Development

Once a candidate compound with optimal characteristics has been identified it enters the development phases.

Process chemistry

Process Chemistry, as the name implies, relies on the in depth understanding of chemical reactions to convert what is often no more than "a mode of formation", suitable for making milligrams of a compound, into a robust, scalable and economic synthesis that can be used to make kilograms of a drug candidate.

Toxicology & safety

Although basic toxicology parameters will have been assesed in lead optimisation,  a series of in vitro and in vivo studies will be performed in the development phase, usually to registration standards and protocols, in order to fully determine the toxicity profile and therapeutic index, maximum doses for safe administration etc. These will usually be performed in at least two species and should determine both specific (mechanism related) and non-specific (chemical) side effects which could limit the safe dose which can be used in man. If the mechanism is human specific and doesn't occur in man these studies will be limited to non-specific toxicology with ex-vivo human studies etc being implemented to assess the mechanism related effects. The duration and number of dose levels used in these studies will be determined by the drug exposure, length and protocols of the proposed initial (Phase I/II) clinical studies in man.  Studies will also be performed to assess the broader safety effects such as behavioural and physiological effects in vivo.

Pharmaceutical development

The actual delivery to the drug target in man is to a large extent dependant upon delivering the compound via an optimal route of delivery and formulation i.e. combining the pure drug substance with ingredients to optimise its delivery, stability etc. Thus a recipe is designed that combines the optimal chemical form of drug substance with other ingredients to create a final formulation ie tablet, injection, inhalation device etc.

Ways in which clinical testing will  be carried out need to be developed at this stage.