ABSTRACT
There are four phases through which all pharmaceuticals pass before their release
onto the market. Although the phases are not rigidly defined and activities in
some phases overlap with others, broadly speaking, they can be described as
lead compound identification and optimization, formulation, process optimiz-
ation and scale up, and regulatory review/market release. Typically, several candidate compounds result from the lead identification step. Once these active
pharmaceutical ingredients (APIs) have been identified, they undergo a battery
of tests to identify their fundamental physicochemical properties. Based upon
the results of these tests, the number of APIs is whittled down to two or three can-
didates before a final selection process. Collectively, these tests are usually
known as preformulation (1). The preformulation stage is therefore a very
complex, time consuming but vital step in the process of getting a new product
to market.
