Monitoring the Clinical Response to an Innovative Transdermal Delivery System for Ibuprofen

Abstract

We present a phase 1 study that utilizes a crossover design that provides a rapid and relatively inexpensive methodology for evaluating a new transdermal product. The treatment for osteoarthritis (OA) aims to reduce pain and improve function. An innovative magnetophoresis technology has been developed that facilitates transdermal delivery of ibuprofen. The study used measures that were taken over a relatively short time period to monitor the pharmacodynamic response to ibuprofen. Each participant received magnetophoresis-enhanced transdermal ibuprofen or placebo in randomised order, with a five-day washout period. The participants were 24 volunteers with medically diagnosed, painful knee OA. The primary outcome measures were VAS rating of pain on movement and Western Ontario and McMaster Universities (WOMAC) pain and function scores. VAS for pain on movement (p < 0.001), WOMAC pain score (p = 0.004), and WOMAC function score (p = 0.004) were all significantly improved. There was a significant reduction in movement-related pain (p < 0.05) during the first patch application and for the remainder of the study period. The number needed to treat for a 50% reduction in movement related pain was 2.2. The study showed a rapid and significant analgesic effect in response to transdermal ibuprofen. A short trial of this nature can be used for informing the parameters that are required for a major randomised controlled trial.