ANESTHETIC COMPOSITIONS WITH DELAYED RELEASE AND METHODS FOR THEIR PREPARATION Russian patent published in 2023 - IPC A61K31/167 A61K31/445 A61K47/24 A61K47/28 A61K9/00 A61K9/107 A61K9/127 A61P23/02 

FIELD: pharmaceutics.

SUBSTANCE: group of inventions relates to a method for obtaining an anesthetic composition with delayed release and to a composition for local administration of an anesthetic to a subject in need obtained by this method. A method for obtaining a delayed-release anesthetic composition involves: dissolving a lipid mixture and at least one amide-type anesthetic in a solvent system to obtain a liquid structure; removal of a solvent system from a liquid structure where the solvent system contains tert-butanol or tert-butanol/water as a co-solvent, to obtain a lipid structure with a high degree of capture (HELS); hydration of HELS using an aqueous buffer solution at a pH of 5.5 to 8.0. Moreover, as a result of hydration of HELS, multilayer vesicles (MLV) with a captured amide-type anesthetic are formed; moreover, the median diameter of MLV vesicles with a captured amide-type anesthetic is at least 1 mcm; and the molar ratio of an amide-type anesthetic and phospholipid in MLV vesicles with a captured amide-type anesthetic is at least 0.5:1. The anesthetic composition obtained by the above method contains multilayer vesicles with a captured amide-type anesthetic, the median diameter of which is at least 1 mcm, and the molar ratio of an amide-type anesthetic and phospholipid in the specified vesicles is at least 0.5:1.

EFFECT: use of the composition obtained by the above method provides a rapid onset of anesthesia and a prolonged duration of local anesthesia with minimal toxicity.

12 cl, 5 dwg, 2 tbl, 5 ex