A novel, multi-channelled microfluidic system to approach burst-free and long-term drug delivery

Long-term drug delivery systems are an attractive option to drug manufacturers and patients alike due to simplified dosing schedules and reduced negative side effects which increase patient therapy compliance and quality of life. Being studied for decades, multiple controlled release systems have been developed to sustain the release of target therapeutic agents; however, these methods have various drawbacks such as difficulty in formulation, high cost, etc. that limit widespread commercial usage. One pervasive challenge in these solutions is the burst release phenomena-where an uncontrolled bolus of drug is released immediately upon product usage which lowers the effective lifetime of the drug or medical device. While methods have been developed to address burst release in sustained release systems, these methods often require extra processing steps that waste a portion of the initially loaded drug or may leave the device prone to failure if not processed correctly. To address this issue, a microfluidic release system was developed using a novel method of rapidly, tunably, and cost effectively creating microchannels bundles without the use of non-biocompatible materials. In this study, we investigated the sustained release of both a model small molecule and model large molecule from these novel microchannel bundles of varying channel diameters. From this, we discovered that rate of release was tunably controlled by modifying microchannel diameters in these bundles, significantly extending the product lifetime at increasingly thin channel diameters. Additionally, burst release was decreased by tunably lowering microchannel diameters within the bundle. As a result, this study provides a novel method of creating microfluidic drug delivery systems that could address major issues in current sustained release drug delivery systems.