The applicability of a novel net analyte signal standard addition method (NASSAM) to the resolving of overlapping spectra corresponding to the sulfamethoxazole and trimethoprim was verified by UV-visible spectrophotometry. The results confirmed that the net analyte signal standard additions method with simultaneous addition of both analytes is suitable for the simultaneous determination of sulfamethoxazole and trimethoprim in aqueous media. Moreover, applying the net analyte signal standard additions method revealed that the two drugs could be determined simultaneously with the concentration ratios of sulfamethoxazole to trimethoprim varying from 1:35 to 60:1 in the mixed samples. In addition, the limits of detections were 0.26 and 0.23 μmol L-1for sulfamethoxazole and trimethoprim, respectively. The proposed method has been effectively applied to the simultaneous determination of sulfamethoxazole and trimethoprim in some synthetic, pharmaceutical formulation and biological fluid samples.

A simple and efficient synthesis of 3-(2'-benzothiazolyl)-2,3-dihydro quinazolin-4(1H)- ones has been accomplished by the one-pot condensation of isatoic anhydride, aldehyde and 2-aminobenzothiazole under solvent-free conditions in the presence of Zr(HSO4)4.

A stability-indicating HPLC method was developed and validated for the quantitative determination of fexofenadine in tablet dosage forms. An isocratic seperation was achieved using a Zorbax, Eclipse XBD, C-8 Column having 150 x 4.6 mm i.d., 5 µm particle size column with flow rate of 1.2 ml/min and using UV detector to monitor the eluate at 210 nm. The mobile phase consist of phosphate buffer: acetonitrile: methanol (60:20:20; v/v/v) with pH 3.7 adjusted with o-phosphoric acid. The drug was subjected to oxidation, hydrolysis, photolysis and thermal degradation. Fexofenadine was found to degrate in acidic, basic and oxidation condition. Complete seperation of degraded product was achieved from parent compound. All degradation products in an overall analytical run time of approximately 60 min with the parent compound fexofenadine eluting at approximately 12.1 ±0.9 min. The method was linear over the concentration range of 1-100 µg/ml (r2= 0.9970) with limit of detection and quatification of 0.2 µg/ml and 0.6 µg/ml, respectively. The method has the requisite accuracy, selectivity, sencitivity, precision and robustness to assay fexofenadine in tablets. Degradation products resulting from stress studies did not interfere with the detection of fexofenadine and the assay is thus stability indicating.

A reverse phase HPLC method is described for the determination of Dorzolamide in eye drops. Chromatography was carried on an Inertsil ODS 3V column using Acetonitrile : (0.02M) 1,Octane Sulphonic acid buffer (pH 3.5) (36:64 v/v) on isocratic mode at a flow rate of 1 mL/min with UV detection at 254 nm. The detector response was linear in the concentration range 4-720 µg/mL. The limit of detection and limit of quantification are found to be 0.7041 and 2.3483 µg/mL respectively. The method was validated as per the ICH guidelines. The proposed method is rapid, accurate and precise and can be applied for the routine analysis of dorzolamide in ophthalimic solutions.

The carboxylic acid group of ciprofloxacin was modified and amino mercapto triazole was substituted. The compound was confirmed by physical parameters (solubility, melting point), chromatographic methods (TLC) and consistent with its IR &1HNMR spectra. The synthesized analogue was screened for antibacterial activity against one gram positive & two gram negative species. The compound exhibited good antibacterial effect towards gram negative species when compared to the standard ciprofloxacin. At the same time the analogue was retaining antibacterial activity towards gram positive species when compared to standard ciprofloxacin. The molecular docking studies showed a good correlation between their antibacterial activity and autodock binding free energy.

New Salicylate derivatives of organoheterobimetallic-μ-oxoisopropoxide [Bu2SnO2Ti2(OPri)6] have been synthesized by the thermal condensation ofμ-oxoisopropoxide compound with different salicylates in different molar ratios (1:1-1:4) yielded the compounds of the type [Bu2SnO2Ti2(OPri)6-n(RSal)n] (where n is 1-4 and RSal = Salicylate anion) respectively. Theμ-oxoisopropoxide derivative has been characterized by elemental, liberated isopropanol, and spectral analysis (IR,1H,13C, and119Sn NMR).

Ultrasonic velocity and density measurements were made in two binary liquid mixtures Isopropyl acetate (IPA) and Isobutyl acetate (IBA) with cyclohexanone (CY) as a common component at 303K, at fixed frequency of 2MHz using single crystal variable path interferometer and specific gravity bottle respectively. The experimental data have been used to calculate the acoustic impedance, adiabatic compressibility, inter molecular free length and molar volume. The excess thermodynamic parameters have been evaluated and discussed in the light of molecular interactions.

The present communication deals with the synthesis of a series of fluorinated 10H-phenothiazines. 10H-phenothiazines is prepared by Smiles rearrangement of substituted 2-foramido-2´-nitrodiphenylsulfide. Substituted 2-foramido-2´-nitrodiphenylsulfide were obtained by the reaction of 2-amino-3-fluorobenzenethiol witho-halonitrobenzenes followed by formylation and 1-nitro/1-halo-10H-phenothiazines have been prepared by the reaction of substituted 2-aminobenzenethiols with reactiveo-halonitrobenzene containing a nitro group or halogen atom ato-position to the reactive halogen atom directly yielded 1-nitro/1-halo-10H-phenothiazines in situ. 10H-phenothiazine sulfone derivatives have been synthesized by the oxidation of 10H-phenothiazines by 30% hydrogen peroxide in glacial acetic acid. The structure of the synthesized compounds has been characterized by spectroscopic data and elemental analysis. Antimicrobial studies of the synthesized compounds have also been included.

The inhibition efficiency and synergistic behaviour of 10-4M Atropine methochloride was carried out using mass loss and polarisation methods in the presence of (i) metal ions, Ni2+and Cu2+between 10-2M to 10-6M concentrations, (ii) different concentrations of metal ions and 10-3M I-, 10-3M Cl-and 10-3M Br-solutions and (iii) different metal ions, 10-3M I-and at three different temperatures. The analysis reveals that the inhibition efficiency of Atropine methochloride was maximum at 10-2M in 5 hours of immersion period. Halides decreased the corrosion rate of mild steel in Sulphuric acid. The decrease is maximum with 10-3M I-. As the temperature increased from 298K to 308K, the inhibition efficiency gradually decreased. The inhibitor was found to be effective up to 303K

The adsorption of chromium(VI) on activated carbons prepared from low cost materials has been studied by batch process. The influences of various parameters like contact time, dosage, pH, pHzpc and co-ions were experimentally verified. The adsorption of Cr(VI) is maximum at strongly acidic medium (pH 3). Adsorption is explained using Langmuir and Freundlich isotherms with help of chi-square analysis. Thermodynamic parameters like ΔG°, ΔH° and ΔS° were calculated to understand the nature of adsorption. The surface morphology of the three activated carbons before and after metal sorption was verified using scanning electron microscope (SEM) and X-ray diffraction studies (XRD).