Capsaicin is an active principle of the plant Capsicum annum (Solanaceae L.) It is used in the topical preparations in concentration of 0.025 to 0.075% as counter-irritant. Clinical research reaffirmed topical use of capsaicin in the cases of polyneuropathy, rheumatoid arthritis, diabetic and postherpetic neuropathy. Topically applied capsaicin demonstrates counter-irritant effect and produces heat, which leads to pain relief. Pain is the major symptom of neuralgia.

The aim of this study was to establish counter-irritant effect of capsaicin, which was incorporated in emulsion base O/W, gel and alcohol-water solution after preparations administered to the skin of healthy volunteers.

Capsaicin (Aldrich, USA) was incorporated in emulsion vehicle O/W, gel and alcohol-water solution in concentration of 0.025%. Affects of single applications of prepared preparations were researched preparations on peripheral circulation of the skin in the in vivo test. Equal amounts of preparations were applied to the inside forearm skin of 8 healthy volunteers. Temperature of the skin was measured before administration and 0.5, 1, 2, 4, 6 and 8 hours after application of cream, gel and solution with incorporated active principle. For temperature skin measure, Toff-guard INMT instrument was used (Organon Teknika, Belgie).

After preparation administration, increase of skin temperature was noted at the application spot. The cream caused the highest increase of the skin temperature (3 hours after cream application, the skin temperature increased for 1.5°C) but 3 hours after solution application, the skin temperature increased for 0.5°C was registered.