Program of Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
Int J Pharm. 2012 Sep 15;434(1-2):360-5. doi: 10.1016/j.ijpharm.2012.06.017. Epub 2012 Jun 12.
Among thymol, carvacrol, citronellal, eugenol and terpinen-4-ol, thymol showed the highest antibacterial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Thymol was then encapsulated into water dispersible submicron sized ethylcellulose/methylcellulose spheres, attaining the relatively high thymol loading level of 43.53% (weight of encapsulated thymol to weight of the thymol-loaded spheres). When tested against the same three bacterial strains, the encapsulated thymol gave comparable minimal inhibition concentration (MIC) and minimal bactericidal concentration (MBC) values to the unencapsulated compound while mostly showing lower MIC and MBC values than the conventionally used preservative, methyl-p-hydroxybenzoate (methylparaben). The use of encapsulated thymol at 0.078, 0.156 and 0.625 mg ml(-1) (0.52, 1.04 and 4.16 mmol(-1), respectively) in cosmetic lotion formulations provided total suppression of viable E. coli, S. aureus and P. aeruginosa growth (all initially seeded at 10(5) cfu ml(-1)), respectively, over the three month test period, whereas unencapsulated thymol showed effective suppression for only 2-4 weeks. Effective bacterial suppression by encapsulated thymol was also observed when used in cream and aqueous gel cosmetic formulations.
在百里酚、香芹酚、香茅醛、丁子香酚和萜品-4-醇中，百里酚对金黄色葡萄球菌、大肠杆菌和铜绿假单胞菌表现出最高的抗菌活性。然后将百里酚包封到水可分散的亚微米级乙基纤维素/甲基纤维素球中，达到相对较高的 43.53%（包封百里酚的重量与载有百里酚的球的重量之比）的百里酚负载水平。在测试对相同的三种细菌菌株时，包封的百里酚与未包封的化合物表现出可比的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）值，而大多数情况下显示出比常规使用的防腐剂对羟基苯甲酸甲酯（对羟基苯甲酸甲酯）更低的 MIC 和 MBC 值。在化妆品乳液制剂中使用 0.078、0.156 和 0.625mgml(-1)（0.52、1.04 和 4.16mmol(-1)，分别）的包封百里酚分别在三个月的测试期内完全抑制了活大肠杆菌、金黄色葡萄球菌和铜绿假单胞菌的生长（初始接种量均为 10(5)cfuml(-1)），而未包封的百里酚仅有效抑制了 2-4 周。在乳膏和水性凝胶化妆品制剂中使用包封的百里酚也观察到了有效的细菌抑制作用。
