The present invention relates to pharmaceutical compositions containing a solid dispersion of N-[2,4-B is( 1, 1 -dimethylethyl)-5-hydroxyphenyl]- 1,4-dihydro-4-oxoquinoline-3- carboxamide including formulations of the solid dispersions into powders, granules and mini- tablets, methods for manufacturing and processing the powders and mini-tablets and methods for treating cystic fibrosis employing the pharmaceutical composition.