Ultralong floating hydrogel raft for prolonged gastric retention

Abstract: The optimal therapeutic efficiency of any treatment depends on patient adherence to the medication regimen. Medication adherence is the cornerstone of treatment outcomes that may consequently impact economic and healthcare costs. With the oral route being the preferred route of drug administration, slow or extended-release oral formulations can, therefore, be utilized. Here, a biocompatible oral delivery system that can be retained in the stomach for a week, while providing continuous release of the encased drug, is proposed. The fabrication of the delivery system was achieved using a simple mold casting technique. The hydrogel-based raft was able to float under simulated gastric conditions for seven days with pH switches to mimic the fasted and fed states of the stomach. The functionality of such a delivery system has been exemplified using two different model drugs—risperidone and metoprolol tartrate of varied solubilities and has been shown to effectively sustain the release of drugs under the tested conditions. Impact statement: An oral delivery system is proposed to tackle the soaring problem of medication nonadherence predominantly for conditions that require long-term medication. The proposed delivery system is designed to float in the stomach, thereby prolonging gastric retention and sustaining drug release for more than a week. Subsequently, once drug release is completed, it can be dissolved away using an extrinsic trigger. Any chronic disease condition that requires multiple dosing per day or to be taken over a prolonged period would benefit from such a sustained-releasing drug delivery system. This reduces dosing frequency and consequently improves patient medication compliance. The proposed design allows for easy adaptation to different drugs making it customizable to the patient’s needs. The application of the delivery system may also be extended to the delivery and retention of miniature devices, such as glucose sensors that are to be retained for an extended period in the body, for the purpose of health monitoring or probing. In addition, this technology could have an impact beyond biomedical/pharmaceutical applications, where the need for extended release is a requirement. For instance, as a floating device for environmental purposes (i.e., slow release of pesticides into water bodies against mosquito breeding may be a possibility). Graphical abstract: [Figure not available: see fulltext.]