Furthermore, medicines that are designed for inhalation also benefit from a rapid onset of action, a reduced risk of systemic side-effects and high and long-term pulmonary efficacy. One dose of inhalable medicine may contain only a fraction of the active ingredient used in a solid dosage due to enhanced bioavailability.

Currently, the global inhalable drugs market is expected to grow at a CAGR of around 6.4% from 2019 to 2026 and projected to reach a value of approximately $41.5 billion by 2026. And although the main applications will continue to be asthma, chronic obstructive pulmonary disease (COPD), lung cancer, bacterial pneumonia, tuberculosis (TB), infectious and other respiratory diseases, the rising prevalence of non-respiratory conditions such as Parkinson’s is also accelerating market growth.

At the same time, it’s widely predicted that the increasing prevalence of various respiratory morbidity and mortality, coupled with an ever-expanding geriatric population, rising air pollution levels and higher levels of urbanization - particularly in Asian mega-cities - will drive growth in the inhalable drug and respiratory devices market. For instance, the World Health Organization recognizes that asthma is of major public health importance and estimates that there are more than 340 million people who suffer from the condition globally.

Recent viral outbreaks that have spread from Asia around the world, TB (with or without HIV) and the antibiotic resistance of bacterial organisms have also contributed to the persistence of respiratory diseases, particularly when socio-economic factors are considered. Even COVID-19 has fallen within the realm of inhaled therapeutics, with one company working on two specific medicines with antiviral properties that can be inhaled directly into the respiratory tract, and another developing a nasal spray that has been shown to reduce the risk of infection by 78% when used ahead of a public gathering.

Manufacturing spray powders and liquids for inhalation

Developing an inhalation product involves multiple disciplines, including device, particle and formulation technologies, aerosol and manufacturing sciences, as well as regulatory expertise. The use of new approaches, subsequent product lifecycle management and working closely with regulatory agents will likely become routine in the inhalation industry, ultimately bringing more quality products to patients.   

Fine powders: Producing powders for inhalation is relatively easy on a small scale; but it can be hard to replicate at the commercial level. To facilitate the process, GEA has developed a highly specialized spray drying system that offers large-scale particle engineering capabilities. This makes it possible to accurately manipulate the aerodynamic size and flow properties of particles to produce fine, free-flowing powders for applications such as commercializing biological compounds including hormones, peptides and proteins that risk degradation if ingested.

When it comes to mixing and blending, GEA understands that homogeneity and stability are key factors during the production of inhalable drugs. GEA also offers production-scale mixing and blending solutions to produce inhalable products (dry powders and suspensions). The TRV high-speed blender, a standalone PharmaConnect^® module, is particularly suitable for the rapid batch blending of small quantities of APIs with base excipients.  

Inhalable liquids: For liquid dosage forms, size matters! Using GEA technology to reduce the particle size, any fluid dispersion or emulsion - in a wide range of viscosities - can be micronized under aseptic conditions using cGMP-validated high-pressure homogenizers. This makes the API dispersion more stable for enhanced clinical effectiveness.

To ensure that liquid inhalables and aerosols get to where they should - the oral cavity or the greater respiratory system - GEA puts a lot of effort into the design and layout of appropriate plant, no matter how big or small.

Looking ahead

With advancements in the use of nanocrystals, surfactant carriers and micro and various nanoparticles, as well as the application of small molecules, it’s clear that progress in the inhalation field continues apace. Many of the new active ingredients under development, for example, target applications that range from oncology to CNS, endocrinology, cardiovascular and beyond. Therapeutics outside of the respiratory space that are already benefiting from this delivery method include peptides and proteins, vaccines and, more recently, RNA based treatments, as well as some pain relievers. 

In terms of drug delivery, the device space has moved beyond traditional metered dose and dry powder inhalers and now includes nebulizers, liquid and soft mist inhalers, as well as propellant-free varieties that offer better delivery efficiency and greater compatibility with labile molecules.

The emergence of new device technology, improvements in container closure systems, new excipients and advances in particle engineering technology all bring significant developments in efficiency and clinical efficacy. Bioavailability and solubility issues are being addressed; there’s an increased focus on combined drug and device development and a huge drive to improve and enhance the patient experience.