Claims for Patent: 6,028,222

Summary for Patent: 6,028,222

Title:	Stable liquid paracetamol compositions, and method for preparing same
Abstract:	Novel stable paracetamol compositions for use in therapeutic chemistry and specifically galenic pharmacy are disclosed. The compositions contain a solution of paracetamol in an aqueous solvent combined with a buffer having a pH of 4 to 8, and a free radical capturing agent. A water-insoluble inert gas is carefully bubbled through the aqueous solvent to remove oxygen from the medium. Said compositions may also be combined with a centrally or peripherally acting analgesic agent, and are provided as injectable compositions for relieving pain.
Inventor(s):	Dietlin; Francois (Le Pecq, FR), Fredj; Daniele (Gif-sur-Yvette, FR)
Assignee:	SCR Pharmatop (FR)
Application Number:	09/051,246
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 6,028,222
Patent Claims:	1. A stable, liquid formulation consisting essentially of acetaminophen dispersed in an aqueous medium containing a buffering agent and at least one member of the group consisting of a free radical scavenger and a radical antagonist. 2. The formulation of claim 1 wherein the aqueous medium has been deoxygenated by bubbling a water-insoluble inert gas. 3. The formulation of claim 1 wherein the aqueous medium is buffered at a pH of 4 to 8. 4. The formulation of claim 3 wherein the aqueous medium is buffered at a pH of 5.5 to 6. 5. The formulation of claim 1 containing a free radical antagonist selected from the group consisting of ascorbic acid ascorbic acid derivatives, organic compounds having at least one thiol and a alkyl polyhydroxylated and cycloalkyl polyhydroxylated compounds. 6. The formulation of claim 5 wherein the ascorbic acid derivatives ar selected from the group consisting of D-ascorbic acid, L-ascorbic acid, alkali metal ascorbates, alkaline earth metal ascorbates and water-soluble ascorbic acid esters. 7. The formulation of claim 5 wherein the organic compound having at least one thiol is aliphatic or cycloaliphatic. 8. The formulation of claim 1 containing a free radical scavenger containing at least one thiol is selected from the group consisting of thiolyglycolic acid, thiolacetic acid, dithiothreitol, reduced glutathion, thiourea, .alpha.-thioglycerol, cystein, acetlcystein and mercaptoethane sulfonic acid. 9. The formulation of claim 1 wherein the free radical scavenger is an aliphatic polyhydroxy alkanol of 2 to 10 carbon atoms. 10. The formulation of claim 9 wherein the polyhydroxy alkanol is a cyclic glucitol or a straight chain glucitol of 6 to 10 carbon atoms. 11. The formulation of claim 9 wherein the polyhydroxy alkanol is glycerol or propyleneglycol. 12. The formulation of claim 10 wherein the cyclic glucitol is selected from the group consisting of mannitol, sorbitol, inositol, glucose and levulose. 13. The formulation of claim 1 also containing at least one complexing agent. 14. The formulation of claim 1 wherein the acetaminophen has a concentration of 2 to 350 mg/ml. 15. The formulation of claim 14 wherein the concentration is 60 to 350 mg/ml. 16. The formulation of claim 14 diluted to a concentration of 2 to 50 mg/ml. 17. The formulation of claim 1 also containing an isotonizing agent in an amount to obtain isotonicity. 18. The formulation of claim 1 sterilized by heat treatment. 19. The formulation of claim 1 further containing an effective amount of an analgetic agent. 20. The formulation of claim 19 the analgetic agent is a morphine analgetic selected from the group consisting of natural morphines, semi-synthetic morphines, synthetic morphines, phenylpiperidines, nipecotic acid compounds, phenylcyclohexanol compounds and phenylazepine compounds. 21. The formulation of claim 20 having a concentration of acetaminophen is 0.05 to 5% by weight when morphine is present. 22. The formulation of claim 20 having an acetaminophen concentration of 0.2 to 2.5% by weight when codeine is present. 23. The formulation of claim 1 further containing an anti-inflammatory agent of the phenylacetic acid type. 24. The formulation of claim 23 wherein the anti-inflammatory agent is ketoprofen. 25. The formulation of claim 1 further containing an antiemetic agent. 26. The formulation of claim 1 further containing an antipileptic agent. 27. The formulation of claim 1 further containing a corticosteroid. 28. The formulation of claim 1 further containing a tricyclic antidepressant.