ABSTRACT
With only a few exceptions, for example, some inhalation products, active pharmaceutical
ingredients are converted to medicines through the thoughtful incorporation of excipients.
A potentially valuable drug substance, which could bring life-changing benefits to
millions of patients, can be rendered worthless by poor formulation, and equally, actives
of moderate properties can become valuable medicines by optimized delivery methods.
For the majority of medicines it can be expected that the combined excipient content in
the formulation will greatly exceed the mass of active. The selection of suitable excipients
and the proportions used will be determined on the basis of the desired route of
administration, the dose, the physicochemical properties of the active (preformulation is
covered elsewhere and will be the starting point for the process of excipient selection),
and the proposed method of manufacture for the product.
