the aim of this study was to develop a derivative of chitosan as pharmaceutical excipient used in sustained-release matrix tablets of poorly soluble drugs. a water-soluble quaternary ammonium carboxymethylchitosan was synthesized by a two-step reaction with carboxymethylchitosan (cmcts), decylalkyl dimethyl ammonium and epichlorohydrin. the elemental analysis showed that the target product with...

An in situ IR technique was applied in the selective synthesis of the key intermediate for rapamycin derivatives, which made the reaction endpoint easily defined. This technology solved a bothersome problem in the preparation of rapamycin derivatives, and based on this technique, the 31-OH and 42-OH of rapamycin were chemically modified by a series of quaternary ammonium salts to generate 11 co...

New amphiphilic ABC triblock copolymers have been designed and self-assembled into water-dispersible and biodegradable polymer micelles, which exhibit good antibacterial activities without quaternary ammonium moieties or the loading of any external antibiotics due to the increased local concentration of cationic charge in the polymer micelles compared to the un-self-assembled individual polymer...

Introduction: Biocides are commonly used for disinfection in a variety of contexts. They generally to avoid infection by controlling biofilm on medical equipment. However, the literature lacks information effect biocide efflux pump gene expression. Objective: To determine influence development and acrA ramA Methodology: The microtiter plate method was identify 80 isolates K. pneumoniae. minimal...

The antibacterial effect of 11 new commercially manufactured disinfectants on clinical isolates of Salmonella typhimurium DT104, Serratia marcescens and Pseudomonas aeruginosa was studied. The substances tested represented six pure quaternary ammonium substances (QAS) and five QAS combined with other ingredients. The antibacterial efficacy was characterized by influencing the growth of bacteria...

Branched quaternary ammonium molecules were synthesized and characterized by calorimetric, optical and X-ray diffraction studies; two of the molecules exhibited interesting nematic liquid crystalline behavior close to room temperature.