Camptothecin in Cancer Therapy: Current Challenges and Emerging Strategies with Nanoemulsions

Camptothecin (CPT) is a natural alkaloid with potent antiproliferative activity, mediated by the inhibition of Topoisomerase I (Topo I), an essential enzyme for deoxyribonucleic acid (DNA) replication. However, its clinical application has been limited by low solubility and the instability of the lactone ring under physiological conditions, both of which decrease its efficacy. Semi-synthetic analogs such as irinotecan (CPT-11) and topotecan (TPT) have been developed and approved for the treatment of various types of cancer; however, challenges related to drug resistance and side effects continue to arise. Therefore, nanomedicine and nanoparticle-based delivery systems, including nanoemulsions, liposomes, and antibody-drug conjugates (ADCs), emerge as promising strategies to improve the stability, bioavailability, and effectiveness of CPT, despite significant challenges such as scalability, pharmacokinetic variability, and regulatory requirements. This review discusses recent advances in CPT, its analogs, and these delivery platforms, highlighting its potential to optimize cancer therapy and reduce toxicity while outlining translational challenges such as scalability, pharmacokinetic variability, and regulatory requirements.