 23. Use of any prescription or non-prescription medication, including vitamins or herbal medications, within 7 days, or 5 half-lives if known, whichever is longer, prior to dosing in any of the 3 periods and within 24 hours after dosing in any period. The use of acetaminophen, naproxen, and ibuprofen is permitted except for within 24 hours prior to dosing; 