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The objective of this work was to study the degradation behavior of escitalopram oxalate under different International Conference on Harmonization (ICH)-recommended stress conditions by column liquid chromatography (LC)-UV and LC/mass spectrometry (LC/MS) and to establish a validated stability-indicating LC assay method. Escitalopram oxalate was subjected to stress conditions of hydrolysis, oxidation, photolysis, and thermal decomposition. Extensive degradation was found to occur in alkaline medium. Mild degradation was observed in acidic and oxidative conditions. Escitalopram oxalate was stable to neutral, photolytic, and thermal stress. Successful separation of the drug from degradation products formed under stress conditions was achieved on a PerfectSil-100 ODS-3 column [C18 (5 m, 25 cm 4.6 mm id)] using methanol0.01 M acetate buffer pH 3.8 adjusted with acetic acid (45 + 55) as the mobile phase. The flow rate was 1 mL/min, and the detection wavelength was 239 nm. The method was validated according to ICH guidelines. Major degradation products formed in hydrolysis and oxidative conditions were isolated, and structural elucidation of degradation products was done by LC/MS and infrared spectrometry studies. The major hydrolysis degradation product was confirmed as 1-(3-dimethylaminopropyl)-1-(4-fluoro- phenyl)-1,3dihydroisobenzofuran-5-carboxylic acid, and the major oxidative degradation product was confirmed as 1-{[3-dimethylamino(oxide)- propyl]-1-(4-fluro-phenyl)}-1,3-dihydro-isobenzofuran- 5-carbonitrile.

This paper describes a new, simple, precise, and accurate TLC method for simultaneous quantitation of amlodipine (AML) besylate and valsartan (VAL) as the bulk drug and in tablet dosage forms. Chromatographic separation of the drugs was performed on aluminum plates precoated with silica gel 60 F 254 as the stationary phase and the solvent system consisted of toluene:methanol:acetic acid 7:3:0.1 (v/v/v). Densitometric evaluation of the separated zones was performed at 244 nm. The two drugs were satisfactorily resolved with R F values of 0.41 ± 0.02 and 0.54 ± 0.02 for AML and VAL, respectively. The accuracy and reliability of the method was assessed by evaluation of linearity (100–600 ng spot−1 for AML and 1,600–9,600 ng spot−1 for VAL), precision (intra-day RSD 1.51–1.83% and inter-day RSD 1.24–1.95% for AML, and intra-day RSD 0.14–0.39% and inter-day RSD 0.19–0.52% for VAL), accuracy (98.29 ± 1.16% for AML and 98.72 ± 0.50% for VAL), and specificity, in accordance with ICH guidelines.

Al2O3 passivated CdS sensitized 1D Zr:Fe2O3 nanorod arrays have been synthesized on fluorine-doped tin oxide (FTO) by hydrothermal method and dip coating methods. The photoelectrochemical study of CdS/1D Zr:Fe2O3 photoelectrode exhibits the current density of 4.2 mA.cm-2 at 0 V (vs. Ag/AgCl) which is 2.8 time higher than the bare 1D Zr:Fe2O3. The reduced recombination and the effective transport of photogenerated holes in CdS facilitates the enhancement in photoelectrochemical performance. Furthermore, the photocurrent and stability of the CdS/Zr:Fe2O3 nanorods was significantly enhanced by Al2O3 compared to bare CdS/Zr:Fe2O3 heterojunction due to its ability to act as an effective hole transport as well as photocorrosion protecting layer. The chemical analyses and nanostructural study of the Al2O3 coated CdS/1D Zr:Fe2O3 photoelectrodes confirms the presence of Al2O3 on surface of CdS and 1D Zr:Fe2O3 nanorods embedded in the CdS flakes. These remarkable enhancements in light energy harvesting, improvement in charge transport and stability directly suggest the usefulness of photoelectrodes for solar hydrogen generation. KEYWORDS: Al2O3 passivation; Zr:Fe2O3 nanorod arrays; CdS Sensitizer; Hydrogen generation ACKNOWLEDGMENT This research was supported by the BK21 plus program, the Korean National Research Foundation (Nano-Material Fundamental Technology Development, 2016M3A7B4909370).

Fast charge separation and availability of surface hydroxyl groups are important aspects for photocatalysis. Fast charge separation could be achieved by forming interface between the catalysts and transition metal oxides. In the present work we accomplish charge separation by controllably forming interface between acid treated molten salt rutile TiO2 nanorods and transition metal oxide co-catalysts. FT-IR and XPS (oxygen deconvolution) results confirmed that hydroxyl groups were enhanced on the surface of rutile TiO2 nanorods after acid treatment. Transition metal oxide (MnO, NiO, Co2O3, and CuO) co-catalysts were successfully loaded on the surface of acid treated TiO2 nanorods (ATO-NRs) by conventional wet impregnation method. HR-TEM analysis revealed fine dispersion of metal oxide nanoparticles on the surface of ATO-NRs. The photocatalytic activities of as-prepared (TO-NRs), acid treated (ATO-NRs), metal oxide loaded (MTO-NRs), and both acid treated and metal oxide loaded (MATO-NRs) nanorods were compared based on the rate kinetics and dye degradation efficiency was also determined. Cobalt oxide (1 wt%) loaded on 1.0 M acid treated TiO2 nanorods (Co/ATO-NR), exhibited the higher photocatalytic degradation efficiency of 98.57% within 120 min compared to other photo-catalysts under solar irradiation. The synergistic effect of acid treatment and co-catalyst for improved photocatalytic activity of TO-NRs might be due to fast charge transfer of finely dispersed metal oxides on the OH rich surface of acid treated TiO2 nanorods. Photoelectrochemical analysis demonstrated that the charge transfer process in Co/ATO-NR is significantly higher than the untreated samples. Charge transfer mechanism involved in such co-catalyst loaded photocatalyst was studied in detailed. KEYWORDS: Synergistic effect; co-catalyst; Acid treatment; Transition metal oxides; Dye degradation Acknowledgments This research was supported by the BK21 plus and Basic Science Research Programs (2012R1A6A3A04038530) funded by the Korean National Research Foundation (NRF).

Transition metal oxides (MnO, NiO, Co2O3 and CuO) 1 w % loaded on acid treated TiO2 nanorods were successfully prepared by chemical treatment and wet impregnation method. The catalyst were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), Fourier transform infrared spectroscopy (FT-IR) and UV-visible diffuse reflectance spectroscopy (UV-DRS). FT-IR results confirmed the presence of H2O and OH groups on the surface of acid treated photocatalyst and TEM and XPS results confirmed the fine dispersion of metal and their oxide on TiO2 nanorods. The photocatalytic activity of as-prepared, acid treated, metal oxide loaded and metal oxide loaded on acid treated nanorods were compared and rate constant values were determined from kinetics of the degradation of Orange (II) dye. Cobalt oxide 1w% loaded on 1.0 M acid treated TiO2 nanorods exhibited the higher photocatalytic Orange (II) degradation efficiency 98.57% (within 120 min) than as-prepared and metal loaded acid treated samples under the solar irradiation. The synergistic effect of cobalt oxide 1w% loaded on 1.0 M acid treated TiO2 nanorods over Orange (II) degradation is considered due to fine dispersion of metal oxides on the OH rich surface of acid treated TiO2nanorods. The mechanism of enhanced photocatalytic activity and photoelectrochemical analysis of photocatalyst also studied. Key words: TiO2rutile nanorods; acid treatment; wet impregnation; transition metal oxides, dye degradation; synergistic effect Acknowledgments This research was supported by the BK21 plus and Basic Science Research Programs (2012R1A6A3A04038530) funded by the Korean National Research Foundation (NRF).

CdS sensitized 1D Zr:Fe2O3 nanorod arrays have been synthesized on fluorine-doped tin oxide (FTO) by hydrothermal method. The photoelectrochemical measurement results of CdS/1D Zr:Fe2O3 photoelectrode shows the current density of 4.2 mA.cm-2 at 0 V (vs. Ag/AgCl) which is 2.8 time higher than the bare 1D Zr:Fe2O3. The reduced recombination, and the effective transport of photogenerated holes in CdS facilitates the enhancement in photoelectrochemical performance. Furthermore, the photocurrent and stability of the CdS/Zr:Fe2O3 nanorods was significantly enhanced by Al2O3 layer as compared to bare CdS/Zr:Fe2O3 heterojunction due to its ability to act as an effective hole transport as well as passivation layer. The chemical analyses and nanostructural study of the Al2O3 coated CdS/1D Zr:Fe2O3 photoelectrodes confirms the presence of Al2O3 on surface of CdS and 1D Zr:Fe2O3 nanorods embedded in the CdS flakes. These remarkable enhancements in light energy harvesting, improvement in charge transport and stability directly suggest the usefulness of photoelectrodes for solar hydrogen generation. KEYWORDS: Zr:Fe2O3 nanorod arrays, CdS Sensitizer, Al2O3 passivation layer, Hydrogen generation ACKNOWLEDGMENT: This research was supported by the BK21 plus program, the Korean National Research Foundation (Nano-Material Fundamental Technology Development, 2016M3A7B4909370).

Highly transparent pure and Au doped TiO2 thin films are successfully deposited by using simple chemical spray pyrolysis technique. The effect of Au doping onto the structural and physicochemical properties has been investigated. The PEC study shows that, both short circuit current (Isc) and open circuit voltage (Voc) are (Isc=1.81mA and Voc=890mV) relatively higher at 3at.% Au doping percentage. XRD study shows that the films are nanocrystalline in nature with tetragonal crystal structure. FESEM images show that the film surface covered with a smooth, uniform, compact and rice shaped nanoparticles. The Au doped thin films exhibit indirect band gap, decreases from 3.23 to 3.09eV with increase in Au doping. The chemical composition and valence states of pure and Au doped TiO2 films are studied by using X-ray photoelectron spectroscopy. The photocatalytic degradation effect is 49% higher in case 3at.% Au doped TiO2 than the pure TiO2 thin film photoelectrodes in the degradation of benzoic acid. It is revealed that Au doped TiO2 can be reused for five cycles of experiments without a requirement of post-treatment while the degradation efficiency was retained.

Various doping percentage of Au were successfully introduced into the Fe2O3 photocatalysts via a spray pyrolysis method different. The effect of Au doping on photoelectrochemical, structural, optical and morphological properties of these deposited thin films is studied. The PEC characterization shows that, the photocurrent increases gradually with increasing Au content initially up to 2at.% indicating the maximum values of short circuit current (Isc) and open circuit voltage (Voc) are (Isc=90μA and Voc=220.5mV) and then decreases after exceeding the optimal Au doping content. Therefore, the photocurrent of Au doped Fe2O3 photocatalysts can be adjusted by the Au content. Deposited films are polycrystalline with a rhombohedral crystal structure having (104) preferred orientation. SEM and AFM images show deposited thin films are compact and uniform. The photocatalytic activities of the Fe2O3 and Au:Fe2O3 photocatalyst were evaluated by photoelectrocatalytic degradation of salicylic acid under sunlight irradiation. The results show that the Au:Fe2O3 thin film photocatalyst exhibited about 45% more degradation of pollutants than the pure Fe2O3. Thus, in Au doped Fe2O3 photocatalysts, the interaction between Au and Fe2O3 reduces the recombination of photogenerated charge carriers and improve the photocatalytic activity.

UV, first, second and third derivative spectrophotometric methods have been developed for the determination of ezetimibe in pharmaceutical formulation. The solutions of standard and sample were prepared in methanol. For the first method, UV spectrophotometry, the quantitative determination of the drug was carried at 233 nm and the linearity range was found to be 6-16 mug/ml. For the first, second and third derivative spectrophotometric methods the drug was determined at 259.5 nm, 269 nm and 248 nm with the linearity ranges 4-14 mug/ml, 4-14 mug/ml and 4-16 mug/ml. The calibration graphs constructed at their wavelength of determination were found to be linear for UV and derivative spectrophotometric methods. All the proposed methods have been extensively validated. The described methods can be readily utilized for the analysis of pharmaceutical formulation. There was no significant difference between the performance of the proposed methods regarding the mean values and standard deviations.

The Fe(2)O(3), TiO(2) and TiO(2)/Fe(2)O(3) composite films are deposited using spray pyrolysis method onto glass and FTO coated substrates. The structural, morphological, optical and photocatalytic properties of Fe(2)O(3), TiO(2) and TiO(2)/Fe(2)O(3) thin films are studied. XRD analysis confirms that films are polycrystalline with rhombohedral and tetragonal crystal structures for Fe2O3 and TiO(2) respectively. The photocatalytic activity was tested for the degradation of Rhrodamine B (Rh B) in aqueous medium. The rate constant (-k) was evaluated as a function of the initial concentration of species. Substantial reduction in concentrations of organic species was observed from COD and TOC analysis. Photocatalytic degradation effect is relatively higher in case of the TiO(2)/Fe(2)O(3) than TiO(2) and Fe(2)O(3) thin film photoelectrodes in the degradation of Rh B and 98% removal efficiency of Rh B is obtained after 20min. The photocatalytic experimental results indicate that TiO(2)/α-Fe(2)O(3) photoelectrode is promising material for removing of water pollutants.

Zinc oxide (ZnO) thin films have been successfully deposited onto fluorine doped tin oxide coated glass at substrate temperature of 400 °C and used as electrode in photoelectrocatalytic reactor. The untreated textile effluent was circulated through photoelectrocatalytic reactor under UVA illumination for the decolorization and degradation. Textile effluent was decolorized by 93% within 3h at room temperature with significant reduction in COD (69%). High performance liquid chromatography (HPLC) and Fourier transform infrared spectroscopy (FTIR) analysis of samples before and after decolorization confirmed the degradation of dyes molecules from textile effluent into simpler oxidizable products. Phytotoxicity study revealed reduction in toxic nature of textile effluent after treatment.

A sensitive, simple, selective, precise, and accurate HPTLC method of analysis for paracetamol, diclofenac potassium, and famotidine both as a bulk drug and in tablet formulation was developed and validated. The method used HPTLC aluminum plates precoated with silica gel 60F254 as the stationary phase, and the mobile phase consisted of toluene-acetone-methanol-formic acid (5 + 2 + 2 + 0.01, v/v/v/v). Densitometric evaluation of the separated zones was performed at 274 nm. This system was found to give compact spots for paracetamol (Rf value = 0.62 +/- 0.03), diclofenac potassium (0.75 +/- 0.02), and famotidine (0.17 +/- 0.03). The linear regression analysis data for the calibration plots showed a good linear relationship over the concentration range of 1625-9750 ng/spot for paracetamol, 250-1500 ng/spot for diclofenac potassium, and 100-600 ng/spot for famotidine. The method was validated for precision, robustness, and recovery according to International Conference on Harmonization guidelines. No chromatographic interference from the tablet excipients was found. Statistical analysis showed that the method was repeatable and selective for the simultaneous quantitation of the three drugs in tablet formulation and for routine quality control of raw materials of the drugs.

A sensitive, selective, precise, and stability-indicating thin-layer chromatographic (TLC) method was developed and validated for the determination of tenatoprazole both as a bulk drug and in formulation. The method uses TLC aluminum plates precoated with Silica Gel 60F-254 as the stationary phase and the solvent system toluene-ethyl acetate-methanol (6 + 4 + 1, v/v/v). This system gave compact spots for tenatoprazole (Rf value of 0.34 +/- 0.02). Tenatoprazole was subjected to acid and alkali hydrolysis, oxidation, and photodegradation. The peaks of the degradation products were well-resolved from that of the pure drug and had significantly different Rf values. Densitometric analysis of tenatoprazole was performed in the absorbance mode at 306 nm. The linear regression analysis data for the calibration plots showed a good linear relationship over the concentration range of 100-1500 ng/spot. The mean values of the correlation coefficient, slope, and intercept were 0.9989 +/- 1.42, 10.27 +/- 0.965, and 4894.2 +/- 1.24, respectively. The method was validated for precision, robustness, and recovery. The limit of detection and limit of quantitation were 50 and 100 ng/spot, respectively. Statistical analysis showed that the method is repeatable and selective for estimation of tenatoprazole. Because the method can separate the drug from its degradation products, it can be used to monitor stability.

Highly transparent and preferential c-axis oriented nanocrystalline undoped and Al doped zinc oxide (AZO) thin films have been deposited onto amorphous glass substrate by spray pyrolysis. The XRD studies reveal that AZO with a hexagonal (wurtzite) crystal structure having (002) preferred orientation is formed. The atomic force microscope (AFM) shows uniform surface topography. The optical band gap values of undoped and AZO thin films were changed from 3.34 to 3.35 eV. The band gap energy and photoluminescence are found to depend on the Al doping. Thermoelectric power measurement shows film having n-type in nature. Dielectric constant and loss (tan δ) were found to be frequency dependent. Interparticle interactions in the deposited films are studied by complex impendence spectroscopy.

Thin films of nickel-zinc ferrite with general formula Ni x Zn 1-x Fe 2 O 4 (where x = 0.5, 0.6, 0.7, 0.8, 0.9, 1.0) has been prepared using spray pyrolysis technique onto the glass substrates at optimized substrate temperature of 400 °C. The nickel nitrate, zinc acetate and ferric nitrate were used as precursor materials with double distilled water as solvent. As deposited films are annealed at 600 °C for 2 hrs. The X-ray diffraction (XRD) analysis reveals that the Ni x Zn 1-x Fe 2 O 4 thin films are polycrystalline with spinel cubic structure. The SEM images shows the films are smooth and uniform in nature. To understand the semiconducting behavior the DC resistivity of films was measured using two point probe method. To know the conduction mechanism of ferrites the AC conductivity of thin films was measured. The linear nature of the graph shows the small type of polarons. Frequency dependence of dielectric constant shows dielectric dispersion due to the Maxwell-Wagner type of interfacial polarization. Impedance spectroscopy used to study electrical behavior of grain or grain boundaries.