Due to their larger size and structure, peptide drugs are rarely taken orally and must be injected.Microencapsulation is one way to reduce the time required between injections.(Source: Getty Images)
Microencapsulation in biodegradable polymers allows drugs, such as peptide therapeutics, to be released in the body over time.
Peptides are molecules in the body composed of short chains of amino acids, including messengers, growth factors, and well-known hormones such as insulin.Due to their larger size and structure, peptide drugs are rarely taken orally and must be injected.Microencapsulation is one way to reduce the time required between injections.
Study co-author Steven Schwendeman, a professor of pharmaceutical science and biomedical engineering at the University of Michigan, said one slow-release delivery method for peptide drugs would be to encapsulate them in the type of absorbable polymers commonly used as dissolving sutures.
However, developing polymeric dosage forms for the delivery of certain peptide drugs has been difficult because currently available methods of microencapsulating peptide molecules in polymers require organic solvents and complex fabrication.
“About 10 years ago, Schwendeman’s group discovered that peptides can bind and spontaneously enter polymers from water, making it very simple to microencapsulate peptides without the need for organic solvents,” Schwendeman said.
At the time, the group showed that the concept might work, but it was not yet commercially useful, he said.
“This paper shows that the concept can efficiently make equivalent or even improved injectable biodegradable polymer particles compared to existing commercial products that slowly release several different peptides over a month, providing One of the first completely new methods of microencapsulation in decades,” Schwendemann said.
Schwendeman and colleagues found that if they first made the polymer and equilibrated the peptide with polymer microspheres in water under specific conditions, they could achieve results very similar to traditional organic solvent-based drug encapsulation methods.
In the current study, the researchers found that leuprolide encapsulated in this way released the peptide in the lab for more than 56 days and suppressed testosterone production in rats in the same way as a one-month injection of Lupron Depot.Leuprolide injection is used to treat prostate cancer, endometriosis, and other conditions.
This encapsulation approach works for several other peptide drugs on the market, as well as others that have recently been approved or are in development, Schwendeman said.
The group is now expanding the ability to encapsulate different types of peptides and other macromolecular drugs, delivering drugs over longer periods of time, and developing a second technique to remotely load drugs into polymers, which focuses on fragile proteins .
Post time: Jun-27-2022