Highly concentrated drug particle formulations are described, wherein the drug comprises between about 25 wt% and 80 wt% of the particle formulation. The particle formulations of the present invention comprise, for example, macromolecules, such as proteins and/or small molecules (such as steroid hormones). The particle formulation typically further includes one or more additional component, for example, one or more stabilizer (e.g., carbohydrates, antioxidants, amino acids, and buffers). Such concentrated particle formulations can be combined with a suspension vehicle to form suspension formulations. The suspension formulation comprises (i) a non-aqueous, single-phase vehicle, comprising one or more polymer and one or more one solvent, wherein the vehicle exhibits viscous fluid characteristics, and (ii) a highly concentrated drug particle formulation. Devices for delivering the suspension formulations and methods of use are also described. The present invention provides needed improvements in drug formulation and delivery to improve patient compliance and expand drug availability.
