OBJECTIVE: To investigate the effectiveness of a topically applied emulsion of an analgesic ammonium solution for the temporary treatment of pain associated with arthritis, tendinitis, and bursitis. DESIGN: 100 subjects in a single center, presenting with chronic pain associated with arthritis, tendinitis, or bursitis trialed against placebo in a double-blind cross-over protocol. MAIN OUTCOME MEASURES: Measures of treatment success include reduction in pain, improvement in clinical and/or mechanical evaluations, and evaluation of local and systemic adverse effects. Analysis was conducted at two weeks, after one week’s clearance, and again after two weeks. RESULTS: For chronic neuralgia associated with arthritis, tendinitis, and bursitis, the test material had a positive effect at temporary pain reduction. Several subjects also recorded improvements in mechanical evaluations from baseline. Withdrawals due to systemic or local adverse reactions were minimal. CONCLUSION: A topical emulsion of a strong ammonium solution utilizing quaternary ammonium, enhanced with certain penetration enhancers, is effective for temporary relief of pain associated with arthritis, tendinitis, and bursitis. Altern Med Rev 1998;3(5):361-366.