Misni Norashiqin, Nor Zurainee Mohamed, Ahmad Rohani
Department of Parasitology, Faculty of Medicine, University Malaya, Kuala Lumpur; Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, University Putra Malaysia, Serdang, Selangor, Malaysia.
Department of Parasitology, Faculty of Medicine, University Malaya, Kuala Lumpur, Malaysia.
J Vector Borne Dis. 2017 Jan-Mar;54(1):44-53.
BACKGROUND & OBJECTIVES: Many essential oils have been reported as natural sources of insect repellents; however, due to high volatility, they present low repellent effect. Formulation technique by using microencapsulation enables to control the volatility of essential oil and thereby extends the duration of repellency. In this study, the effectiveness of microencapsulated essential oils of Alpinia galanga, Citrus grandis and C. aurantifolia in the lotion formulations were evaluated against mosquito bites.
Essential oils and N,N-Diethyl-3-methylbenzamide (DEET) were encapsulated by using interfacial pre- cipitation techniques before incorporation into lotion base to form microencapsulated (ME) formulation. The pure essential oil and DEET were also prepared into lotion base to produce non-encapsulated (NE) formulation. All the prepared formulations were assessed for their repellent activity against Culex quinquefasciatus under laboratory condition. Field evaluations also were conducted in three different study sites in Peninsular Malaysia. In addi- tion, Citriodiol® (Mosiquard®) and citronella-based repellents (KAPS®, MozAway® and BioZ Natural®) were also included for comparison.
In laboratory conditions, the ME formulations of the essential oils showed no significant difference with regard to the duration of repellent effect compared to the microencapsulated DEET used at the highest con- centration (20%). It exhibited >98% repellent effect for duration of 4 h (p = 0.06). In the field conditions, these formulations demonstrated comparable repellent effect (100% for a duration of 3 h) to Citriodiol® based repellent (Mosiguard®) (p = 0.07). In both test conditions, the ME formulations of the essential oils presented longer duration of 100% repellent effect (between 1 and 2 h) compared to NE formulations.
INTERPRETATION & CONCLUSION: The findings of the study demonstrate that the application of the microencapsulation technique during the preparation of the formulations significantly increases the duration of the repellent effect of the essential oils, suggesting that the ME formulation of essential oils have potential to be commercialized as an alternative plant-based repellent in the market against the mosquitoes.
许多精油已被报道为天然驱虫剂来源；然而，由于挥发性高，它们的驱避效果较低。采用微囊化的制剂技术能够控制精油的挥发性，从而延长驱避持续时间。在本研究中，评估了高良姜、柚和酸橙微囊化精油在乳液制剂中对蚊虫叮咬的有效性。
采用界面沉淀技术将精油和N，N - 二乙基 - 3 - 甲基苯甲酰胺（避蚊胺）进行微囊化，然后加入乳液基质中形成微囊化（ME）制剂。纯精油和避蚊胺也制成乳液基质以制备未微囊化（NE）制剂。在实验室条件下评估所有制备的制剂对致倦库蚊的驱避活性。还在马来西亚半岛的三个不同研究地点进行了现场评估。此外，还纳入了Citriodiol®（Mosiquard®）和香茅基驱虫剂（KAPS®、MozAway®和BioZ Natural®）进行比较。
在实验室条件下，与使用最高浓度（20%）的微囊化避蚊胺相比，精油的ME制剂在驱避效果持续时间方面无显著差异。其在4小时内表现出>98%的驱避效果（p = 0.06）。在现场条件下，这些制剂表现出与基于Citriodiol®的驱虫剂（Mosiguard®）相当的驱避效果（3小时内100%）（p = 0.07）。在两种测试条件下，与NE制剂相比，精油的ME制剂呈现出更长的100%驱避效果持续时间（1至2小时）。
该研究结果表明，在制剂制备过程中应用微囊化技术可显著延长精油的驱避效果持续时间，这表明精油的ME制剂有潜力作为市场上一种替代的植物源驱虫剂商业化，用于对抗蚊虫。
