The Role of Micronization With Dry Powder Inhaler Technologies
As early as the 2021 United Nations climate change conference (COP26) ended in Glasgow, the World Health Organization reports that an estimated 9 out of 10 people worldwide are affected by high levels of air pollution.
Millions of people suffer from asthma, the most common chronic disease in childhood, around 65 million people suffer from chronic obstructive pulmonary disease (COPD) of which 3 million people die each year, making it the third leading cause of death worldwide.
Situation in China
Let’s have a closer look to China. Chronic obstructive pulmonary disease (COPD) there is widespread with 8.6 percent of the country's adult population - almost 100 million people - suffering from this chronic lung disease.1
According to the Global Initiative for Asthma, there are more than 500 million asthma patients worldwide, with over 30 million in China. This number increases by 4% annually.
How to treat asthma?
Most asthma medications are inhaled. With an inhaler (or nebulizer) the medicine goes straight into the lungs. Some drugs are also available in tablet, infusion or injectable form.
A specially designed truck sprays mist to reduce dust in the air in Zhengzhou, Henan province. Yang Zhenghua / China Daily
There are four types of asthma inhaler devices that deliver medicine: nebulizers, metered dose inhalers (MDI), dry powder inhalers (DPI), breath actuated inhalers and soft mist inhalers (SMI)
Dry Powder Inhalers (DPIs) have many unique advantages that have contributed to the incredible growth of DPI pharmaceutical products. A relatively large number of DPI devices for various inhalable powder formulations are available to increase performance.
DPI and Micronization
The Aerosol Society (aerosol-soc.com) has carried out a study that shows that the inhalation performance of a dry powder inhaler (DPI) is strictly correlated with the critical quality attributes (CQA) of the active pharmaceutical ingredient (API). Particles typically need to be reduced in size within the aerodynamic diameter range of 1-5 µm in order to reach the airways. These dimensions are usually targeted when micronizing crystalline API. Jet mills are a widespread micronization technology, through which micronization is achieved by using air or nitrogen at very high pressure.
The two most important critical process parameters (CPP) which directly affect the API particle size are micronizing pressure and feed rate. Nowadays it is of fundamental importance for a manufacturer to rely on a technology able to achieve the desired DPI inhalation performance through direct control of the micronizing parameters.
The Dec Solution for DPI Manufacturers
Achieving high performance with conventional jet mills remains very difficult, therefore, Dec has set itself the task to develop, in close cooperation with global pharmaceutical partners, a new generation of spiral jet mills meeting specific particle size distribution (PSD) targets. Significant improvement has been achieved with the help of Computational Fluid Dynamic modelling carried out to study the mill performance at diverse operating parameters. The effort was worth it, the new patented 4th generation MC DecJet® range of spiral jet mills is now able to micronize corticosteroids such as fluticasone while maintaining a very tight PSD curve with a typical measurement of d50 < 2 µm, representing a 50% improvement in terms of cumulative distribution and impeccable scalability from research to production models.
MC DecJet® jet mills enable to obtain a very tight controllable Gauss curve and high recovery yields.
Computational simulation of the gas injection inside the micronization chamber
This ensures effective drug deposition deep into the small peripheral airways of the lungs. The carved chamber version with low-friction inserts is part of the success.
The global interest in developing improved therapies for pulmonary and other diseases leads to a significant increase in the use of highly potent active pharmaceutical ingredients (HPAPIs). In chronic obstructive pulmonary disease, higher potency drugs typically have the potential to achieve similar or better efficacy than other drugs at a lower dose. These powerful substances require a hazard and risk-based approach in ensuring safe handling methods and high containment.
The most common methods for classifying highly potent active ingredients are based on control banding strategies, which categorize APIs based on occupational exposure limits. An occupational exposure limit (OEL) is an upper limit for the acceptable concentration of an active substance in the air at the workplace. Therefore, drug manufacturers not only place extremely high demands on micronization performance, but also on containment strategies and high dosing accuracy.
Focus on Containment
Dec’s micronizing isolators provide a safe enclosure around the micronization process and therefore high containment of potent and/or sterile compounds thus offering both operator and product protection. The MC DecJet® micronizing and containment range (from MC DecJet® 30 to MC DecJet® 400) is the perfect union of years of experience as user and provider of micronizing and containment technologies. Dec can offer highly complex integrated and completely contained solutions from the handling of the incoming powders, to micronization and micro-dosing within the isolator resulting in perfect inhaler filling operations.
MC150 Micronizing and Dispensing Isolator
Years of experience and deep-rooted expertise have made Dec a world leader in both micronization and process containment technologies also able to provide technical customer support for their process development and optimization.
With a large number of solutions for particle size reduction implemented all around the world, of which DPI production is becoming increasingly important, Dec is helping to improve life with asthma thanks to its highly contained concepts allowing to achieve the desired DPI inhalation performance through the control of the particle size reduction process parameters.
1 Source: Tulane University study published in The Lancet.