A solid composition comprising sofosbuvir and at least one pharmaceutically acceptable matrix compound wherein at least 99 weight-% of the sofosbuvir comprised in the composition are present in amorphous form, at least 99 weight-% of the solid composition consist of the sofosbuvir and the at least one matrix compound, and wherein the solid composition contains the sofosbuvir in an amount of at least 55 weight-% based on the combined weight of the sofosbuvir and the at least one matrix compound.