Sponsors frequently ask for our help in selecting an appropriate dosage form for their inhalation product. The decision of metered dose inhaler (MDI) versus dry powder inhaler (DPI) versus nebulized product is sometimes made based on marketing or competitive factors. For example, if there is an interest in a higher barrier-to-entry product, then a DPI may be an appropriate choice. But often the decision is based on the more technical considerations. For example, the expected indication, the target patient population, and the dose of the product are often the first screening questions that can steer us in one direction or another.
To offer the best chance for success, we like to be involved early in the program, at the salt selection and pre-formulation stage. The choice of an appropriate salt form can be critical, and the pre-formulation data, such as solubility, hygroscopicity, and stability, may weigh in favor of one dosage form over another. In other cases, the pre-formulation data suggest that more than one dosage form may be feasible, and a parallel path of formulation development and stability characterization may be warranted, looking at two or three dosage forms at once. These paths may converge on one dosage form to promote to preclinical tox or first-in-man studies. Or, in some scenarios, it may make sense to use a nebulized product for early clinical work and switch to an MDI or DPI at a later stage once toxicity and safety are understood. Setting off on the right foot with these early decisions can be critical to the timeliness and ultimate success of a development program.
Contact me if you would like to discuss your specific dosage form selection plan.