Preformulation studies biopharmaceutical drug

Preformulation testing encompasses all studies enacted on a new drug compound in order to produce useful information for subsequent formulation of a stable and biopharmaceutically suitable drug dosage form. 

Several substance properties can affect dissolution and/or solubility, such as purity particle size and distribution surface area and the presence of polymorphs, hydrates or other solvates or amorphous forms. To avoid misleading or inconclusive results in extensive solubility or dissolution studies, it is important to characterise the drug substance form with respect to such properties, especially in the later biopharmaceutical preformulation phase. Methods for such characterisation are described in more detail in Chapters 3 and 7. 

The physicochemical tests, in vitro methods and animal experiments used in the biopharmaceutical preformulation phase can never fully reflect the conditions in man, and studies of the drug absorption prerequisites can therefore be very valuable. This is especially relevant if (a) contradictory results have been obtained in model experiments, (b) the substance has complicated absorption properties (e.g., active transport) or (c) a modified release formulation will be developed. The most important information that can be obtained in such human studies is... 

For pharmaceutical development, risk may be associated with the technical challenges anticipated in developing a novel or complex drug delivery system or manufacturing process. Information from early preformulation and biopharmaceutics studies should indicate the potential problems for drug delivery, formulation development and manufacture. 

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