The Rome-based club finished ninth last term but have since appointed Stefano Pioli as their new coach.
And Lotito revealed that the club are working on making additions to their squad as they seek to return former glories.
"Lazio are working on getting some defining purchases," Lotito said in a statement as quoted by Football Italia.
"They will be considerable in terms of human and professional qualities.
"We believe in improving the team and we are working to do so for next season – we want to reach some big goals.
"I hope fans can grasp the importance of this moment and can get behind us with all their enthusiasm."
Lazio have already signed Nantes striker Filip Djordjevic, who scored 10 Ligue 1 goals last term.