Recent advances and future directions of propolis delivery.

Introduction: Propolis is a gum-resinous compound produced by bees for hive protection. It displays complex chemical composition, dependent on the plant sources, and important biological activities, contributing to a wide range of pharmacological effects (e.g. antimicrobial, anti-inflammatory, healing and immunostimulant). Propolis shows poor aqueous solubility and low bioavailability. Thus, delivery systems have been proposed for the administration of propolis by different routes like oral, buccal, topical, local, vaginal, transmucosal, nasal, endodontics and intra-periodontal pocket.

Areas covered: From extracts and ointments, formulations for propolis delivery improved their physicochemical properties. The use of biocompatible, biodegradable, environmentally responsive materials, nanotechnology, and propolis by-product resulted in smart systems: films, micro/nanoparticles, lipid systems, carbon nanotubes, emulsion, and self-emulsifying systems, bioadhesive and environmentally responsive systems, microneedles, liquid crystals, sensors and electrospun fibers.

Expert opinion: Ensuring the efficacy and safety of propolis requires characterization, standardization, and quality control. Challenges like composition variability, limited bioavailability, and inconsistent extraction hinder its optimal use. Nanotechnology improves bioavailability and controlled release, while emerging strategies like microneedles and 3D/4D printing enhance precision and versatility. By integrating nanotechnology and additive manufacturing, researchers can develop safer, more effective delivery systems, expanding propolis applications and fostering innovation in pharmaceutical and biomedical fields.