STABILITY INDICATING RP-HPLC METHOD FOR ESTIMATION OF RABEPRAZOLE SODIUM AND MOSAPRIDE CITRATE IN BULK AND FORMULATION

Objective: Development and validation of reversed phase liquid chromatographic method for the quantitative determination of Rabeprazole sodium and Mosapride citrate in bulk and combined dosage form. Methods: A thermo Inert sil, C18 (250 x 4.6 mm i. d., 5 µ) column with mobile phase containing methanol: buffer (ammonium acetate pH 6.5): acetonitrile in the ratio of (50:20:30 %) was used. The flow rate was 1.0 ml/min, column temperature was 25 °C and effluents were monitored at 245 nm. Results: The retention times of Rabeprazole sodium and Mosapride citrate were 2.951 min and 4.195 min, respectively. Correlation co-efficient for Rabeprazole sodium and Mosapride citrate was found to be 0.9999 and 0.9999, respectively. The proposed method was validated with respect to linearity, accuracy, precision, specificity, and robustness. Recovery of Rabeprazole sodium and Mosapride citrate in formulations was found to be in the range of 97-103 % and 98-102 %, respectively confirms the non-interferences of the excipients in the formulation. Conclusion: The proposed HPLC method was found to be simple, precise, accurate and sensitive for the simultaneous estimation of Rabeprazole sodium and Mosapride citrate in pharmaceutical dosage forms. Due to its simplicity, rapidness and high precision, the method was successfully applied to the estimation of Rabeprazole sodium and Mosapride citrate in combined dosage form

Effect of hydrogen bonding and solvent polarity on the fluorescence quenching and dipole moment of 2-methoxypyridin-3-yl-3-boronic acid

Two photophysical properties namely, fluorescence quenching and dipole moment (both ground state and excited state) of 2-methoxypyridin-3-yl-3-boronic acid (2MPBA) have been investigated in alcohol environment using steady state fluorescence technique at 300 K. In quenching studies, a rare but not unusual observation; negative Stern-Volmer (S-V) deviation has been noticed. It has been explained using the concept of solute’s conformational changes in the ground state due to inter-molecular and intra-molecular hydrogen bonding in alcohol environment. The spectroscopic data has been processed using Lehrer equation and thereby Stern-Volmer constant (KSV) has been evaluated. It has been found to be above 100 for most of the solvents used. The data related to dipole moment has been examined using different solvent polarity functions. Theoretical calculation of dipole moment in the ground state has been done using Gaussian software. The general solute–solvent interactions and hydrogen bond interactions have been found to be operative. An appreciable red shift of about 25 nm in the emission spectra has been identified with the rise in solvent polarity and decrease in molar mass of alcohols. It confirms the π→π* transition as well as the possibility of intra-molecular charge transfer (ICT) character in the emitting singlet state of 2MPBA

Inhibition of endogenous reverse transcription of human and nonhuman primate lentiviruses: Potential for development of lentivirucides

AbstractIn the current study, we extended our previous works on natural endogenous reverse transcription (NERT) and further examined its potential as a virucide molecular target in sexual transmission of primate lentiviruses. HIV-1 and SIV virions were pretreated with select nucleoside (NRTIs) and nonnucleoside RT inhibitors (NNRTIs), either alone or in combination with NERT-stimulating substances. The effects of these antiretrovirals on virion inactivation were analyzed in human T cell lines and primary cell cultures. Pretreatment of HIV-1 virions with physiologic NERT-stimulants and 3′-azido-3′-deoxythymidine 5′-triphosphate (AZT-TP) or nevirapine potently inactivated cell-free HIV-1 virions and resulted in strong inhibition of the viral infectivity. Pretreatment of chimeric SHIV-RT virions with NERT-stimulating cocktail and select antiretrovirals also resulted in virion inactivation and inhibition of viral infectivity in T cell lines. Our findings demonstrate the potential clinical utility of approaches based on inhibiting NERT in sexual transmission of HIV-1, through the development of effective anti-HIV-1 microbicides, such as NRTIs and NNRTIs

Application of Linear Discriminant Analysis in Dimensionality Reduction for Hand Motion Classification

The classification of upper-limb movements based on surface electromyography (EMG) signals is an important issue in the control of assistive devices and rehabilitation systems. Increasing the number of EMG channels and features in order to increase the number of control commands can yield a high dimensional feature vector. To cope with the accuracy and computation problems associated with high dimensionality, it is commonplace to apply a processing step that transforms the data to a space of significantly lower dimensions with only a limited loss of useful information. Linear discriminant analysis (LDA) has been successfully applied as an EMG feature projection method. Recently, a number of extended LDA-based algorithms have been proposed, which are more competitive in terms of both classification accuracy and computational costs/times with classical LDA. This paper presents the findings of a comparative study of classical LDA and five extended LDA methods. From a quantitative comparison based on seven multi-feature sets, three extended LDA-based algorithms, consisting of uncorrelated LDA, orthogonal LDA and orthogonal fuzzy neighborhood discriminant analysis, produce better class separability when compared with a baseline system (without feature projection), principle component analysis (PCA), and classical LDA. Based on a 7-dimension time domain and time-scale feature vectors, these methods achieved respectively 95.2% and 93.2% classification accuracy by using a linear discriminant classifier