ABSTRACT Agomelatine is a new melatonergic antidepressant with a unique pharmacological action. A stability indicating RP-HPLC method was developed and validated for the determination of agomelatine in active pharmaceutical ingredient using enable thermo hypersil C18 column (250×4.6mm, 5μm) in isocratic mode. The mobile phase consisted of phosphate buffer: methanol (60:40, v/v) with a flow rate of 1.0 ml/min (PDA detection- 232nm).The Retention time was found to be 3.3 min. Linearity was observed over the concentration range of 25 μg/ml to 75μg/ml and the correlation coefficient R2value was found to be 0.999. The method is accurate and recovery was found to be in the range of 98.91-99.18%. The limit of detection of agomelatine was found to be 2.8μg/ml and limit of quantitation was found to be 9.4μg/ml. Agomelatine was subjected to stress conditions including acidic, alkaline, oxidation, photolysis and thermal degradation. Agomelatine is more sensitive to heat and oxidative degradation. The method was validated according to ICH guidelines.

Keywords: Agomelatine, HPLC method, Validation, Stability-indicating.

ABSTRACT Centrifugal partition chromatography (CPC) is a new and unique method of liquid-liquid chromatography. CPC enables the separation of components with nearly identical partition ratios, and is performed without the aid of a solid support. The method is used for chromatographic reaction in addition to chromatographic separation. Centrifugal partition chromatography is a type of counter current chromatography, which is an automated liquid-liquid extraction process permitting hundreds of automatic successive extractions. A CPC instrument or a CPC column is a series of channels linked in cascade by ducts and aligned in cartridges or disks in a circle around a rotor; setting the rotor in motion submits this assembly to a constant centrifugal field. The originality of CPC is that it uses any biphasic liquid-liquid system as mobile and stationary phases. The United States branch of Sanki contributed greatly to the worldwide acceptance of the technique. Recent works performed in the Netherlands and in France have, by means of visualization of flow-patterns in CPC channels, contributed to a better knowledge of hydrodynamics and mass transfer phenomena. Centrifugal partition chromatography has wide advantages like No column to replace, no silica to recycle, Low solvent consumption, High flow rate for low run time, High performances. Purity > 99%, recovery>90%,No sample losses, No denaturation, no irreversible adsorption of the sample, Huge application fields from petroleum extract to proteins. Hence it is widely employed in the pharmaceutical industry. Keywords: CPC (Centrifugal partition chromatography), Partition Disc, CPC Column, Mono axial rotor, Centrifugal force, Fraction collector.

ABSTRACT In the current trends of the analytical chemistry, miniaturization is one of the fast developing research areas. In this miniaturization of analytical techniques, the microfluidics technology plays a very important role. Microfluidics technology means, it is a device that performs one or several laboratory functions on a single chip of only millimeters to a few square centimeters in size. It deals with the handling. Manipulation and controlling of very small fluid volumes like picoliters. Modern developments in the design and utilization of microfluidics devices for fluid transport have found many applications, ranging from the life sciences industries for pharmaceuticals and biomedicine (drug design, delivery and detection, diagnostic devices) to industrial applications of combinatorial synthesis (such as rapid chemical analysis and high throughput screening).There is great interest today in the possibility that prefabricated, miniaturized laboratories will fill this need. A large number of analytical micro fabricated devices have been developed since the concept μ-TAS was introduced. In pharmaceutical and bio analytical research, micro devices have widely been developed for proteomics, genomics, clinical diagnostics and drug discovery. Keywords: Micro fluidic system, Combinatorial synthesis, Fluid transport.

ABSTRACT This paper reviews the recent developments in bio-analysis sample preparation techniques and chromatographic techniques give an update on basic principles and a comparative discussion on the benefits and limitation of every technique. Any bio-analytical technique includes several steps, all of them being vital in order to attain reliable results. The first step is taking aliquots of samples for the analysis, followed by the extraction procedure and sample clean-up, chromatographic analysis and detection. Conventional sample preparation techniques including solid phase extraction (SPE), liquid-liquid extraction (LLE), protein precipitation (PP) and many modern approaches including molecularly imprinted polymers (MIP), solid phase micro extraction (SPME), liquid-liquid micro extraction (LLME), micro extraction by packed sorbent (MEPS) and plenty of others have additionally been featured as fundamental and significant step of bio-analytical methods. Current trends in fast liquid chromatographic separations involve monolith technology, high temperature liquid chromatography (HTLC) and ultra-high performance liquid chromatography (UHPLC). UHPLC has recently become a wide-spread analytical technique in many laboratories which focus on fast and sensitive bio-analytical assays. The key advantages of UHPLC are the increased speed of analysis, higher separation efficiency and resolution, higher sensitivity and much lower solvent consumption as compared to other analytical approaches. This is all enabled by specially designed instruments and sub-2-microne particle packed analytical columns. Keywords: Bio-analytical, Solid phase extraction (SPE), Liquid liquid extraction (LLE), Protein precipitation (PP), Micro dialysis, Micro extraction, Molecularly imprinted polymer (MIP), Micro extraction in packed syringe (MEPS), Monolith, HILIC, UHPLC.

ABSTRACT A simple, precise, rapid, specific and accurate stability indicating reverse phase high performance liquid chromatography method was developed for simultaneous estimation of Atorvastatin (ATV) and Olmesartan (OLM) in pharmaceutical dosage form. Chromatographic separation was performed onAgilent eclipse XDB C8 (150x4.6mm, 5μ)column, with mobile phase comprising of mixture of buffer (pH3.25, adjusted with ortho phosphoric acid), and methanol in the ratio of 60:40v/v, at the flow rate 0.8 ml/min. The detection was carried out at 287 nm. The retention times of OLM and ATV were found to be 2.47 and 3.77 mins respectively with a run time of 6 mins, theoretical levels for OLM and ATV were 6248 and 4867 respectively, with a resolution of 7.57. As per ICH guidelines the method was validated for linearity, accuracy, precision, limit of detection and limit of quantitation, robustness and ruggedness. Linearity of OLM was found in the range of 120-360 μg/mL and that for ATV was found to be 60-180 μg/mL. The correlation coefficient for OLM and ATV were 1.000 and 0.999 respectively. The LOD values for OLM and ATV were 2.845 and 2.927 μg/mL respectively. The LOQ values for OLM and ATV were and 9.486 and 9.756 μg/mL respectively. This demonstrates that the developed method is simple, precise, rapid, selective, accurate and reproducible for simultaneous estimation of OLM and ATV tablet dosage form. Keywords: Atorvastatin (ATV), Olmesartan(OLM), RP-HPLC, Validation, Forced Degradation Studies.