Thermosensitivity of a Topical Palmitated Formulation of Capsaicin

This is a study of the effects of capsaicin, the ingredient that makes hot peppers hot. Capsaicin is currently used in topical ointments to provide temporary relief of minor aches and joint pain associated with arthritis, simple backache, strains, and sprains.This is a pilot research study that compares the potential of two different capsaicin creams to cause irritation or burning sensation when a small amount (about the size of a quarter) is applied to each forearm of a participant. The amount of capsaicin used in the creams is the same as those found in over-the-counter capsaicin products. The test creams are experimental.

Inclusion Criteria:35 to 75 years of ageHas two armsHas intact, unscarred skin over forearmsAbsence of any eczema, hyperkeratosis, scleroderma or other dermatological conditions afflicting the area of test article application that may interfere with absorption as determined by the PI.Must agree to not wash forearms during the study period unless a highly uncomfortable burning sensitivity occurs.Must be willing to use treatments blinded.Must be willing and able to comply with protocol requirements for the duration of study participation, including answering VAS queries in good faith and as diligently as possible.Exclusion Criteria:Younger than 35 and older than 75 years of ageNo previous use of capsaicin products for 48 hours prior to time 0 (application) of test articles.Any dermatological conditions that in the judgement of the study site investigator has the potential to disrupt skin integrity or alter sensory function on the forearms.Any skin infection, skin irritation (e.g. poison oak), history of eczema, trauma or burn (including sunburn) on the forearms within 30 days preceding application of test article.Any recent medical history of painful conditions, surgery, or injury involving or affecting the forearms that may impede skin sensitivity.Use of any topically applied products at any location, including prescription or over-the-counter (OTC) analgesic creams/lotions/patches, non-steroidal anti-inflammatory drugs, counter-irritants, local anesthetics, steroids 24 hours prior to the application visit.History or current substance abuse including alcoholism/alcohol abuse, as judged by the study site investigator.History of hypersensitivity to capsaicin (i.e. chili peppers or OTC capsaicin products).At least 30 days since prior topical medications to the skin of the forearms except for emollients or sunscreens.No concurrent therapy that may interfere with clinical evaluations.No concurrent enrollment in another clinical trial.