Cyclodextrin-based poly(pseudo)rotaxanes for controlled release of icaridin

Poly(pseudo)rotaxanes (PPR) are obtained with polymers containing PEG and/or PEO groups and cyclodextrins (CD). They can form reversible gels and may control actives release. PPR were developed with the insect repellent, icaridin (IC), aiming to control its volatilization and reduce drug skin permeation. PPR were obtained with 1, 5 or 10% of CD and polymeric dispersions with 45% of polymer A (PA) and 24% of polymer B (PB). Rheology, mean diameter, polydispersion index and visual changes were evaluated. Formulations presented an average diameter of 18.89 ± 2.30 and 67.73 ± 3.14 nm for PA and PB, respectively. The addition of CD in PB dispersions did not significantly change micelles mean diameter and PdI. However, addition of CD to PA dispersions resulted in turbid aspects, with significantly increase in mean diameter and PdI with G'>G’' in rheology studies. Insoluble PPR were obtained and seems to be promising formulations for topical application.