Phthalonitrile polymers with amide and ortho-, meta-, and para-substituted ether linkages in the backbone were synthesized successfully and their thermal properties were investigated. The monomer building blocks for these polymers were cured without the addition of catalysts due to the self-catalyzing nature of the monomer's amino group. The ether and amide functionalities in the chain enhanced their processability without compromising thermal stability. The resins exhibited a low complex viscosity over a wide processing window between the monomer melting temperature and the polymer cure temperature, with the processing temperature range varying significantly for para-, ortho-, and meta-substituted polymer architectures. All three systems exhibited high thermal and thermo-oxidative stability. The high char yields, which ranged from 66-75% at 900 °C under nitrogen atmosphere, and the high glass transition temperatures of the polymers indicate a high crosslinking density in the network structure.

Some new amino-and imide-containing phthalonitrile compounds with 1:1 molar ratio of amino group to pthalonitrile unit were successfully synthesized. The molecular structures were characterized by spectroscopic techniques. They were thermally polymerized under nitrogen/air, even in the absence of curing additives. The thermal properties of the cured products were characterized by thermogravimetric analysis and differential scanning calorimetry. The 5% weight loss temperatures ranged from 525 to 528 C and 513 to 520 C under nitro-gen and air, respectively. Char yields (900 C) were in the range of 62-70%. Rheometric measurements showed that the rate of the cure reaction differs for all the three monomers. The glass transition temperature advances with increasing extent of cure and disappears on postcure at 375 C. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 5916-5920, 2010

This article describes the synthesis and properties of phthalonitrile polymers prepared from three different ortholinked monomers, namely 2,2 -bis(3,4-dicyanophenoxy)biphenyl, 1,2-bis(3,4-dicyanophenoxy)benzene and 2,2 -bis(3,4dicyanophenoxy)-1,3,4-oxadiazole. The resins exhibited a low complex viscosity, with a varying range of processing temperatures for all three systems. Thermogravimetric analysis showed that the synthesized polymers exhibited high thermal and thermo-oxidative stability. The high char yields, which ranged from 64 to 69% at 900 • C under nitrogen atmosphere, and the high glass transition temperatures of the polymers indicated a high crosslinking density in the network structure. Dynamic mechanical measurements demonstrated that the fully cured monomer 2,2 -bis(3,4-dicyanophenoxy)-1,3,4-oxadiazole exhibited no change in glass transition temperature or in storage modulus up to 500 • C.

Abstract. Controlled-release (CR) tablet formulation of olanzapine was developed using a binary mixture of Methocel® K100 LV-CR and Ethocel® standard 7FP premium by the dry granulation slugging method. Drug release kinetics of CR tablet formulations F1, F2, and F3, each one suitably compressed for 9-, 12-, and 15-kg hardness, were determined in a dissolution media of 0.1 N HCl (pH 1.5) and phosphate buffer (pH 6.8) using type II dissolution apparatus with paddles run at 50 rpm. Ethocel® was found to be distinctly controlling drug release, whereas the hardness of tablets and pH of the dissolution media did not significantly affect release kinetics. The CR test tablets containing 30% Methocel® and 60% Ethocel® (F3) with 12-kg hardness exhibited pH-independent zero-order release kinetics for 24 h. In vivo performance of the CR test tablet and conventional reference tablet were determined in rabbit serum using high-performance liquid chromatography coupled with electrochemical detector. Bioavailability parameters including C max , T max , and AUC 0-48 h of both tablets were compared. The CR test tablets produced optimized C max and extended T max (P<0.05). A good correlation of drug absorption in vivo and drug release in vitro (R 2 =0.9082) was observed. Relative bioavailability of the test tablet was calculated as 94%. The manufacturing process employed was reproducible and the CR test tablets were stable for 6 months at 40±2°C/75±5% relative humidity. It was concluded that the CR test tablet formulation successfully developed may improve tolerability and patient adherence by reducing adverse effects.

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Antibacterial and antifungal activities of the two isolated compounds from Conyza canadensis have been reported in the current study. The two isolated compounds i.e. Conyzolide (1) and Conyzoflavone (2) were tested against six bacterial and five fungal strains, employing hole diffusion and macrodilution methods. Both the compounds showed significant activities against the tested pathogens with special reference to E. coli, P. aeruginosa, S. aureus, Trichophytom longifusus, C. albicans, and C. glaberata. Conyzolide revealed comparatively better antibacterial activity against E. coli (minimum inhibitory concentration (MIC): 25 µg/mL) in comparison to Conyzoflavone. However, in case of antifungal activities, Conyzoflavone exhibited superior antifungal activity against C. albicans (MIC: 10 µg/mL) as compared to Conyzolide.

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In this study we screened various crude fractions of