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International Journal of Pharmaceutics 201 (2000) 131 – 150 www.elsevier.com/locate/ijpharm Review

Biopharmaceutics and pharmacokinetics in drug research
Ramesh Panchagnula *, Narisetty Sunil Thomas
Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research, Sector 67, S.A.S. Nagar,
Punjab 160 062, India
Received 7 September 1999; received in revised form 6 January 2000; accepted 6 January 2000

Abstract
With the synergistic and multiplicative interactions of rational drug design, recombinant biotechnology, combinatorial chemistry and high-throughput screening, millions of compounds are being synthesized by chemists. However, development of these drug candidates has often been impeded, if not terminated, due to biopharmaceutic and/or pharmacokinetic constraints. This has resulted in delays in development time and escalation of cost in the drug research programmes. So, the present emphasis is to reduce development time and cost, which is analogous to added patent life besides the enormous reduction in human suffering. In this compilation the important biopharmaceutic and pharmacokinetic approaches are discussed, which will help in the development of safe and more efficacious drugs with reduced development time and cost. © 2000 Elsevier Science B.V. All rights reserved.
Keywords: New drug development; Biopharmaceutics; Pharmacokinetics; Solubility; Permeability; Lipophilicity

1. Introduction
Drug research is a unique multi-disciplinary process heading towards the development of novel therapeutic agents in areas of currently unmet medical need. The drug research can be divided functionally into two stages: discovery/design and development (Fig. 1). Drug discovery/design consists of identification and characterization of new targets (enzymes or receptors), synthesis of new
* Corresponding author. Tel: + 91-172-673848; fax: [phone].
E-mail address: [e-mail] (R. Panchagnula)

lead molecules,

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