Biopharmaceuticals, unlike chemically synthesized small-molecule drugs, are marginally stable, with most of them requiring 3D structures to retain their activity and/or potency. This implies challenges to formulate these molecules for a shelf life >2 y of and also to minimize the cost of goods for manufacturing. Patient compliance has become a key consideration in the design and development of suitable dosage forms in the modernized world. Thus, here we describe different classes of biological therapeutic, with an emphasis on molecular properties, formulation challenges, and development strategies. We also present statistics on the different classes of approved biologic drugs and dosage forms.