Manoj Singh Tomar

Structural and Electrochemical Characterization of Pure LiFePO 4 and Nanocomposite C- LiFePO 4 Cathodes for Lithium Ion Rechargeable Batteries

Pure lithium iron phosphate () and carbon-coated (C-) cathode materials were synthesized for Li-ion batteries. Structural and electrochemical properties of these materials were compared. X-ray diffraction revealed orthorhombic olivine structure. Micro-Raman scattering analysis indicates amorphous carbon, and TEM micrographs show carbon coating on particles. Ex situ Raman spectrum of C- at various stages of charging and discharging showed reversibility upon electrochemical cycling. The cyclic voltammograms of and C- showed only a pair of peaks corresponding to the anodic and cathodic reactions. The first discharge capacities were 63, 43, and 13 mAh/g for C/5, C/3, and C/2, respectively for where as in case of C- that were 163, 144, 118, and 70 mAh/g for C/5, C/3, C/2, and 1C, respectively. The capacity retention of pure was 69% after 25 cycles where as that of C- was around 97% after 50 cycles. These results indicate that the capacity and the rate capability improved significantly upon carbon coating.

A Quantitative Analysis of Memantine in Human Plasma Using Ultra Performance Liquid Chromatography/Tandem Mass Spectrometry

The aim of this study is to compare the single-dose oral bioavailability of memantine hydrochloride 10 mg tablets of Ranbaxy Laboratories Limited, with NAMENDA™ tablets (containing memantine hydrochloride 10 mg) of Forest Pharmaceuticals Inc. in healthy, adult, human subjects under fasting condition. The study was carried out as 2-way crossover design on 8 subjects in fasting and fed conditions. The plasma samples were obtained over a 72 h post dose in each period. Plasma memantine samples were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) with positive ion electro spray ionization using multiple reactions monitoring (MRM). A sensitive, reproducible, accurate and validated LC-MS/MS method with limit of quantification (LOQ) 0.200 ng/mL was used to analyze memantine. Ln transformed AUC0-72 and Cmax were assessed for bioequivalence using 90% confidence interval (CI). 90% confidence intervals for the ratio of test and reference (Ratio of least-squares mean) for ln-transformed AUC0-72 and Cmax were within the regulatory acceptance criteria of 80-125%.

Rapid, Sensitive and Validated Ultra-Performance Liquid Chromatography/Mass Spectrometric Method for the Determination of Fenofibric Acid and its Application to Human Pharmacokinetic Study

The first, rapid and sensitive ultra performance liquid chromatography mass spectrometric method for the determination of fenofibric acid, the active metabolite of fenofibrate, a lipid regulating agent, in human EDTA plasma has been developed and validated using fenofibric d6 acid as internal standard and Waters LC-MS/MS. Negative ions of fenofibric acid and fenofibric d6 acid were detected in multiple reaction-monitoring (MRM) mode. The method was validated over a concentration range of 0.176 μg/mL to 19.837 μg/mL (r ≥ 0.99). It took only 1.5 minute to analyse a sample. Intra- and inter-run precision of fenofibric acid assay at four concentrations ranged from 0.5% to 4.3% with accuracy varied from 93.1 to 108.1% indicating good precision and accuracy. Analytical recoveries of fenofibric acid and internal standard in plasma were less than 90%. This method was successfully applied for evaluation of pharmacokinetics of fenofibric acid after a single oral dose of 145 mg fenofibrate to 10 Indian healthy volunteers

Synthesis, characterization, and electrochemical response of iron oxide nanoparticles for sensing acetaminophen

Magnetite (Fe3O4) and hematite (α-Fe2O3) iron oxide nanoparticles were synthesized using the co-precipitation method via subsequent heat treatment using ferrous chloride (FeCl2.4H2O) as a source of iron. The synthesized powder was annealed at high temperature in an air atmosphere to promote the formation of the hematite (α-Fe2O3) phase. Both oxide phases of iron oxide were characterized using x-ray diffraction, thermogravimetric, and differential scanning calorimetric analysis, and Raman spectroscopy. The phases of as-synthesized nanoparticles were confirmed by XRD and Raman studies. The thermal behavior and weight loss of the initial powdered Fe3O4 to α-Fe2O3 was studied using TG-DSC analysis. In the present case, the Fe3O4 and α-Fe2O3 nanoparticles were used for the electrochemical sensing of acetaminophen (C6H9NO2). The sensing of acetaminophen was performed by Fe3O4 and α-Fe2O3 modified glassy carbon electrode, using a potential controlled cyclic voltammetric technique. The Fe3O4 and α-Fe2O3 nanoparticles exhibited electrocatalytic ability for sensing acetaminophen. Detailed results are included.

A pharmacokinetic drug interaction study of ceftazidime with clavulanic acid in healthy male Indian subjects

Ceftazidime is a third generation cephalosporin with a broad range of activity. Clavulanic acid is a β-lactamase inhibitor. A fixed dose combination, with the wide spectrum of action of ceftazidime and clavulanic acid’s high stability to β-lactamases has been developed by Ranbaxy Laboratories Limited (India). The present study was planned to predict any interaction between ceftazidime and clavulanic acid which could affect the safety and efficacy of the fixed dose combination. The study was an open label, balanced, randomized two-treatment, two-period, two-sequence, crossover, single-dose comparative pharmacokinetic study under fed conditions. A single intravenous injection of the test product containing a fixed dose combination of ceftazidime 2000 mg and potassium clavulanate 200 mg and the reference product containing ceftazidime 2000 mg only, was administered during each period. Serial blood samples were collected until 12 h post-dose in each period. Ceftazidime and clavulanic acid concentration in plasma were determined using two separate LC-MS/MS methods and then pharmacokinetic parameters were evaluated. No significant difference was seen in the mean Tmax, Cmax, AUC0–t, and AUC0–∞ when the drug was administered as ceftazidime alone and in combination with clavulanic acid. The Confidence Intervals for the log transformed parameters Cmax, AUC0–t and AUC0–∞ were within limits of 80–125% of ceftazidime for the test and reference products. The lack of significant difference between the pharmacokinetic parameters for ceftazidime alone and in the presence of clavulanic acid ruled out any significant interaction between ceftazidime and clavulanic acid.

Structural and Electrochemical Characterization of Pure and Nanocomposite C- Cathodes for Lithium Ion Rechargeable Batteries

Pure lithium iron phosphate () and carbon-coated (C-) cathode materials were synthesized for Li-ion batteries. Structural and electrochemical properties of these materials were compared. X-ray diffraction revealed orthorhombic olivine structure. Micro-Raman scattering analysis indicates amorphous carbon, and TEM micrographs show carbon coating on particles. Ex situ Raman spectrum of C- at various stages of charging and discharging showed reversibility upon electrochemical cycling. The cyclic voltammograms of and C- showed only a pair of peaks corresponding to the anodic and cathodic reactions. The first discharge capacities were 63, 43, and 13 mAh/g for C/5, C/3, and C/2, respectively for where as in case of C- that were 163, 144, 118, and 70 mAh/g for C/5, C/3, C/2, and 1C, respectively. The capacity retention of pure was 69% after 25 cycles where as that of C- was around 97% after 50 cycles. These results indicate that the capacity and the rate capability improved significantly upon carbon coating.

Comparison of pharmacokinetics of citalopram in healthy Asian Indian and Mexican volunteers

Randomized, two-way crossover, bioequivalence studies were conducted separately in healthy Mexican and Asian Indian volunteers. One tablet either of test or of reference product was administered after 10 h of overnight fasting. After dosing, serial blood samples were collected for a period of 72 h and 168 h, respectively, for both the studies. Plasma samples were analyzed for citalopram by a validated liquid chromatographic and mass spectrometric method (LC-MS/MS). The pharmacokinetic parameters AUC0–t, AUC0–72, AUC0–∞, Cmax, and Tmax were determined from plasma concentration-time profiles for both the test and reference formulation of citalopram 20 mg tablets, and were compared statistically to evaluate bioequivalence between the two brands of citalopram. In both the studies, the analysis of variance (ANOVA) did not show any significant difference between the test and reference formulations and 90% confidence intervals (CI) were lying within the acceptable range for bioequivalence. The test and reference formulations exhibited comparable pharmacokinetics profiles and were bioequivalent, but high values of both Cmax (~ 23%) and AUC (~ 34%) were observed in Asian Indian healthy volunteers as compared to the Mexican volunteers. This may be due to the poor metabolism of Citalopram in the Asian population. This difference in the results of pharmacokinetic parameters of Asian Indian and Mexican volunteers may be attributed to ethnic factors.

Structural and Electrochemical Characterization of PureLiFePO4and Nanocomposite C-LiFePO4Cathodes for Lithium Ion Rechargeable Batteries

Pure lithium iron phosphate () and carbon-coated (C-) cathode materials were synthesized for Li-ion batteries. Structural and electrochemical properties of these materials were compared. X-ray diffraction revealed orthorhombic olivine structure. Micro-Raman scattering analysis indicates amorphous carbon, and TEM micrographs show carbon coating on particles. Ex situ Raman spectrum of C- at various stages of charging and discharging showed reversibility upon electrochemical cycling. The cyclic voltammograms of and C- showed only a pair of peaks corresponding to the anodic and cathodic reactions. The first discharge capacities were 63, 43, and 13 mAh/g for C/5, C/3, and C/2, respectively for where as in case of C- that were 163, 144, 118, and 70 mAh/g for C/5, C/3, C/2, and 1C, respectively. The capacity retention of pure was 69% after 25 cycles where as that of C- was around 97% after 50 cycles. These results indicate that the capacity and the rate capability improved significantly upon carbon coating.