FORMULATION AND EVALUATAION OF COLON TARGETED MATRIX TABLET OF NAPROXEN

Objectives: The objective of the present study is to formulate the Colon targeted delivery containing Naproxen for chronopharmaceutical drug delivery system (ChrDDS) for treatment of rheumatoid arthritis, which are influenced by circadian rhythm. Chronopharmaceutical drug delivery system is capable of delivering drug when and where drug required most. Naproxen would remain in the GIT Fluid, intestinal fluid and it will liberate only in colonic fluid and gives better absorption. Methods: The matrix core tablets of Naproxen were prepared by direct compression method by using Crosspovidone as superdisintegrant. From those optimesd batch core tablet is further going for coating. Coating was carried out by using natural gums like Xanthan gum, Guar gum, Chitosan and Pectin alone and in combination. Results: From the experimental work Crosspovidone shows good drug release. Coating done by combination of Xanthan Gum and Chitosan shows better drug release (98.24%) in sustained release manner than other natural gums like Guar gum and pectin. Conclusion: From the results obtained, it was concluded that the programmable Chronopharmaceutical drug release has been achieved from Crosspovidone containing core tablet compressed coated by combination of Xanthan gum and Chitosan over a 10 hrs period, consistent with the demands of chronotherapeutic drug delivery for rheumatoid arthritis

FORMULATION AND EVALUATION OF SUSTAINED RELEASE MATRIX TABLETS OF NATEGLINIDE

The objective of this work was to prepare and evaluate oral sustained release matrix tablet of Nateglinide and to study the effect of proportion of wax and addition of release liner on in-vitro release of drug.The prepared tablets were evaluated for pre and post compression parameters. Stability study of the promising formulation was also performed. The matrix tablets were prepared by Direct compression, Co-processed & melt granulation, method using wax in concentration 25%, 35% & 45% and evaluated for on in-vitro drug release using Compritol & Precirol. No interactions were found between drug and excipients. Formulation containing 25% Precirol F13 shows releases up to 12 hours. Tablets with release characteristics offers critical advantages such as site specificity with improved absorption and efficacy etc. Keywords: Nateglinide, Sustained release, Compritol 888, Precirol ATO 5, Melt Granulation, Direct compression

A REVIEW ON A FLASH CHROMATOGRAPHY

ABSTRACT Flash chromatography is rapid form of preparative column chromatography-preparative liquid chromatography based upon an air pressure driven hybrid of medium and short column chromatography optimized for rapid separation of organic compounds. As technology has evolved available guidelines for normal-phase flash chromatography have become less relevant. Years of experience performing chromatography with disposable columns have been condensed into simple guidelines useful for translating TLC results into either isocratic-or gradient-flash chromatography. The described studies should provide researchers with a means of selecting adequate columns and guidelines to reduce the waste of solvents, silica, time, and money. Modern flash chromatography systems are sold as pre-packed plastic cartridges and the solvent is pumped through the cartridge. These systems may also be linked with detectors and fraction collectors providing automation. The introduction of gradient pumps has resulted in quicker separations and less solvent usage

Induced magnetism in transition metal intercalated graphitic systems

We investigate the structure, chemical bonding, electronic properties, and magnetic behavior of a three-dimensional graphitic network in aba and aaa stacking with intercalated transition metal atoms (Mn, Fe, Co, Ni, and Cu). Using density functional theory, we find induced spin-polarization of the C atoms both when the graphene sheets are aba stacked (forming graphite) and aaa stacked (resembling bi-layer graphene). The magnetic moment induced by Mn, Fe, and Co turns out to vary from 1.38 {\mu}B to 4.10 {\mu}B, whereas intercalation of Ni and Cu does not lead to a magnetic state. The selective induction of spin-polarization can be utilized in spintronic and nanoelectronic applications.Comment: 13 pages, 3 figures, 1 tabl

New Particles Working Group Report of the Snowmass 2013 Community Summer Study

This report summarizes the work of the Energy Frontier New Physics working group of the 2013 Community Summer Study (Snowmass)

Kondo Effect on Mesoscopic Scale (Review)

Following the discovery of the Kondo effect the bulk transport and magnetic behavior of the dilute magnetic alloys have been successfully described. In the last fifteen years new directions have been developed as the study of the systems of reduced dimensions and the artificial atoms so called quantum dots. In this review the first subject is reviewed starting with the scanning tunneling microscope (STM) study of a single magnetic impurity. The next subject is the reduction of the amplitude of the Kondo effect in samples of reduced dimension which was explained by the surface magnetic anisotropy which blocks the motion of the integer spin nearby the surface. The electron dephasing and energy relaxation experiments are discussed with the possible explanation including the surface anisotropy, where the situation in cases of integer and half-integer spins is very different. Finally, the present situation of the theory of dynamical structural defects is briefly presented which may lead to two-channel Kondo behavior.Comment: 8 pages, submitted to the JPSJ Special Issue "Kondo effect -- 40 years after the Discovery

Optimal networks for Quantum Metrology: semidefinite programs and product rules

We investigate the optimal estimation of a quantum process that can possibly consist of multiple time steps. The estimation is implemented by a quantum network that interacts with the process by sending an input and processing the output at each time step. We formulate the search of the optimal network as a semidefinite program and use duality theory to give an alternative expression for the maximum payoff achieved by estimation. Combining this formulation with a technique devised by Mittal and Szegedy we prove a general product rule for the joint estimation of independent processes, stating that the optimal joint estimation can achieved by estimating each process independently, whenever the figure of merit is of a product form. We illustrate the result in several examples and exhibit counterexamples showing that the optimal joint network may not be the product of the optimal individual networks if the processes are not independent or if the figure of merit is not of the product form. In particular, we show that entanglement can reduce by a factor K the variance in the estimation of the sum of K independent phase shifts.Comment: 19 pages, no figures, published versio