Biological products are an important part of medical treatment and comprise a wide range of materials such as purified human blood components (e.g. albumin, immunoglobulins), vaccines, cell therapies or recombinant therapeutic proteins. The terms biological products, biologics, biologicals, biopharmaceuticals, biopharmaceutics and biotechnology will be defined, and we will discuss aspects of the formulation development of biological molecules, mainly recombinant therapeutic proteins, manufactured and purified using biotechnological methods. All biopharmaceuticals are, in general, fragile entities with highly specific biological targets and activities. Special formulations are required if the desired activity, both in terms of target and extent or duration, is to be achieved. The biotechnological pharmaceutical industry, with its efforts to find and manufacture medicines over the past two decades has discovered, sometimes by design, often by trial and error, and always by laborious effort, much of what works in biologicals and therapeutic protein formulation development. With increasing momentum, certain risks have been uncovered too. In this review, we present our experience in the formulation of recombinant proteins and the current state of awareness of some formulation risks. The importance of formulation is elaborated and experimental approaches to the development of a formulation for a biological molecule are detailed, including platforms for high-throughput formulation development. Some current challenges in the biopharmaceutical industry are discussed.