A pharmaceutical composition is prepared by the steps of dispersing a phospholipid uniformly in water to give an aqueous phospholipid dispersion, adding a medicament to the aqueous dispersion, freezing the thus-obtained aqueous dispersion, thereby entrapping the medicament in the lipid spherules, and then thawing the frozen dispersion to give an aqueous suspension of the medicament entrapped in the lipid spherules having a diameter of less than 5.0 mu . The pharmaceutical composition prepared above is used as a controlled release pharmaceutical preparation.
