A biodegradable drug delivery compositions comprising a triblock copolymer containing a polyester and a polyethyl-ene glycol and a diblock copolymer containing a polyester and an end-capped polyethylene glycol, as well as at least one pharmaceutically active principle or hydrophobic active principle such as medroxyprogesterone acetate, levonorgestrel, cyclosporine, progesterone or bupivacaine is disclosed.
