Researchers at NYU Tandon School of Engineering have developed a new method for creating microscopic drug delivery capsules that addresses a fundamental challenge in pharmaceutical manufacturing.
The technique, called Sequential NanoPrecipitation (SNaP), tackles the persistent difficulty of producing uniform, precisely sized drug delivery particles at industrial scales. Current methods either provide excellent control but can only make small batches, or can produce large quantities but with less precision, a trade-off that has limited the development of advanced drug delivery systems.
The research, published in ACS Engineering Au , addresses this challenge and represents a significant advance in Nathalie Pinkerton 's ongoing mission to develop universal drug delivery systems. The paper was selected as an ACS Editors' Choice, highlighting articles with potential for broad public interest.
Having previously worked in Pfizer's Oncology Research Unit developing novel nano-medicines for solid tumors, Pinkerton — now an assistant professor in NYU Tandon's Chemical and Biomolecular Engineering (CBE) Department — focuses on creating scalable solutions that can "translate from the lab bench to the patient's bedside."
The new research moves SNaP from a promising proof-of-concept into a predictable manufacturing process by providing the fundamental understanding needed to control particle properties systematically.
"It's like trying to consistently make the perfect cookies," said Pinkerton, the paper's senior author. "You can make a dozen consistent cookies in one small batch in your kitchen, but when you try to make a thousand cookies in one big batch, challenges arise. The dough won't mix right; some cookies burn and others underbake. You need to rethink the process to get the same delicious cookies at a larger scale."
Drug delivery microparticles (capsules about one-thousandth the width of a human hair) are already used in several FDA-approved treatments, including long-acting formulations for opioid addiction, schizophrenia, and heart conditions. These tiny vehicles can encapsulate medications and release them slowly over time, reducing the frequency of injections and improving patient compliance.
The researchers demonstrated precise control over particle sizes ranging from 1.6 to 3.0 micrometers, which they note is ideal for inhalation delivery applications. Size is a key quality attribute that influences how the particles behave in the body and release their medication.
The SNaP process works through carefully orchestrated mixing in millimeter-scale chambers. In the first step, a stream containing dissolved drug and core polymer materials is rapidly mixed with water, causing the materials to precipitate and form tiny cores. In the second step, after a precisely controlled delay time, stabilizing agents are added to stop the growth and lock in the desired size.
"Think of it like using a start-stop timer," said Parker Lewis, the study's lead author and an NYU Tandon PhD candidate. "The first mixer starts particle growth, and the second mixer stops it at a precise size by coating them with a non-stick surface."
By adjusting the delay time between the two mixing steps, measured in milliseconds, the researchers can control how large the particles grow.
What makes SNaP particularly significant is its potential for scalability. Traditional precision methods like microfluidics can only produce small amounts of particles — about 6 grams per hour. Industrial methods like spray drying can produce much larger quantities but with poor size control. SNaP, operating in continuous flow, demonstrated production rates of 144 to 360 grams of microparticles per hour in laboratory conditions, with potential for further scale-up using larger mixing equipment.
The researchers validated their approach by successfully encapsulating itraconazole, an antifungal medication, achieving 83-85% encapsulation efficiency, meaning very little drug was wasted during the process.
The method is particularly valuable for the pharmaceutical industry because it addresses a well-known bottleneck in drug development. Many promising drug delivery concepts fail to reach patients because they cannot be manufactured consistently at commercial scales.
For patients, the ultimate benefit could be more effective medications with fewer side effects, delivered through more convenient treatment schedules. The technology must prove itself in larger-scale testing and eventually in clinical trials, a process that could take several years.
In addition to Pinkerton and Lewis, the paper's authors are Nouha El Amri and Erica E. Burnham from NYU Tandon's CBE Department, and Natalia Arruz from NYU Tandon's Department of Mechanical and Aerospace Engineering .
