Microparticles on the Basis of Segmented Polyurethanes for Drug Respiratory Administration

Microparticles based on segmented polyurethane were synthesized by polycondensation of a series of diols having various molecular weight with tolyene-2,4-diisocyanate in water-in-oil emulsion. The resulting spherical microparticles were 6-10 µm in diameter following the Gauss distribution. The size of microcapsules at maximum distribution band increases with growing PEG length. It was observed that with higher length of PEG wall surfaces of capsules become more stable mechanically, however a capsule itself is no more brittle and rough. Some aggregation also occurs for microparticles based on PEG 4200. Since respiratory way of drug administration considers size of particles within 1-10 µm as the most applicable, the resulting PU microparticles could be an ideal candidate as domain for respirable antiTB drug administration