Rheumatologists are keenly interested in finding medical approaches to arthritis pain which are effective, and do not cause problems for other organs including the kidney, liver and gastrointestinal system. Traditional nonpharmacological approaches to osteoarthritis management include physical therapy, exercise and weight control programs, often effective as additions to medications delivered either directly to the joint by injection or taken by mouth.
Few studies have systematically compared topical nonsteroidals (compounded and applied locally), to the same agents taken by mouth. Although the skin provides a certain barrier to systemic absorption, topical NSAIDs have been traditionally regarded as offering similar risk to patients as oral medication. New data from Germany has challenged this assumption. A group from IDEA AG in Munich recently examined tiny nanoparticles (called transfersomes) which are mixed with a nonsteroidal in aqueous suspension, and applied directly to the skin.
Transfersomes are carriers which bind an active substance in an aqueous gel, transporting medication through the outer layers of the skin. Once applied, the water in the suspension evaporates, leaving active NSAID to diffuse through the skin. In the German study, a transfersome/ketoprofen suspension (labeled IDEA-033) was compared to transfersome/placebo applied twice a day for 12 weeks in patients with knee osteoarthritis. Standardized pain scales were used to analyze clinical responses, and scores were significantly improved in patients taking the study drug.
Toxicity data in IDEA-033 recipients was identical to placebo with respect to gastrointestinal side effects; of note, there was no bleeding in either group. A comparator drug taken by mouth (Celebrex, in standard doses) had twice as many gastrointestinal side effects, including bloating, nausea and stomach upset. Skin irritation was predictably more frequent in the study drug recipients compared to placebo, while the calculated systemic absorption of IDEA-033 was 1-5 percent of medication taken by mouth.
In summary, topical nonsteroidal therapy, when delivered by a novel carrier molecule, demonstrated benefit, with enhanced safety and equivalent efficacy compared to conventional oral medication. This small study offers hope for another potential therapeutic option in patients with osteoarthritis who may not be candidates for NSAID therapy.
Published On: February 14, 2008