Imagine a medicine that is effective against a target for a particular disease can’t be formulated in a way that the body can actually use it. A common problem in drug research is when a medicine won’t dissolve in water, for example, and, therefore, cannot be absorbed by the body. That might even lead scientists to abandon these potent compounds and move onto the next drug candidate.
Melt Extrusion (Meltrex) to the Rescue
Used by the plastics industry, among others, researchers wondered if melt extrusion, or Meltrex, could also be applied to these difficult-to-formulate drug candidates. With some adaptation, the answer, it turns out, is “yes.”
Melt extrusion techniques have been around for centuries, and have been broadly applied in industrial settings since the 1930s.
To make plastic products, the technique involves exposing resin and other materials to very hot temperatures so that they melt. Then, the melted plastic is forced into forms. Eventually, they take the shape of milk jugs, or food storage containers, or any number of other plastic products.
In the formulation of medicines, the same idea applies. The active drug substance, which can’t be dissolved in the body, is pre-dissolved in a melted polymer substance, where the active drug spreads out evenly and consistently.
The active drug takes the form of a so-called solid solution, which can then be ground down and combined with other non-active ingredients and ultimately transformed into its final form, such as a tablet or capsule.
“We began applying Meltrex to our work more than 20 years ago, and through adaptations we’ve made over the years, we have turned a processing technology into a drug-delivery technology that enables challenging active drugs to become medicines that are available to the body,” says Bernd Liepold, Ph.D., senior principal research scientist in AbbVie’s drug product development group, based in Ludwigshafen, Germany. “Meltrex is an important tool that continues to open up possibilities for the formulation of new drugs to treat patients with a variety of diseases, from viral infections to cancer.”