A dosage form that delivers several drugs, either at once or in succession, can have many benefits for patients. The administered drugs could have synergistic effects when delivered together, and the convenient dosage form could improve patient compliance. And, of course, reformulating several drugs for codelivery could help breathe new life into a company’s patents. All of these advantages came to mind when I learned about a multiple-compartment gel capsule developed at the Georgia Institute of Technology.
The capsules, which are made of polymeric hydrogels, are hollow except for polymer chains that are linked to the interior of the shell. These chains divide the capsule’s interior into various compartments that could contain several active ingredients. Possible applications include cancer therapy and pain relief.
The researchers formed the capsules in a two-step process. First, they formed chains of a temperature-sensitive polymer without using a cross-linking agent. The absence of this agent causes the chains to dissolve at a certain temperature. Next, the scientists added a cross-linking agent to a second polymer to create a shell around the temperature-sensitive polymer chains. Cooling the microcapsule caused the shell to swell until it reached its stable size, leaving behind temperature-sensitive polymer chains that can act as hydrophobic drug carriers.
The scientists are still trying to determine the best way to load drugs into the capsules and the best way to trigger them to release the drugs. Even though the capsules are still being refined, they have the potential to become a useful drug-delivery tool. Polymeric microspheres, while not new to the drug industry, can be a versatile delivery method. The straightforward process for creating the capsules also could attract drugmakers’ attention. The Georgia Tech team’s work provides cause for optimism at a time when some observers lament the lack of innovation in the drug industry.