ABSTRACT A simple, accurate, economical and reproducible HPLC method for simultaneous estimation of two component drug mixture of Gabapentin and Methylcobalamin (MCB) in combined tablet form have been developed. The detection was performed at 271 nm. The retention time of Gabapentin and Methylcobalamin was found to be 2.5 min and 3.08 min respectively. Linearity was observed in concentration range of 600-1800mcg/ml of Gabapentin and 1-3mcg/ml of Methylcobalamin. The reverse phase chromatographic method used C18 column and 0.1% Orthophosporic acid:acetonitrile in ratio of 55:45 as mobile phase. Results of analysis were validated statistically and by recovery studies. The method was validated according to the ICH guidelines with respect to specificity, linearity, accuracy, precision, and robustness.

Keywords: Gabapentin, Methylcobalamin, HPLC, Validation, Reverse Phase.

ABSTRACT A sensitive, selective and precise high performance liquid chromatographic method has been developed and validated for the simultaneous determination of Rupatidine fumarate and Montelukast sodium in tablet dosage form. The method employed like C18 column, Symmetry C18 (4.6 x 250mm, 5m, Make: Waters) as the stationary phase while Phosphate buffer (pH 3.6), Methanol, Acetonitrile in proportion 30:65:5 v/v respectively. was used as mobile phase. The Retention time of Rupatadine fumarate and Montelukast sodium were observed to be 2.395 and 3.339 minutes, respectively. The flow rate was found to be 1ml/min and effluents were monitored at 230 nm. The linear regression analysis data for the calibration plots showed a good linear relationship for both Rupatadine fumarate and Montelukast sodium and over a concentration range of 10-50 μg/ml. with correlation co-efficient of 0.9989 for Rupatadine fumarate and 0.9999 for Montelukast sodium The LOQ was found to be 4.52 and 3.67μg/ml respectively for Rupatadine fumarate and Montelukast sodium. The method was validated as per ICH guideline and it was found to be accurate, precise and robust. Marketed formulation was analyzed successfully.

Keywords: Rupatadine fumarate, Montelukast sodium, HPLC, Validation etc.

ABSTRACT Capillary electrophoresis (CE) is a separation technique in which the analytes are separated on the basis of differences in their charge-to-size ratios. This makes CE especially suitable for the analysis of molecules with abroad range of sizes, charge and hydrophobicity, as proteins and peptides. Another attractive feature of CE is its ability to handle minute sample amounts, with nano-litre injection volumes, which makes it ideal for applications when the sample volumes are limited, as often is the case in analysis of body fluids, single cells and other small volume analysis of biofluids. Mass spectrometry (MS), is today one of the most advanced detection techniques. It yields maximum accurate information in short time, consuming minimal amounts of sample. MS provides robustness and reproducibility of analysis as well as high throughput possibilities via automatic data acquisition. When combined with ionization techniques like inductively coupled plasma (ICP), electro spray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI), MS allows simultaneous analysis of proteins and peptides with high resolution. However, in order to reach ultimate mass sensitivity a separation step prior to MS detection is often needed. The possibility of combining the properties of MS with a fast and high-efficiency separation provided by CE to meet the analytical challenges, that the complexity of biological samples represents, has been recognized for about two decades. Keywords: Capillary electrophoresis, ICP, Coupling.

ABSTRACT Supercritical Fluid Chromatography (SFC) is a form of normal phase chromatography, first used in 1962.SFC typically utilizes carbon dioxide as the mobile phase; therefore the entire chromatographic flow path must be pressurized. Because the supercritical phase represents a state in which liquid and gas properties converge, supercritical fluid chromatography is sometimes called \"convergence chromatography.\" Supercritical fluid chromatography is one of the most important column chromatography methods after gas chromatography (GC) and high-performance liquid chromatography (HPLC). Supercritical fluids combine useful properties of gas and liquid phases. The characteristic properties of a supercritical fluid are density, diffusivity and viscosity.SFC, the sample is carried through a separating column by a supercritical fluid where the mixture is divided into unique bands based on the amount of interaction between the individual analytes and the stationary phase in the column. As these bands leave the column, their identities and quantities are determined by a detector SFC is a hybrid of gas and liquid chromatography because when the mobile phase is below its critical temperature and above its critical pressure, it acts as a liquid, so the technique is liquid chromatography (LC) and when the mobile phase is above its critical temperature and below its critical pressure, The instrumentation that is required for supercritical fluid chromatography is versatile because of its multi-detector compatibility.SFC has been applied to wide variety of materials including natural products, drugs, foods, pesticides, herbicides, surfactants, polymers and polymer additives, fossils fuels, petroleum, explosives and propellants. Keywords: Critical pressure, Critical temperature, Diffusivity, Supercritical fluid.

ABSTRACT

A simple, precise, rapid, specific and accurate reverse phase high performance liquid chromatography method was developed for simultaneous estimation of Metronidazole and diloxanide furoate in pharmaceutical dosage form. Chromatographic separation was performed on Inertsil ODS 3V, 4.6x250mm, 5μm column, with mobile phase comprising of mixture of buffer (pH 5.5, adjusted with phosphate buffer), acetonitrile and methanol in the ratio of 30:20:50 v/v, at the flow rate 1 ml/min. The detection was carried out at 241 nm. The retention times of Metronidazole and diloxanide furoate were found to be 2.2 and 3.7 mins respectively with a run time of 6 mins, theoretical levels for Metronidazole and diloxanide furoate were 3351 and 5094 respectively, with a resolution of 8.422. As per ICH guidelines the method was validated for linearity, accuracy, precision, limit of detection and limit of quantitation, robustness and ruggedness. Linearity of Metronidazole was found in range of 60-140 µg/mL and that for Diloxanide furoate was found to be 75-175 µg/mL. The correlation coefficient for Metronidazole and diloxanide furoate was 0.99 and 0.99 respectively. The LOD values for Metronidazole and diloxanide furoate were 6.89 and 3.92 µg/mL respectively. The LOQ values for Metronidazole and diloxanide furoate were and 20.87 and 11.88 µg/mL respectively. This demonstrates that the developed method is simple, precise, rapid, selective, accurate and reproducible for simultaneous estimation of Metronidazole and diloxanide furoate tablet dosage form.

Keywords: Metronidazole, Diloxanide furoate, RP-HPLC, Validation.