1. A method of producing a sustained release tablet, comprising: a) wet granulating a first portion of the active ingredient and at least one inactive ingredient to produce wet granulate； b) drying the wet granulate； c) grinding the dried granulate； d) mixing the crushed granulate at least with at least one external phase； e) compressing the mixture to form a tablet core； f) coating the tablet core with at least one inner coating layer containing at least a first polymer and a first plasticizer； g) p coating a tablet coated with an inner layer of at least one enteric coating layer containing at least one enteric substance； h) coating a tablet coated with an enteric layer with at least one active layer containing a second portion of at least one active ingredient, a second a polymer and a second plasticizer, ii) coating a tablet coated with an active layer with at least one outer coating layer containing at least a third polymer and a third plasticizer； where step h) includes t produce a homogeneous suspension containing the active ingredient, a second polymer and a second plasticizer by stirring for about one hour and spraying the homogeneous suspension onto an enteric coated tablet for about twenty hours, where the homogeneous suspension is continuously mixed during spraying. 2. The method of claim 1, wherein the active ingredient comprises tetracycline. The method of claim 2, wherein the active ingredient comprises doxycycline. The method according to claim 1, where at least one inactive ingredient1. Способ получения таблетки с длительным высвобождением, включающий:a) влажное гранулирование первой порции активного ингредиента и по меньшей мере одного неактивного ингредиента с получением влажного гранулята；b) сушку влажного гранулята；c) измельчение высушенного гранулята；d) смешивание измельченного гранулята по меньшей мере с одной внешней фазой；e) прессование смеси с получением ядра таблетки；f) покрытие ядра таблетки по меньшей мере одним внутренним слоем покрытия,
