INFORM 2020 – Molecules to Manufacture: Processing and Formulation Engineering of Inhalable Nanoaggregates and Microparticles

Lung diseases are a major global health burden. 300 million people live with asthma worldwide and it is predicted that chronic obstructive pulmonary disease will become the third-leading cause of death by 2020. The inhalation of therapeutic aerosols is a familiar medical strategy to treat lung diseases.

When aerosols are targeted into the deep lung, inhaled therapy also provides a means to achieve systemic concentrations of active pharmaceutical ingredients and avoid the need for injections of drugs that are destroyed in the gastrointestinal tract, such as insulin.

Achieving aerosol deposition in the lungs is a major challenge because it is necessary to produce a portable dosage form containing components that can be redispersed by a patient. Redispersion must be achieved with uniformity of a dose in the form of an aerosol with the properties required for lung penetration.

Turning potentially inhalable particles into formulated products that can be manufactured reproducibly, and that achieve consistent aerosolization performance between different patients poses many challenges that are poorly-solved. There is also a need to improve our understanding of how and why the characteristics of starting materials interact with the manufacturing conditions to lead to inter-batch and inter-patient variability in aerosol characteristics. At the heart of the challenge is the fact that the very property of the particles that makes them suitable for inhalation (their small size which, at less than 5 microns, is less than the diameter of a human hair) also causes them to clump together as agglomerates.

Theme 1 of the project will employ synthonic engineering (a computer modelling technique based on the molecular structures of pharmaceutical ingredients) to achieve new abilities to predict agglomeration behaviour early in development, and the interactions of agglomerate materials with inactive ingredients in the formulation.

Theme 2 will use new measurement techniques that image how agglomerates interact with each other in powders to develop an understanding and characterize how the agglomerate phase in a formulation leads to inter-patient or inter-batch variability of product performance.

Theme 3 will underpin the knowledge gained from powder imaging to assess the underlying causes of agglomeration. Better, integrated experimental measurement techniques will be developed to characterize the material properties that regulate the extent and strength of interactions between particles.

Theme 4 focuses on developing new computational models to characterize the behaviour of agglomerated powders during the mechanical processes occurring when a patient breathes through an inhaler, and when powders are processed during manufacturing.

The final component of the project is to integrate the knowledge gained in Themes 1-4 to engineer quality into a range of test products selected by an advisory panel. This will be achieved by using the prediction and measurement techniques to inform formulation scientists, device designers and process engineers of the steps that are appropriate to mitigate the effects of agglomeration on product performance. The ultimate goal is to use the techniques developed to translate the therapeutic benefits for patients using inhaled medicines from molecules to manufactured products.