From single excipients to dual excipient platforms in dry powder inhaler products.

Recent years have seen a marked diversification of excipient based formulation strategies used for the development and commercialisation of dry powder inhaler (DPI) products. These innovative approaches not only provide benefits to patients and health care professionals through the availability of a wider range of therapeutic DPI products, but, importantly, also allow formulators to exploit the potential opportunities that excipients provide for the development of DPIs. Whilst many DPI products have, and continue to be developed using a single formulation excipient, the commercialisation of DPI products which contain the two excipients lactose monohydrate and magnesium stearate, namely the 'dual excipient platform' has recently been achieved. This article provides an overview of the background and current status of the development of such 'dual excipient platform' based DPI products.