Polymeric microparticles for local treatment of cutaneous leishmaniasis: a comparison of drug delivery systems and unmet clinical needs

INTRODUCTION: Cutaneous leishmaniasis (CL) remains a significant therapeutic challenge, particularly in New World settings, where current local treatments are limited by pain, repeated administration, poor drug penetration, species-dependent efficacy, and systemic toxicity. There is an unmet need for short, safe, effective, and field-adapted therapies. AREAS COVERED: This article reviews current local treatment strategies for CL and examines advances in drug-delivery systems, with particular emphasis on polymeric microparticles. Attention is given to biodegradable PLGA microparticles as long-acting intralesional depots. Preclinical evidence and clinical data are evaluated alongside key barriers to implementation. EXPERT OPINION: Polymeric microparticles, especially PLGA-based depots, represent a promising strategy to modernize local CL treatment by sustaining therapeutic drug concentrations at the lesion while minimizing systemic exposure and reducing dosing frequency. Future development should prioritize species-specific clinical trials, standardized outcomes, pharmacokinetic-pharmacodynamic optimization, patient-centered measures, cost-effectiveness, and particularly scalable manufacturing. If current translational efforts are successful, single-dose therapies could become a realistic component of CL management within the next few years.