Inclusion complexation with cyclodextrins is an effective way to improve stability and turn liquid materials into re-dispersible and easy-to-handle powders. In the present work, the complexation of L gracilis essential oil, already recognized as a potent larvicide material, with hydroxylpropyl-beta-cyclodextrin was performed using Slurry and paste procedures and the complexes obtained were evaluated. The gas chromatography coupled to mass spectrometry (GC/MS) analysis showed a total volatile content of 99.24% in the L. gracilis oil. The characterization of the complex involved the analysis of the original essential oil, the surface, and the total extracted oils. The major components in L gracilis essential oil were identified as carvacrol (23.52%), p-cymene (15.82%), gamma-terpinene (14.17%), and thymol (7.27%). GC/MS results showed significant differences between the original oil, the slurry, and paste complexation. Thermal characterization indicates the Occurrence of complexation, mainly in paste complexes, which presents a TG-DTA peak at 230-275 degrees C, probably related to oil loss. (C) 2008 Elsevier B.V. All rights reserved.