The present invention provides a pharmaceutical composition comprising (a) a triblock copolymer having the formula: PLAv-PEGw-PLAx wherein v and x are the number of repeat units ranging from 1 to 3,000 and w is the number of repeat units ranging from 3 to 300 and v=x or v≠x in an amount of 22 to 34 w/w % of the total composition; (b) a diblock copolymer having the formula: mPEGy-PLAz wherein y and z are the number of repeat units with y ranging from 2 to 250 and z ranging from 1 to 3,000 in an amount of 5 to 9 w/w% of the total composition; (c) tacrolimus or a pharmaceutically acceptable salt, hydrate or solvate thereof in an amount of 8 to 32 w/w % of the total composition; and (d) organic solvent in an amount of 30 to 62 w/w % of the total composition.