Topical agents like nonivamide and nicoboxil induce hyperaemisation and increase cutaneous blood flow and temperature. This study aimed to determine the effects of a nonivamide-nicoboxil cream on haemodynamics in the skin and calf muscle, via optical spectroscopy, discriminating between the changes for skin and muscle. Optical spectroscopy was applied in the visible (VIS) and near-infrared (NIR) wavelength range. The study determined the effect of the cream on changes in oxygenated (ΔoxyHb) and deoxygenated (ΔdeoxyHb) haemoglobin in skin and muscle, as well as on tissue oxygen saturation (SO2) in the skin of 14 healthy subjects. The left and right calves of the subjects were either treated with nonivamide-nicoboxil cream or were sham-administered. NIR spectroscopy allows noninvasive in-vivo examination of the oxygenation of human skeletal muscle. Topical administration of the nonivamide-nicoboxil cream significantly increased the concentration of oxygenated haemoglobin and tissue oxygen saturation in the skin, as well as the concentration of oxygenated haemoglobin in the muscle of the treated legs after 15 min, but with stronger and faster effects in the skin. The topical application of the nonivamide-nicoboxil cream increased blood flow in (smaller vessels of) the skin and muscle tissues.

Topical agents inducing hyperaemisation like nonivamide or nicoboxil increase cutaneous blood flow and temperature and induce erythema. It is not proven up to now whether there is also a hyperaemisation effect in skeletal muscle. This study has the objective to determine the effects of a nonivamide / nicoboxil cream on haemodynamics in skin and calf muscle via optical spectroscopy in the visible and near-infrared with a separation of changes for skin and muscle. Left and right calves of 14 healthy subjects were treated with a nonivamide / nicoboxil cream or mock administration, and cutaneous and muscle haemoglobin were measured using a combined NIRS / VIS sensor. The topical application of the cream increased the concentration of oxygenated haemoglobin and tissue oxygen saturation significantly in skin as well as in muscle of the treated legs already after 15 minutes, with stronger and faster effects in skin. In contrast, the change in deoxygenated haemoglobin was found to be small. The kinetic of all changes varied widely between the subjects. The found haemoglobin changes might explain the beneficial effect of hyperaemisation creams for the treatment of minor injuries.