Developing generic versions of complex drug products presents a number of challenges as a result of the nature of their formulation or their route of delivery. In response to this, regulators, including the US FDA, have released product-specific guidance aimed at advising generics manufacturers on the approaches which may be applied to prove bioequivalence in vitro through the measurement of a complex drug product’s physicochemical properties.

In this webinar, we considered the regulatory guidance available for nano drug delivery systems such as liposomes, parenteral emulsions and iron sucrose complexes. These products are considered complex formulations due to the importance of the drug delivery system’s structure and stability in determining the post-delivery fate of the drug product, along with its bioavailability at the site of action. Product-specific guidance documents from the US FDA, along with general guidance from the EMA and Japanese regulators, highlight the importance of physicochemical properties such as particle size and particle charge, along with the formulation structure, phase behavior and rheology, in assessing drug product bioequivalence. We considered how this guidance can be followed and will also consider the additional insight which can be obtained through the application of physicochemical analysis techniques in order to aid prototype formulation development and optimization.