Evaluation of percutaneous absorption and skin irritation of ketoprofen through rat skin: in vitro and in vivo study

The influences of different mechanisms of penetration enhancers (such as me nthol, atone, ethanol and nonivarnide) regarding the percutaneous absorptio n and skin irritation of ketoprofen formulations through rat skin were inve stigated by in vitro and in vivo study. The skin irritation degree at the e nd of the experiment (10 h) was determined by pathologic biopsy and colorim etry methods. In vitro, the menthol showed the most potent enhancing effect . Furthermore, the enhancement effect of a combination of menthol and noniv amide was higher than that of their individual use alone. In vivo the formu lation containing 0.05% nonivantide, 5% menthol and 20% ethanol showed a hi gher penetration rate and an acceptable degree of skin irritation compared to a commercial product (Formax plus((R)) gel containing 3% ketoprofen), in dicating that it could be used in the clinical situation. (C) 2001 Elsevier Science B.V. All rights reserved.