ABSTRACT According to the Global Burden of Disease (GBD) estimates, mosquito‐borne and neglected tropical diseases accounted for a substantial global health burden, contributing to over 700,000 deaths and more than 50 million DALYs in 1990, which declined by 2023 to approximately 400,000–600,000 deaths with a corresponding reduction in DALYs. This emphasized the need for sustained vector control strategies, and the development of mosquito repellents, which has steadily progressed through successive stages over time. Chemical‐based repellents were subsequently replaced by plant‐based products and essential oils. Specifically, citronella oil (CO) gained significant attention due to its effective spatial repellency during camping. CO is a volatile substance that readily evaporates, which limits its effectiveness as a mosquito repellent. One of the most effective approaches to accomplish enhanced stability and controlled release of CO is by applying microencapsulation technology. Microencapsulation is the process of enclosing microscopic liquid droplets or tiny solid particles with thin polymeric coating(s). Coating polymers influence the release pattern of CO from the microcapsule. Controlled release of CO by microencapsulation appears to be the most efficient way to protect it from environmental degradation and hence provide a longer shelf‐life, demonstrating its prolonged mosquito repellent ability. It also offers high loading capacity and encapsulation efficiency ranging from 30% to 100%. This article is a review of microencapsulation of CO, including chronological development of mosquito repellents and the necessity for microencapsulation systems. We also cover conventional and emerging methods and technologies, loading and encapsulation efficiency, permeation and release patterns, as well as the limitations and applications of microencapsulation of CO, with special emphasis on its mosquito repellent activity in both solution form and as coatings and treatments of fabrics.
Kamal et al. (Mon,) studied this question.