The study was to compare single-dose oral bioavailability of acetaminophen 650 mg extended release geltabs (containing acetaminophen 650 mg) of OHM Laboratories Inc. (subsidiary of Ranbaxy Pharmaceuticals Inc., USA) with Tylenol 8 hour extended release gel tabs (containing acetaminophen 650 mg) of McNeil Consumer & Speciality Pharmaceuticals, U.S.A in healthy, adult, male human subjects under fasting condition.