Although there are no regulatory requirements or established pharmacopoeial techniques for the dissolution testing of inhaled
drugs, such testing can potentially open up the opportunity to tailor formulation properties. The authors explain how a new
technique using standard dissolution test equipment in combination with US Pharmacopeia methods for the dissolution testing
of solid dosage forms can be used to differentiate the solubility of orally inhaled products.
GEORGE DOYLE/GETTY IMAGES.
Dissolution testing of inhaled drugs is of significant interest to the developers of orally inhaled products (OIPs) that deposit
solid particles in the lung. As yet, there is no regulatory requirement or established pharmacopoeial technique for such testing,
but its relevance is clear; understanding and, in the longer term, learning to control the dissolution rate of an active (particularly
one for systemic therapy) opens up the possibility of tailoring formulation properties, as well as dosing levels and frequencies,
for improved drug efficacy and patient compliance.
Against this background, research has been conducted to establish a suitable method for dissolution testing of inhaled products.
This paper considers the need for this and describes a technique developed at the University of Texas at Austin (TX, USA).
Based on using standard USP dissolution test equipment for solid dosage forms, this new technique differentiates the solubility