Chamomile oil loaded solid lipid nanoparticles: A naturally formulated remedy to enhance the wound healing

Chamomile oil (CM) has a crucial effect in promoting wound healing, but its poor tissue permeability and degradation limit its topical application. The aim of the present study is to ameliorate CM healing effect by encapsulating it into solid lipid nanoparticles (SLN). SLN were prepared by hot homogenization method using 20%w/w stearic acid and CM. The in-vivo study involved 40 rats divided into 5 groups. Group I: was normal control, Group II: represented wounded rats without treatment and Groups III to V: were wounded rats treated with plain SLN, CM cream (Camisan (R)) and CM-SLN, respectively. Morphological examination of CM loaded SLN revealed irregular shaped particles with an outer chamomile oil shell surrounding the lipid core. Optimized CM-SLN formed of stearic acid and CM (in ratio 7: 3) had particle size of 542.1 +/- 27.51 nm and zeta potential of -35.9 +/- 0.602 mV with acceptable viscosity and occlusive properties. Topical administration of CM-SLN showed improvement in restoring the normal integument architecture, wound contraction, transforming growth factor-beta 1 and collagen deposition, in addition to the reduction in the Interleulin-1 beta and metalloproteinases-9/tissue inhibitor metalloproteinase-1 ratio, as compared to the other groups. In conclusion, the encapsulation of CM in SLN showed a significant effect in accelerating the wound healing activity.