Comparison of poultice-type and tape-type patches containing ketoprofen on human skin irritation.

Although the patch test for visual skin observation is widely used clinically, it does not allow the mechanisms of side effects to be assessed. In this study, we examined poultice-type KP801 and tape-type KP-T patches containing ketoprofen. The parameters to measure side effects on skin were peeling intensity, amount of stripped stratum corneum, skin moisture and redness of skin color under various mechanical conditions. Since the amount of stripped stratum corneum with the tape-type KP-T patch was higher than with the poultice-type KP801 patch, the bio-adhesive strength of the latter was concluded to be lower. A clear relationship exists between the amount of stripped stratum corneum and skin moisture after tape-type patch removal, but this was not found with the poultice-type patch because of its hydration effects. Peeling intensity, one parameter to predict pain at the time of patch removal, was higher with the KP-T. As for mechanical conditions, when the patch is removed, it is important to remove it as slowly as possible and horizontally, and to avoid any rise in skin temperature. Finally, when a patch is applied to a region with little skin moisture, the amount of stripped stratum corneum may increase accordingly.