The present invention relates to a pharmaceutical composition in solid oral dosage form comprising (R)-7-(2-(1-(4-butoxyphenyl)-2-methylpropan-2-ylamino)-1-hydroxyethyl)-5-hydroxybenzo[d]thiazol-2(3H)-one acetate salt.L'invention concerne une composition pharmaceutique sous forme dosifiée orale solide contenant un sel de (R)-7-(2-(1-(4-butoxyphényl)-2-méthylpropan-2-ylamino)-1-hydroxyéthyl)-5- hydroxybenzo[d]thiazol-2(3H)-one acétate.