MICRON AND SUBMICRON-SIZE MICROBEADS WITH POLYMER WRAP AND METHOD OF MANUFACTURING THEREOF Russian patent published in 1998 - IPC

FIELD: chemical-pharmaceutical industry. SUBSTANCE: invention focuses on manufacturing air- or gas-filled microbeads surrounded by polymer wrap made of synthetic polymer and serving to inject or introduce into live organisms orally, rectally, or urethrally for therapeutic or diagnostic aims (echography). Properties of polymer membrane of microbeads (elasticity, permeability, biodegradability) can be regulated by way of choosing polymer, conditions under which deposition onto phase interface occurs, and polymer additives. Condensation of polymer in the suspension ranges from 0.00004 to some 400 mg/ml, thickness of the wrap 50 to 500 nm, and air or gas amount from 0.00003 to some 500 mcl per 1 ml of suspension. Microbeads are manufactured by depositing polymer substance onto phase interface, preparing oil-in-water emulsion, adding polymer insoluble in water phase, precipitating polymer, and removing encapsulated hydrophobic phase, which is evaporated simultaneously with water phase while replacing them by air or gas. EFFECT: facilitated manufacturing procedure. 22 cl