Impact of skin/core architecture on drug release from extruded and injection molded long-acting implants and tablets

Principal investigator: Anne Gohn

University: Penn State Behrend

Industry partner: Merck & Co., Inc.

Controlled drug delivery in long-acting implants is an innovative topic in pharmaceutical manufacturing. In a first engagement between Merck Pharmaceuticals and Penn State Behrend’s Plastics Engineering Technology department, the Pennsylvania Department of Community and Economic Development funded a 2019 proposal to study the effects of extrusion versus injection molding manufacturing techniques on surrogate active pharmaceutical ingredient release over time. Polymer material and drug properties (i.e., particle size, shape, content) were also studied as a function of these manufacturing techniques. This first research endeavor proved to be a successful collaboration yielding critical information about release kinetics as related to real-life manufacturing considerations. In this follow-up proposal, the researchers intend to take manufacturing to a more advanced level by creating a tailored drug release profile to mitigate patient safety concerns.

The objective of the current proposal is to introduce a porous polymer skin/coating on the long-term drug release implant to slow the “burst release” or immediate drug uptake when implanted in the patient. By using co-extrusion and over-molding techniques, a shell can be engineered to coat the implant to slow the release of the drug over time. Penn State Behrend’s niche Plastics Engineering Laboratory gives Merck access to specialized plastics manufacturing equipment to test lab-scale demonstrations of their implant formulations at process-relevant manufacturing conditions. While we expect that this technology can be applied to Merck’s current product lines for contraceptive devices and HIV medication delivery, it may also yield new possibilities for drug-release implants in future medical applications.