Physico-chemical properties, such as molecular weight, size, solubility, partition coefficient and acid dissociation constant greatly impact on pharmacokinetics of traditional small molecule drugs and substantially utilized in the discovery and development of small drugs. However, it is extremely difficult to predict pharmacokinetic fate (absorption, distribution, metabolism and elimination) of protein therapeutics from their physicochemical parameters due to the macromolecular nature of therapeutic proteins and peptides. Their structural complexity and immunogenicity are other involved factors that determine their biological functions. Therefore, it is highly challenging to develop generalized strategies during the discovery of therapeutic proteins and peptides.