Biopharmaceutical discovery phase

The annual R D expenditure for biopharmaceuticals is around US 19-20 billion. There are estimated to be 2500 biopharmaceuticals in the discovery phase, 900 in preclinical trials, and 1600 in clinical trials. This represents 44% of all drugs in the development phase and 27% of all drugs in both preclinical and clinical trials. The most common target is cancer and monoclonal antibodies and vaccines have the largest amount of R D activities. 

Many types of modeling techniques are available in the discovery phase of drug development, from structure activity relationships (SAR) to physiology based pharmacokinetics (PBPK) and pharmacokinetics-/pharmacodynamics (PK/PD) to help choosing some of the lead compounds. Some tests that are carried out by discovery include techniques related to structure determination, metabolism, and permeability NMR, MS/MS, elemental analysis, PAMPA, CACO-2, and in vitro metabolic stability. Although they are important as a part of physicochemical molecular characterization under the biopharmaceutics umbrella, they will not be discussed here. The reader can find relevant information in numerous monographs [9,10]. 

In the drug discovery process, the selection of a suitable candidate drug is the milestone for continuing into a costly development and clinical phase. Some optimal absorption criteria from a biopharmaceutical point of view are shown below ... 

More mechanistic studies in humans during Phase I must be performed for better feedback to discovery and pharmaceutical development, and thereby for faster performance through the clinical phases. It was recently suggested that a biopharmaceutical classification of drug permeability coefficients and dissolution issues must be determined early in the development program for rational drug design (Amidon 1996). 

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