Evaluation of the topical spray containing Centella asiatica extract and its efficacy on excision wounds in rats

Centella asiatica was extracted by methanol. The assay content of triterpenes in the extract was 0.12 % asiatic acid, 0.54 % madecassic acid, 0.25 % asiaticoside and 1.02 % madecassoside. The extract was complexed with hydroxypropyl-β-cyclodextrin (HP-β-CD) and formulated with Eudragit E100, glycerol, PEG 400, copovidone, ethanol and purified water. A clear yellowish solution (F1-F8) was obtained. The formulations had a pH of 5.5-6.0 with viscosity in the range of 20-60 mPa s, surface tension 20.3-24.6 mN m-1 and contact angle less than 20°. The amount of PEG 400 and copovidone affected the film and spreadability. The content of triterpenes in the spray formulation was close to 100 % compared to triterpenes in the extract. The skin irritation study indicated that the formulation was non-irritating in a rat model. An in vivo excision wound healing model showed that wound excision was completely healed after 14 days.