Calcium carbonate in drug delivery: functional carrier design, applications, and data-driven perspectives

INTRODUCTION: Calcium carbonate particles are a very potent type of inorganic drug delivery carriers, which have attractive pH responsiveness, strong mechanical properties, and a relatively high loading capacity. Adding organic constituents, like hydrogels, to calcium carbonate particles results in hybrid carriers, where the size, loading capacity, and release profiles can be controlled with higher precision. AREAS COVERED: This review summarizes recent progress in inorganic and hybrid CaCO₃ carriers, highlighting their potential for sustainable and targeted delivery including different methods of synthesis, analyzing loading and release as well as application of machine learning predictive capabilities to design the most desired polymorph: vaterite. Applications cover not only traditional and very extensive field of biomedicine but also delivery to plants in agriculture. EXPERT OPINION: Calcium carbonate, especially vaterite, offers a tunable, biocompatible platform for controlled and sustainable delivery. Hybrid CaCO₃-hydrogel systems address the limits of purely inorganic or organic carriers. Machine learning and explainable AI will accelerate synthesis and formulation optimization. Future progress depends on scalable, eco-friendly production and clear regulatory frameworks.