1. A solid dispersion of rifaximin containing rifaximin and a pharmaceutically acceptable carrier. The solid dispersion according to claim 1, wherein the pharmaceutically acceptable carrier is selected from urea, sugar, organic acids, polyethylene glycol, povidone, copovidone, polymethacrylates, polyvinyl acetate, cellulose derivatives, self-emulsifying carriers, poloxamer, glyceryl behenate, polyethylene derivative of monoglyoxyethylene, vitamin E, hydroxyl stearic acid ester, polyoxyl glycerides, polyethoxylated castor oil, or combinations thereof. 3. The solid dispersion according to claim 1, increasing the solubility of rifaximin compared with an equivalent amount of rifaximin. The solid dispersion according to claim 3, wherein the solubility of rifaximin increases by more than 30% .5. The solid dispersion according to claim 1, increasing the gastrointestinal availability of rifaximin compared to an equivalent amount of rifaximin. A solid dispersion of rifaximin, where the solubility of rifaximin in a solid dispersion is increased compared to an equivalent amount of rifaximin, while equivalent permeability is maintained compared to an equivalent amount of rifaximin. 7. A pharmaceutical composition comprising a solid dispersion according to claim 1.8. A method of treating and / or preventing a microbial infection, wherein a therapeutically effective amount of a solid dispersion of rifaximin according to claim 1 is administered to a patient in need thereof.1. Твердая дисперсия рифаксимина, содержащая рифаксимин и фармацевтически приемлемый носитель.2. Твердая дисперсия по п.1, где фармацевтически приемлемый носитель выбирают из мочевины, сахара, органических кислот, полиэтиленгликоля, повидона, коповидона, полиметакрилатов, поливинилацетата, производных целлюлозы, самоэмульгирующихся носителей, полоксамера, глицерилбегената, полиэтиленового производного моноглицерида, витамина E, полиэтиленового или полиоксиэтиленового сложного эфира гидроксилстеариновой кислоты,
