FIELD: medicine, hormones, pharmacy. SUBSTANCE: invention relates to the development of preparation with prolonged effect comprising antagonists of luteinizing hormone-releasing hormone, especially, cetrorelix based on complex with suitable biophilic carriers providing the directed release of active compound for some weeks. For complex formation acid polyamino acids (polyglutamic and polyaspartic) are used with average molecular mass 5 000-20 000 g/mole. Complexes of cetrorelix with polyamino acids are formed by precipitation from aqueous solutions in combination of component solutions followed by separation of precipitate by centrifugation and drying by lyophilization. Experiments with animals have shown the principle effectiveness of complexes of cetrorelix with polyamino acids as sustained- release preparations. Owing to binding cetrorelix with polyamino acids the duration of suppression of testosterone in complex in male mice is above 600 h. Release of active compound can be regulated depending on type of polymer and its molecular mass. The advantage of invention is the development of the novel sustained-release preparation. EFFECT: improved preparing method, valuable medicinal properties of complex. 7 cl, 1 tbl, 4 dwg, 5 ex
