Controlled delivery formulations remain one of the favored tools for advancing the lifecycle of pharmaceutical products, and excipient selection is vitally important. A traditional strategy is to initially launch multiple daily doses of an immediate-release (IR) product, then reformulate into a once-daily modified-release product, simplifying dosing regimens while retaining efficacy and potentially improving its safety profile.

Further, excipients have become major research components in the pharmaceutical industry. Controlled release excipients give the formulator the ability to carry APIs to a targeted location in the body. This benefit increases the product’s bioavailability and minimizes side effects. With the correct excipient, formulators can control when, where, and how an API is released.

Excipient Selection Challenges

Given the lack of an approval pathway, many drug developers are hesitant to take on the responsibility of toxicology and clinical trials with a untested materials, which may run risk jeopardizing approval of their new drug applications. Additionally, for certain patient populations, excipient choices are somewhat limited. However, there has been a growth in excipient suppliers developing novel excipients that may provide solutions and support to move existing formulations into new areas.

Rational Excipient Selection & Collaboration

Many new excipients are modifications or combinations of previously approved excipients. Excipient selection for the formulation for an immediate release tablet is typically guided by a number of critical attributes of the active ingredient, including concentration, compactability, and solubility.

Excipient manufacturers are working closer with drug product manufacturers as early as possible in the drug product development process in order to not only identify the issues, but to mitigate the impact of the issues proactively. The most successful controlled release formulation approaches have been where excipient suppliers have worked side-by-side with drug developers to understand their specific needs, and, over time, have developed new solutions to meet controlled release formulation challenges as they have arisen.