The lungs are one of the most complicated organs in the body. Therefore, there are several considerations that come into play when formulating a new inhaled drug. “I don’t think I would be exaggerating if I [said] that [the] lungs are probably one of the most complex organs in the body,” said Vivek Gupta, PhD, associate professor, Pharmaceutical Sciences, College of Pharmacy & Health Sciences, St. John’s University, in 

1). “We are talking about multiple branching going from trachea to brochi, and … millions of air sacs, where most of the blood gas exchange happens, [and] where the lungs will give oxygen into the blood for circulation all over the body.”

Because the trachea branches off, the delivery pathway decreases. Therefore, according to Evonne Brennan, consultant at Evonne Brennan Consulting, “To reach its region of impact, a precise micronized dose of drug substance will need to be delivered in an aerosolized state, through the aid of a device and a formulation designed for delivery from that device, through simple actuation or a synchronized undertaking by the patient, the aerosolized particles travel with the patient’s airflow through a series of pathways where it is deposited.”

Obstacles caused by disease could restrict delivery further and cause increased mucus, remarks Brennan. “Deposition of the drug substance is required to deliver its pharmacological response,” Brennan stresses. Other complications for delivery of drug substance via inhalation can be caused by age, post-reflux cough, and patient compliance.

“For a given indication and drug substance, there are many physiological factors that need to be considered during product development for inhalation, such as patient pulmonary function, clearance mechanisms, etc., and these are addressed in an integrated way at the formulation and device development levels,” says Eunice Costa, R&D director–Inhalation and Advanced Drug Delivery, Hovione.

Attributes such as formulation particle size and density and inhaler dispersion performance need to be controlled to ensure successful deposit of the product into the lungs, according to Costa. “Once deposited, bioavailability of the drug becomes a function of additional factors such as intrinsic chemical properties as well as solid state and formulation composition, being that dissolution and/or permeation needs to occur at a faster rate than the clearance mechanisms in place in the local diseased microenvironment,” Costa says.

When referring to this article, please cite it as Haigney, S. Formulating Inhaled Medicines. 

Pharmaceutical Technology Trends in Formulation 

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Formulation

Formulating Inhaled Medicines

There are a variety of factors pushing innovation in formulation of drug products forward. The desire to create new delivery methods for biologics, the need to increase patient adherence, and technologies such as artificial intelligence (AI) are some of the trends drug developers in the industry are cultivating.

According to Sibaji Biswas, executive director and chief financial officer at Syngene International, patient-centric approaches have led to formulation strategies being reshaped, especially for biologics, with compounds for low solubility and oral bioavailability in small-molecule drugs continuing to see growth. “This has increased demand for solubility and bioavailability enhancement technologies, with CDMOs [contract development and manufacturing organizations] now needing more comprehensive capabilities so they can take a ‘fit-for-purpose’ approach to any challenge,” says Biswas. “Solid dispersion technology and other solubility enhancement methods are gaining prominence, while AI and machine learning [ML] are helping transform pharmaceutical formulation by predicting properties and behaviors.”

The use of ML and AI has been increasing in the bio/pharmaceutical industry. For formulation, they are being used to enhance modeling and predictive approaches, according to Shahrzad Missaghi, senior manager of Product Development, at Colorcon.

ML and AI allow for rapid innovation, according to Asma Patel, VP, Integrated Development Services, Quotient Sciences, as long as members of the industry are open to using these technologies. “From a discovery perspective, this can continue to fuel complexity in small new chemical and new molecular entities (NCEs/NMEs). Regardless of AI/ML, NCEs/NMEs continue to see an increase in average molecular weights and generation of new classes such as PROTACs [Proteolysis targeting chimeras], both creating solubility challenges for pharmaceutical formulation,” says Patel.

Vincent Levet, PhD, director, Formulation Development and Production, Ardena, agrees. “[AI] is showing great potential to revolutionize formulation development, from supporting excipient selection to predicting outcomes and optimizing processes.”

Additional formulation trends include delivery through lipid nanoparticles, ultra-high protein concentration formulations, continuous manufacturing, automation, and the creation of orphan drugs.

Automation has had a significant impact on the development of medicines delivered in capsule and tablet forms, according to Vinay Patil, Product Development Manager at Sharp Services. “Modern machines offer high-speed, precision filling and can handle various fill materials such as powders, granules, pellets, and even liquids,” says Patil. “Even more currently, micro-dosing technology allows us to accurately dose small quantities of API, which is critical when working with potent drugs. These advancements have increased the speed and precision of drug production and expanded the range of materials that can be used.” Patil also points to advances in granulation, compression, and coating that have impacted formulation.

“The introduction of high-shear granulators, fluid-bed processors, and roller compaction has enhanced the production of tablets with better mechanical properties and dissolution profiles. Coating technologies have also advanced, with enteric coatings and controlled-release formulations becoming more common,” says Patil. “Recently, continuous manufacturing processes have improved tablet production efficiency, allowing for real-time monitoring and increased production speed. One very recent advancement is the use of 3D printing technology, which has allowed for the production of tablets with controlled release profiles personalized to individual patients.”

®
eBook: Trends in Formulation 2024
September 2024
Pages: 34–37

When referring to this article, please cite it as Haigney, S. Forging Ahead in Formulation. 

Pharmaceutical Technology®/Pharmaceutical Technology EuropeTM

New and existing technologies, as well as a patient-centric focus, are pushing drug formulation into exciting directions.

Trends in Formulation, September 2024 eBook

Formulating Inhaled Medicines

Forging Ahead in Formulation