Microencapsulation of Herbal and Natural Products for Therapeutic Delivery: A Review

Abstract

Microencapsulation has emerged as a pivotal drug delivery technology that enhances the therapeutic potential of natural-based drugs by improving their stability, solubility, bioavailability, and controlled release. This review critically examines the principles, techniques, materials, and applications of microencapsulation in the context of herbal and plant-derived pharmaceuticals. Herbal drugs—despite their long-standing traditional use—often face clinical limitations due to poor water solubility, rapid degradation, and low systemic absorption. Microencapsulation offers a feasible solution by enclosing bioactives within biocompatible polymers such as chitosan, alginate, poly (lactic-co-glycolic acid), and gelatin, protecting them from environmental degradation and facilitating targeted delivery. The review explores major microencapsulation techniques, including spray drying, coacervation, ionic gelation, and liposomal entrapment, and highlights their advantages, limitations, and suitability for different compound types. Curcumin, quercetin, resveratrol, and essential oils underscore the efficacy of microencapsulation in enhancing pharmacokinetics and therapeutic performance. Furthermore, this work identifies critical gaps in the current literature—such as limited focus on synergistic plant combinations, and challenges in regulatory standardization. The future direction emphasizes sustainable microencapsulating agents, scalability, and interdisciplinary research integrating ethnopharmacology and advanced material science.