An improved modified release preparation

摘要

Disclosed is a modified release preparation having one or more coated core elements, each core element including an active ingredient selected from the group consisting of the acid salts of doxycycline, tetracycline, oxytetracycline, minocycline, chlortetracycline or demeclocycline and having a modified release coating, wherein a stabilising coat is provided between each core element and its modified release coating so that, upon in vitro dissolution testing, the amount of active ingredient released at any time on a post-storage dissolution profile is within 40 percentage points of the amount of active ingredient released at any time on a pre-storage dissolution profile.