Evaluation iontophoretic delivery of a cationic ketoprofen prodrug for treating nociceptive symptoms in monosodium iodoacetate induced osteoarthritic rat model

Topical nonsteroidal anti-inflammatory drugs have been used in treatment of osteoarthritis but their efficacy is marginal. One major reason is because of limited drug direct penetration to affected joint and muscle tissues from the topical application. The main purpose of this study was to evaluate a new topical treatment through enhancing the direct drug penetration to local muscle and joint tissues for improving topical treatment of osteoarthritis. A cationic prodrug, ketoprofen choline chloride (KCC) was synthesized for iontophoretic topical delivery. Anodal iontophoretic delivery of KCC and cathodal iontophoretic delivery of ketoprofen to the knee of live hairless rats were evaluated and the drug concentrations in the joint and muscle tissues over the time were determined. In addition, a knee osteoarthritis rat model was induced with intra-articular injection of monosodium iodoacetate solution. Anodal iontophoretic delivery of KCC, cathodal iontophoretic delivery of ketoprofen, or anodal iontophoretic delivery of sodium chloride were applied to the affected knee joint of each rat group, respectively. Knee joint pain was evaluated through a hind paw weight bearing study and knee joint inflammation was evaluated through measuring of the knee diameter. Iontophoretic delivery of KCC showed much higher drug concentration in the knee joint and muscle tissues, compared to iontophoretic delivery of ketoprofen. Treatment of rat knee joint with anodal iontophoresis of KCC also showed significant pain relief and knee inflammation reduction comparing to the control group, while treatment results from cathodal iontophoresis of ketoprofen were mostly not significantly different from the control group.