Drug design for pharmacokinetic problems

Drug design aimed at solving any or all of the above problems can involve a lot of trial and error, basically because of the many variables involved. However, there are some strategies which can be usefully employed. 

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To develop platinum drugs with improved properties compared to cisplatin, a plethora of cisplatin analogs have been designed with appended additional ftmctionalities. The rationale is that these incorporated moieties could lead to a host of favorable pharmacokinetic properties, such as targeting to cancer cells, improved transport into the cell, and increased affinity for DNA. Furthermore, to overcome the problem of resistance, pendant DNA interacting moieties have been... 

Many discovery leads are transferred to the preclinical development process with insufficient characterization to assess their development potential. This lack of knowledge usually results in poorly designed experiments that are not data productive and that, in many cases, have to be repeated when the drug candidate shows unexpected toxicity, low and variable delivery, instability or solubility problems, or unacceptable pharmacokinetic and drug metabolism profiles. In all too many cases, the recognition of these problem areas results in termination of development for a potentially useful therapeutic agent. At best, the problems encountered cause a delay, at times substantial, in the development of a candidate while additional studies are conducted to elucidate the causes of the problems and minimize their effects. Then the definitive development experiments have to be repeated. 

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