Claims for Patent: 4,657,900

Summary for Patent: 4,657,900

Title:	Pharmaceutical article of manufacture comprising a bisulfite stabilized aqueous solution of 5-aminosalicylic acid and method
Abstract:	An aqueous suspension of pure 5-aminosalicylic acid adapted for rectal administration is rendered storage stable against color formation by storing the suspension in a single dose polyethylene bottle adapted for rectal administration of the suspension, in a substantially oxygen-free atmosphere and in the presence dissolved therein of up to about 0.25% of bisulfite and protecting the suspension from exposure to atmospheric oxygen during storage by sealing the plastic bottle, in a substantially oxygen-free atmosphere, in a plastic pouch having a low oxygen transmission rate.
Inventor(s):	Powell; David R. (Baudette, MN), Patel; Vithal K. (Baudette, MN)
Assignee:	Rowell Laboratories (Baudette, MN)
Application Number:	06/717,062
Patent Claims:	1. A pharmaceutical article of manufacture comprising: (a) a first sealed container, adapted for storing aqueous liquids, substantially free of atmospheric oxygen; (b) contained in the first sealed container, a stable suspension adapted for rectal administration of substantially pure 5-aminosalicylic acid in a saturated, substantially colorless and substantially oxygen-free aqueous solution of 5-aminosalicylic acid of pharmaceutical grade purity having a pH of from about 3 to 5 and rendered resistant to color formation upon storage by the presence dissolved therein at a concentration of up to about 0.25% w/w, of an amount of bisulfite effective to stabilize the solution against color formation and degradation of the 5-aminosalicylic acid by the reaction with any trace amount of oxygen in the solution or the container; and; (c) a second sealed container containing the first container stored therein in substantially oxygen-free atmosphere, and comprising an oxygen barrier effective to prevent transmission into the interior of the second container upon prolonged storage of atmospheric oxygen in an amount sufficient to exhaust the bisulfite dissolved in the solution contained in the first container. 2. An article according to claim 1 wherein the first container is a plastic bottle. 3. An article according to claim 1 wherein the first container is a single unit dosage disposable collapsible enema polyethylene bottle with a dispensing tip adapted for rectal administration of the 5-ASA solution therein. 4. An article according to claim 1 wherein the oxygen barrier of the second container comprises aluminum foil. 5. An article according to claim 1 wherein the second container is a sealed plastic pouch. 6. An article according to claim 1 wherein the first container is a single unit dosage disposable collapsible enema polyethylene bottle with a dispensing tip adapted for rectal administration of the 5-ASA solution therein and the second container is a sealed plastic pouch. 7. An article according to claim 6 wherein the pouch is formed at least in part from aluminum foil. 8. An article according to claim 1 wherein the solution contains about 0.1 to 0.2% w/w bisulfite dissolved therein. 9. A suspension according to claim 1 wherein the bisulfite is present as potassium metabisulfite. 10. A suspension according to claim 1 wherein the solution contains an amount of floculating agent effective to stabilize the suspension against caking of the undissolved 5-aminosalicylic acid. 11. An article according to claim 10 wherein the floculating agent is a water gellable polyacrylic acid. 12. An article according to claim 1 wherein the solution contains an amount of a thickener effective to stabilize the suspension against settling of the undissolved 5-aminosalicylic acid therefrom. 13. An article according to claim 12 wherein the thickener is xanthan gum. 14. An article according to claim 6 wherein the solution contains on a w/w basis about 1.5-10% of 5-aminosalicylic acid, up to about 0.2% by weight of sodium bisulfite, an amount of floculating agent effective to stabilize the suspension against caking of the undissolved 5-aminosalicylic acid and an amount of a thickener effective to stabilize the suspension against settling of undissolved 5-aminosalicylic acid therefrom. 15. An article according to claim 14 wherein the pouch is formed at least in part from aluminum foil. 16. A method of protecting a substantially colorless aqueous solution of substantially pure 5-ASA from decomposition and color formation therein upon prolonged storage, which comprises the steps of: (a) maintaining the solution during storage in the presence dissolved therein of an amount of bisulfite effective only to protect the 5-ASA against decomposition and color formation resulting from reaction of the 5-ASA with a trace amount of atmospheric oxygen present prior to storage but ineffective to protect against atmospheric oxygen transmitted to the solution during storage; (b) storing the solution in a sealed container which contains therein no more than a trace amount of atmospheric oxygen; and (c) protecting the solution from contact with atmospheric oxygen during storage. 17. A method according to claim 16 wherein the sealed container is a plastic bottle or pouch in the form of a single unit dosage disposable collapsible enema bottle with a dispensing tip adapted for rectal administration of the 5-ASA solution therein and the solution contained therein is adapted for rectal administration and contains undissolved substantially pure 5-ASA suspended therein. 18. A method according to claim 17 wherein the plastic bottle is formed of a plastic having a substantial oxygen transmission rate and the 5-ASA solution is protected from contact with atmospheric oxygen during storage by a sealed second container in which the plastic bottle is stored and which is formed of a material having an oxygen transmission rate substantially lower than the plastic bottle. 19. A method according to claim 18 wherein the second sealed container is a pouch formed of a plastic laminate comprising aluminum foil. 20. A method according to claim 17 wherein the sealed container in which the solution is stored is a plastic bottle or pouch formed of a material having an oxygen transmission rate low enough to protect the solution against atmospheric oxygen being transmitted thereto during storage.