EP1555022A1 — Sustained release compound of acetamidophenol and tramadol

USPTO Abstract

A sustained release formulation as a unit dose contains 100 mg - 1000 mg of Acetaminophen and 15 mg - 150 mg of tramadol hydrochloride, which comprises of 1) an immediate release portion comprising of 25% - 75% of the total effective amount of drug in the dosage form and 2) a sustained release portion comprising of a) 25% - 75% of the total effective amount of drugs in the dosage form; b) 6% - 50% of gelling polymers of the total formulation, and c) optionally an enteric coating at a level of 5% - 40% of the total formulation. The set forth formulation dissolves 25% - 60% of the total drug in the first hour, 50% - 90% of the total drug in the first four hours and not less than 80% of the total drug in the first 12 hours using USP dissolution method II at 50 rpm.