Synthesis and Characterization of Low Valent Metalloporphyrins

Metalloporphyrins and metalloporphinones have been seen in a number of enzymes and involved in nitrogen metabolism, photosynthesis, and methanogenesis. The reduction of metalloporphyrins and metalloporphinones are achievable, but the site of reduction in either, the metal center or porphyrin core is still debatable. This prompted us to investigate the position of reduction in order to generate low valent metalloporphyrins and porphinones. The reduced porphyrins were characterized by spectroscopic and X-ray crystallographic methods. Previous work in our laboratory has generated low valent metalloporphyrins and porphinones by electrochemical reduction. In this work cobalt, manganese, and iron low valent metalloporphyrins were generated via chemical reduction and results were characterized by UV-visible, infrared spectroscopy, and X-ray crystallographic techniques

Can services lead the Indian economy?

Growth of services in the economy of India is viewed with concern and wonder; concern that services may not provide employment opportunities in an economy with a large number of semi- skilled and unskilled workers, wonder that services account for nearly 60$ of the GNP in a developing economy. This paper outlines the factors that have promoted the growth of services, analyses the structure of the services sector and argues that services can lead the economy contrary to popular opinion

On an unusually dense phytoplankton bloom around Minicoy Island (Arabian Sea), and its effect on the local tuna fisheries

The fishing season in this area for the tunas chiefly Katsuwonis pelamis (L.) by surface 'chumming' and angling during the months of February, March and April 1965, was fairly good. However, early in May 1965 the tuna catches suddenly fell off to nil

X-ray Structure and Properties of the Ferrous Octaethylporphyrin Nitroxyl Complex

The preparation and characterization of the iron octaethylporphyrin nitroxyl ion, [Fe(OEP)(NO)−], is reported. The complex was synthesized by the one-electron reduction of Fe(OEP)(NO) using anthracenide as the reducing agent. The compound was isolated as the potassium (2.2.2)cryptand salt. The anion was characterized using X-ray analysis with visible and infrared spectroscopy. The spectral features of the iron nitroxyl complex were consistent with previous literature reports. The important structural changes upon reduction were a significant decrease in the Fe–N–O bond angle from 142° to 127° and an increase in the N–O bond length from that in the starting nitrosyl moiety. The porphyrin ring became significantly less planar upon reduction, but the displacement of the iron atom from the 24-atom plane was essentially unchanged. In spite of the attempt to encapsulate the potassium ion with the (2.2.2)cryptand, significant interaction between K+ and the oxygen of the nitroxyl were observed, indicating a contact ion pair in the crystal structure. Comparison between the experimental structure and the DFT-calculated parameters were reported. The results are consistent with the Fe–N–O moiety being the site of the reduction, with little evidence for the reduction of the iron itself or the porphyrin ring. The proton NMR spectrum was also obtained, and the chemical shifts were significantly different from other S = 0 metalloporphyrin complexes. These shifts, though, were consistent with the DFT calculations

NGOs in India-Uniqueness and Critical Success Factors, Results of an Fgd

In the last few decades, in India, NGOs have grown to play an important role in providing various services to the society. The increase in the number of NGOs and the range of activities of these NGOs, has called for an understanding on the uniqueness, management practices and the factors contributing to their success. The need not only comes from the organisations themselves but also from the various stakeholders of these NGOs. Research in this sector has thrown light on the diversity of NGOs and the distinctive sectoral characteristics. This paper explores the understanding of NGOs, features that bring uniqueness in these NGOs and the critical success factors. Focus group discussion and a qualitative research method have been used to bring out the factors. Based on the factors revealed by the FGD, a model of critical success factors has been developed

THE ROLE OF NEEDLE IN FORMULATION OF pH SENSITIVE SWELLABLE MICROBEADS PREPARED WITH HYDROPHILIC POLYMERS FOR ATORVASTATIN AND THEIR CHARACTERIZATION STUDIES

Objective: The aim of the study was to develop and characterize mucoadhesive microbeads for oral sustained release of atorvastatin by using hydrophilic polymers and application of different process variables in designing of pH sensitive swellable microbeads.Methods: Microbeads were prepared by ionic gelation method. The compatibility studies of atorvastatin with polymers were investigated by differential scanning calorimeter and fourier transform infrared spectroscopy studies. In this work process variable like optimization of curing agents and their quantity, effect of rpm, and their influence in drug entrapment were studied. Prepared beads were characterized for particle size, swelling index, erosion studies and drug release studies.Results: Mixture of alginate and carbopol 934 P at 3.3 % w/v shows sustained release and good mucoadhesive capacity. Furthermore, drug loading and swelling increased with the use of a combination of polymers. On basis of in vitro release studies and swelling studies, it was observed that sodium alginate coated with carbopol 934 P showed sustained release of 84.5 % at end of 10 h in 6.8 phosphate buffer. The optimised batch followed peppas and higuchi release mechanism and releasing the drug by non-fickian transport.Conclusion: The alginate beads with a combination of carbopol 934P showed a sustain release pattern. The release rate and swelling of atorvastatin beads could be adjusted by adding other hydrophilic polymers or by optimising curing agents, curing time and their volume. The zero order of drug release was confirmed for all the batches. The in vitro data was better fit to Higuchi's diffusion model and diffusion rate limited

PROCESS AND PARAMETERS AFFECTING DRUG RELEASE PERFORMANCE OF PREPARED CROSS-LINKED ALGINATE HYDROGEL BEADS FOR EZETIMIBE

Objective: The objective of this study was to formulate an oral sustained release delivery system of ezetimibe mucoadhesive beads by ionic gelation technique based on sodium alginate used as a hydrophilic carrier in combination with carbopol 934P which acts as a rate modifier.Methods: Microbeads of ezetimibe were prepared using an easy method of ionotropic gelation by little modification while in addition of drug. The prepared beads were characterised for mean particle size, entrapment efficiency, swelling capacity, and in vitro release. They were also subjected to various studies such as Fourier Transform Infrared Spectrophotometer (FTIR) Spectroscopy for drug polymer reaction, Scanning Electron Microscopy for surface morphology, and Differential Scanning Calorimetric Analysis to determine the physical state of the drug in the beads.Results: The microspheres of ezetimibe were formulated successfully. The addition of drug concentration gives higher drug loading and higher conc. of Alcl+3 yields small diameter beads and lower drug entrapment. Analysis of the release profiles showed that the data corresponds to zero order release and the diffusion-controlled mechanism as suggested by Higuchi concept.Conclusion: It can be concluded that beads produced by the sequential method had higher drug entrapment. Beads produced by simultaneous yields larger beads in diameter. The concept was cleared that drug release was dependent upon the quantity of polymer and increase in conc. of. aluminium chloride retarded the drug release in the sequential method. Prepared beads enhance the dissolution of ezetimibe and the oral bioavailability and also reduce the fluctuations in the oral bioavailability

A survey of the offshore demersal fisheries of the Andhra and Orissa coasts, with special reference to the biological data collected during 1960

Relatively little is known of the offshore fisheries potential of the Bay of Bengal. Previous records deal chiefly with either the deep-sea deposits and biology of the fauna in depths exceeding 200 metres (Alcock, 1889, 1890 a, b, c, 1891 a, b, c, 1892 a, b, 1893, 1894, 1895, 1896, 1898, 1899 a, b, 1902; Annandale, 1908; Borodin, 1930, 1932; Bolin, 1946; Lloyd, 1909; MacArdle, 1901; Sewell, 1912) or the intertidal and shoreline fauna (Alcock, 1890 a-c, 1892 a-c; Arora and Banerji, 1957; Blyth, 1861; Carpenter, 1885; Chacko, 1949; Day, 1878; Gravely, 1941, 1942; Jenkins, 1912; Koumans, 1941; Norman, 1927; Russell, 1803; Satyamurti, 1952, 1956). The Bengal Government Steam Trawler 'Golden Crown' made a few hauls of the Orissa Coast in intermediate depths in 1909-1910 (Anon., 1911; Jenkins, 1911; Annandale, 1909, 1910 a,b). In 1950, the West Bengal Government initiated a regular fishing program with two Danish trawlers, and in 1956 three Japanese trawlers were added to the fleet

Ab initio and DFT studies on structure, vibrational spectra of 4-tert-butyl-1,3-thiazol-2-amine (BTA)

Theoretical studies have been carried out on 4-tert-butyl-1, 3-thiazol-2-amine (BTA) using both the B3LYP/6-311+G and HF/6-311+G methods. The geometrical parameters and vibrational spectra of BTA have been calculated and analyzed. The calculated IR wavenumbers have been compared with the observed FTIR wavenumbers. The complete assignments have been performed based on the potential energy distribution (PED) of the vibrational modes. The wavenumbers obtained from B3LYP method are in good agreement with the observed wavenumbers when compared to HF method. It has been found that there is an excellent correlation with 0.999 regression coefficient between the experiment and calculated vibrations. Thermal properties like rotational constants, zero point vibrational energies and nonlinear optical properties like dipole moment, hyperpolarizabilities, NBO analysis and the effect of temperature on various thermodynamic properties have been calculated and orted

Formulation studies on cyclodextrin complexes of Meloxicam

ABSTRACT β-Cyclodextrin (β-CD) and HP-β-Cyclodextrin (HP-β-CD) inclusion complexes of piroxicam (PRX) exhibited higher dissolution rates and dissolution efficiency values than the corresponding un-complexed drug. The feasibility of formulating the β-cyclodextrin and HP-β-cyclodextrin complexes of piroxicam (1:3) into tablet dosage forms is evaluated. Solid inclusion complexes of piroxicam prepared by kneading method were formulated into tablets by wet granulation and direct compression methods. All the tablets formulated employing β-cyclodextrin and HP-β-cyclodextrin complexes of piroxicam gave rapid and higher dissolution rates of when compared to that of piroxicam plain tablets. All the prepared tablets fulfilled the official (I.P.) disintegration time specification of uncoated tablets. Overall, tablets prepared by direct compression method disintegrate rapidly when compared to those prepared by wet granulation method. Analysis of dissolution data as per zero-order and first -order kinetic models indicated that the dissolution of piroxicam from all the tablets followed first-order kinetics. In both direct compression and wet granulation methods, tablets formulated employing cyclodextrin complexes (PRXT2, PRXT3, PRXT5, PRXT6) gave higher rates of dissolution (K 1 ) and dissolution efficiency (DE 30 ) values when compared to the corresponding tablets formulated with piroxicam as such (PRXT1, PRXT4). Among all the piroxicam tablets formulated, formulation PRXT2, which is based on PRX-βCD (1:3) kneaded complex, gave highest dissolution. A 17.0 fold increase in the dissolution rate of piroxicam was observed with PRXT2 when compared to its plain tablets ( PRXT1)