Drug development safety studies

Safety pharmacology satisfies a key requirement in the process of drug development. Safety pharmacology studies are required to assess the impact of a new... 

Safety and quality aspects are the main topics that must be addressed from a regulatory perspective at the pre-clinical phase of drug development. Indicative efficacy data will also be obtained, but authoritative data can be obtained only from clinical studies conducted with humans. Safety and preliminary efficacy indications... 

This chapter will review some of the important methods for carrying out in vivo absorption and bioavailability studies, as well as attempt to provide an overview of how the information may be used in the drug discovery process. The chapter is aimed at medicinal chemists and thus will focus on the use of animals in discovery phase absorption, distribution, metabolism, and excretion/pharmacokinetic (ADME/PK) studies, rather than the design of studies that are for regulatory submission, or part of a development safety package. 

Although prediction of ADME/PK in man may be the primary purpose for the pre-clinical studies, it is also important that potential new drugs have acceptable properties in toxicology species. Without these it can be very difficult to generate adequate safety margins to allow studies in man to start. It is also likely that the development safety assessment program will be difficult and hence slow. 

It is not clear how the immense base of knowledge generated under the various rubrics of genomics will ultimately be utilized to improve drug safety and the drug development process. What is clear, however, is that it will be some years before such studies displace the current paradigm of testing. 

The initiative to add mandated safety pharmacology studies to the drug development process is overdue in arriving. However, its actual implementation and the use of the resulting data in risk/benefit decision will take some time to be worked out. During the year 2001, many small companies were put in a difficult position when the... 

The degree of exposure of the fetus to a particular substance can be best assessed in human subjects, but concerns of fetal safety have restricted the use of this approach. Moreover, clinical studies cannot elucidate the various mechanisms that contribute to transplacental transport of a particular compound. There are many structural differences between the human placenta and the placenta of other mammalian species, which complicates extrapolation of data obtained from in vivo animal models to humans [7], Thus, several ex vivo and in vitro techniques have been developed to study the placental role in drug transfer and metabolism during pregnancy and there are some excellent articles that discuss these systems in detail [7], Both isolated tissues and various cell culture techniques are currently in use and these have been summarized below. 

Most workshop participants recommended that data to be used to support drug safety and efficacy for registration should have a link to the patient record. In addition, samples linked to patients data have potential for use in subsequent validation studies that are unanticipated at the outset of drug development. 

As most individuals involved in drug development know only too well, the ultimate safety assessment of any new drug comes from extensive clinical studies. However, prior to its first introduction into humans, and generally continuing through the clinical... 

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