FIELD: organic chemistry, medicine, pharmacy. SUBSTANCE: invention relates to solid pharmaceutical composition for oral administration comprising derivative of benzofuran eliciting anti-arrhythmic activity or one of its pharmaceutically acceptable salts as an active component and pharmaceutically acceptable surface-active substance being possibly in combination with one or more pharmaceutical excipient. Solid pharmaceutical composition for oral administration ensures to maintain solubilization of active component in neutral medium and decrease the degree of its absorption variation into human blood. EFFECT: improved properties of composition. 13 cl, 2 dwg, 13 tbl, 8 ex
