Immobilization and release of etophylin from hydrogels, based on polyacrylic acid and macrodiisocyanates.

Hydrogels, based on polyacrylic acid and various macrodiisocyanates that contain polyethylene glycol, polypropylene glycol or polytetramethylene glycol in the main chain are synthesized. The obtained hydrogels are studied as possible polymer carriers of drug substances. Etophylin was applied as a model drug.

Hydrogels based on the chemically crosslinked polyacrylic acid: biopharmaceutical characterization.

This study is an attempt of biopharmaceutical characterization of hydrogels based on crosslinked polyacrylic acid (PAA). Macrodiisocyanates (MDIC) or oligomethanediisocyanate (DO) were used as crosslinking agents. The drug release rate from such hydrogels is determined by the density of the net and is lowered by a decrease in the PAA : MDIC mass ratio.

The electronic structure and spectra of Ru(II) and Ru(III) complexes with imidazole and its derivatives.

The calculations of the electronic structure and spectra of [Ru(NH3)5L]2+ (L = imidazole, histidine) and [Ru(NH3)5L]3+ (L = imidazole, N-imidazolate anion, 4-methylimidazole, 4-methyl-1N-imidazolate anion and 1N-bound histidine) complexes are performed in the framework of the CI method in the INDO/CNDO approximation. The MO diagram is obtained. The assignment of all transitions with energies of 4-5 eV is made and the nature of corresponding excited states is discussed.