex Serrated CATRs

This paper presented a theoretical and numerical assessment for nonidentical segmented exponential- (NISE-) convex and NISE-concave serrated plane CATRs by changing number of serrations. The investigation was based on diffraction theory and, more specifically, on the diffraction formulation of Fresnel. The compact antenna test range (CATR) provides uniform illumination within the Fresnel region to the test antenna. Application of serrated edges has been shown to be a good method to control diffraction at the edges of the reflectors. In this paper, the Fresnel fields of NISE-convex and NISE-concave serrated CATRs are analyzed using physical optics (PO) technique. The PO analysis is applied in this paper for plane reflector serrated CATR only. The same analysis is applied to any type of reflector. In this paper, lens-based reflector is not considered. It is observed that NISE-concave serrated CATR gives less ripple and enhanced quiet zone width than NISE-convex

A review on study of Electrokinetic stabilization of expansive soil

Needless to elaborate the harmful effects of the Expansive soil on the light-weight structures, as it is a very common problem faced by the Structural and Geotechnical engineers all over the world. In INDIA, the site having BlackCotton soil force the local engineers to think differently in order to find a way which can improve the ground condition very efficiently. One solution, which is not used worldwide, is the Electrokinetic Treatment which uses the principle of Electroosmosis, Electromigration and Electrocementation, and has been proved the best for fine grained soil. Till now, inadequate studies have been done to prove its efficiency in using it for the expansive soil. Apparently, there may be some reasons why the researchers don't consider this technique useful in such soils. This paper includes the whole and sole of this treatment reckoned from the past studies and its scope in implementation with Expansive soils. Experimental study, both in field and laboratory, followed by its analysis using available software packages, is required to decide the factors of this treatment influencing expansive soil

A NEW STABILITY-INDICATING RP-HPLC-PDA METHOD FOR SIMULTANEOUS ESTIMATION OF TRIPLICATE MIXTURE OF RAMIPRIL, ATORVASTATIN AND CLOPIDOGREL IN TABLET DOSAGE FORM

Objective: To develop a novel, accurate, precise and linear reverse phase high performance liquid chromatographic (RP-HPLC) method for simultaneous quantitative estimation of ramipril, atorvastatin and clopidogrel in Atamra-CV tablet and validate as per international conference on harmonization (ICH) guidelines and to perform the force degradation studies using the developed method.Methods: In the present work, the good chromatographic separation was achieved isocratically using a shim-pack HPLC Kromasil 150 mm x 4.6 mm, 5 m. m. And mobile phase consisting of 0.05 M potassium dihydrogen orthophosphate pH 3 adjusted with orthophosphoric acid and acetonitrile in the ratio (52:48), at flow rate 1 ml/min and column temperature (30 °C). The effluents obtained were monitored at 210 nm with the UV-visible detector.Results: The retention time of ramipril, atorvastatin and clopidogrel was found to be 2.893 min, 5.012 min and 6.102 min respectively. The linearity of ramipril, atorvastatin and clopidogrel was found in the range of 25-150 % and the correlation coefficient for ramipril, atorvastatin and clopidogrel were>0.999. The high recovery values (98%-101%) indicate a satisfactory accuracy. The low percent relative standard deviation (% RSD) values in the precision study reveals that the method is precise. The three-drug samples were subjected to stress conditions of acidic and alkaline hydrolysis, oxidation, photolysis and thermal degradation. The proposed method proved to be stability-indicating by resolution of the analytes from their forced-degradation products.Conclusion: The developed method is novel, simple, precise, rapid, accurate and reproducible for simultaneous estimation of ramipril, atorvastatin and clopidogrel tablet dosage form. Hence the proposed method may find practical applications as a quality-control tool in the simultaneous analysis of the three drugs in combined dosage forms in quality-control laboratories. The proposed method was made use of photodiode array (PDA) as a tool for peak identification and purity confirmation

EXPERIMENTAL AND THEORETICAL DETERMINATION OF STRUCTURAL, VIBRATIONAL, MOLECULAR, ELECTRONIC, NLO, NBO, AND THERMODYNAMIC CHARACTERISTICS OF PENTABROMOPHENOL AND PENTAFLUROPHENOL#.

Fourier Transform Raman (3500-100 \wn) and Fourier Transform infrared spectra (4000-400 \wn) were measured for Pentabromophenol (PBP) and Pentaflurophenol (PFP). UV-Visible (200-400 nm) spectrum, along with 1H and 13C NMR spectra were also recorded, for PBP. Torsional potentials, optimized structure parameters, barrier height to internal rotation, harmonic vibrational frequencies, general valance force field, potential energy distribution (PED), along with infrared and Raman intensities were evaluated, for PBP and PFP. DFT was used in conjunction with B3LYP functional with 6-311++G(d,p) basis set, for the computations. Scaling process was employed to get a better fit between the measured and computed frequencies. The rms error between them was 9.7 and 7.0 \wn, for PBP and PFP, respectively. Unambiguous vibrational assignments were arrived at by using PED and eigenvectors. In order to understand the nature of intermolecular hydrogen bond in these molecules geometry optimization was made for dimers of PBP and PFP. Further, using Gauge Independent Atomic orbital (GIAO) approach 1H and 13C NMR chemical shifts were evaluated and compared with corresponding experimentally measured shifts for PBP. In the same way, Time-dependent Density Functional Theory (TD-DFT) was used to simulate UV-Visible spectrum of PBP and compared with its experimental spectrum. HOMO and LUMO energies along with associated electronic parameters were generated. In order to find reactive sites in PBP and PFP molecular electrostatic surface potential (MESP) diagrams were drawn. The values of dipole moment, polarizability and hyperpolarizability of these molecules were computed to determine their NLO behavior. To understand the stability of the molecules (PBP and PFP) caused by charge delocalization, natural bond orbital (NBO) analysis was made for both PBP and PFP. Thermodynamic parameters were also evaluated for both the molecules. \\ Key words: Pentabromophenol, Pentaflurophenol, Vibrational spectra, Intermolecular hydrogen bond, DFT, Hyperpolarizability \# A part of this work appeared in J. Mol. Struct. 1180 (2019) 665-675 \

Optimization of machining characteristics during helical milling of AISI D2 steel considering chip geometry

Helical milling is one of the high-performance and high-quality hole manufacturing activities with strong prospects for the automotive and aerospace industries. Literature suggests chip geometry plays a significant role in optimizing machining operations. In the present study, a mechanistic approach is used to estimate the chip geometry, cutting force and power/energy consumption concerning the tool rotation angle. Experiments are conducted at different levels of spindle rotational speed, cutter orbital speed and axial depth of cuts using 8 and 10 mm diameter mill cutters. Experimental results for cutting speed in X, Y and Z directions are measured. A hybrid approach, which combines the Taguchi method and Graph theory and matrix approach (GTMA) technique is used and optimized process parameters. The highest aggregate utility process parameters are met by 2000 rpm spindle speed, 50 rpm orbital speed and 0.2 mm axial cutting depth during helical milling of AISI D2 steel. FEM simulation is used for predicting the chip thickness, cutting forces and power consumption and also validated the optimization

Geometrical inversion in the acids derived from the coumarins. Part V. The behaviour of Psoralic and Isopsoralic acids

The stable trans acids, Psoralic and Isopsoralic acids, have been prepared from Psoralen and Isopsoralen. With concentrated sulphuric acid they undergo complex changes whereas in the presence of sunlight and aqueous mercuric chloride they yield the original pyrones. Though Isopsoralic acid undergoes ring closure more easily the difference is not great

Chemical examination of Erythrina indica

From the seeds of Erythrina indica a fixed oil and a water-soluble alkaloid have been isolated. The properties of the oil have been compared with those of the oil of the Formosan variety and found to differ in the degree of unsaturation. The alkaloid has been identified as hypaphorine. The bark contains, besides a large amount of mineral matter and resin, the same base which is also present in the leaves to a smaller extent