Multifunctional composite capsules in drug delivery systems: bridging pharmaceutical and biomedical applications

Abstract

Chronic diseases such as cancer and diabetes demand advanced drug delivery methods that can accommodate precise, sustained, and targeted release of active compounds. Existing drug carriers such as conventional capsules are limited by issues like poor bioavailability, mechanical fragility, and unpredictable release patterns. With the global drug delivery market expected to surpass USD 1.8 trillion by 2028, it is crucial to address these challenges. Additionally, there is a growing need to develop biocompatible systems that can mitigate concerns about toxicity, environmental impact, and patient compliance. Here, we review the latest advancements in composite drug capsules, focusing on key aspects such as controlled drug release, mechanical properties, biocompatibility, and antimicrobial potential. Composite materials offer customised release mechanisms by combining synthetic and natural polymers. This has led to improvements in stability, encapsulation efficiency, and bioavailability. Some noteworthy advancements in this field include the development of magnetic-responsive systems for targeted therapies, alginate-based dual-release systems, and solid lipid nanoparticles (SLNs) for gene delivery. For example, the encapsulation of lycopene in whey protein composites achieved an impressive encapsulation efficiency of 94%, showcasing enhanced delivery performance. Additionally, there have been developments in pH-sensitive capsules designed for cancer treatment, which release drugs selectively in tumour environments. Furthermore, multifunctional magnetic capsules have been created to facilitate MRI imaging and remote-controlled drug release. Moreover, pH-sensitive alginate-based capsules have proven effective in improving the therapeutic outcomes of cancer treatments by ensuring drug release specifically within the acidic tumour microenvironment. Other notable achievements include the integration of antioxidant nanoparticles, such as cerium oxide (CeO₂), into drug delivery systems, showing potential for mitigating oxidative stress and providing neuroprotection in inflammatory and neurodegenerative conditions. Despite these innovations, persistent challenges related to scalability, regulatory clearance, and enduring biocompatibility necessitate further investigation. These combined capsules possess significant potential, presenting more intelligent, adaptable drug delivery systems positioned to transform personalised medicine and future healthcare solutions.