Structural properties of a protein residue's microenvironment have long been implicated as agents of selective constraint. Although these properties are inherently quantitative, structure-based studies of protein evolution tend to rely upon coarse distinctions between "surface" and "buried" residues and between "interfacial" and "noninterfacial" residues. Using homology-mapped yeast protein str...

piroxicam (px), an anti-inflammatory drug, exhibits poor water solubility, dissolution and flow properties. thus, the aim of the present study was to improve the solubility and dissolution rate of px by freeze drying technique using dimethylformamide (dmf), chloroform and water as co-solvent system. the prepared crystals containing px were evaluated for dmf and chloroform solvent residual by ga...

The wavenumbers of the IR absorption bands of the C=O, S=O and N-H stretching vibrations for a series of p-substituted N-phenylsulfonylbenzamides were measured in trichloromethane. The bond orders, Mulliken charges, charge densities and heats of formation were calculated using the PM3 method. Fifty significant mutual mono parameter (MP) and six dual parameter (DP) correlations were found for th...

A systematic and quantitative methodology for synthesis of gas separation networks is being developed to allow generation of effective and economic separation schemes. Synthesis includes selection of appropriate separation methods, e.g. absorption, lowtemperature separation processes and membrane permeation. In the screening step of the methodology, a quick assessment of alternative separation ...

Solvent exchange facilitates high-density nucleation of sessile nanodroplets or nanobubbles by successively wetting a surface with two solvents contrasting solubility respect to target species. Yet the key physical mechanisms underlying its efficacy have yet be theoretically explained. We develop minimal model for solvent exchange, prototypical example water and ethanol as nitrogen Our calculat...

At present, physical chemistry employs the tools of thermodynamics to treat osmosis across a semipermeable membrane. We propose a model in terms of momentum transfer, the inherent asymmetry of which leads quantitatively to the van't Hoff relationship; qualitatively, the solute molecules can be looked upon as micropumps that suck solvent through the pores in the membrane.

Powder particle coating is the most important techni It has constantly being refined and modified since last four decades. There numerous applications of coating, including drug layering, modified release coating, physical and chemical protection, aesthetic purpos identification of drugs. Various coating techniques from conventional pan coating to laser assisted solvent free techniques have bee...

Organic molecules including most of pharmaceutical compounds are prone to polymorphic formation in the solid state. Because of the variation in crystallization environment (e.g., solvent, temperature, using of additives, and concentration), the same molecules can pack differently and form different crystal lattices or polymorphs. As a result, the physical, chemical and mechanical properties of ...