Curcumin Delivery Systems: How Far from Clinical Application in Tumor Therapy?

Curcumin, a natural polyphenol compound found in turmeric, exhibits significant anti-cancer activity in preclinical studies. However, its clinical application is limited by poor bioavailability and low solubility in aqueous media. To overcome these challenges, various curcumin delivery systems (CDSs) have been developed to enhance the pharmacokinetics and pharmacodynamics of curcumin, aiming to improve its solubility, stability, and targeted delivery to tumor cells. Preclinical studies have shown that CDSs can improve pharmacokinetics, enhance anti-tumor efficacy, and reduce toxicity in various cancers. Several CDSs have also advanced into clinical trials, demonstrating safety and efficacy in cancer patients. Despite the promising results, challenges remain, such as optimizing formulation and dosage, investigating curcumin's influence on the carriers in drug delivery and release, evaluating long-term safety and toxicity, and conducting large-scale clinical trials. Understanding the effect of gut microbiota on CDSs metabolism and bioavailability is critical for enhancing their clinical effectiveness in tumor therapy. Further research and development are necessary to fully exploit the potential of CDSs in cancer treatment. This review summarizes recent progress in CDSs research and their potential application in tumor therapy, encompassing formulation strategies, delivery routes, as well as preclinical and clinical evaluations. It not only provides valuable insights into the future rational design and development of curcumin dosage forms and their cancer therapeutic potential but also facilitates the clinical translation of curcumin and CDSs.