US5334378A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pharmaceutical formulation in the form of aqueous suspension
Assignee: Rohto Pharmaceutical Co Ltd
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Filing: 1993-03-26
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Granted: 1994-08-02
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Expires: 2013-03-26
Abstract
Abstract A pharmaceutical formulation in the form of aqueous suspension which comprises an ion exchange resin carrying an active ingredient and a suspending agent, characterized in that the formulation further contains a basic or neutral amino acid or a salt thereof as a dispersion stabilizer.
Inventors
- 👤 Youko Mitani
- 👤 Kenji Muta
- 👤 Mitsuo Umemoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:41
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/0087; A61K9/0095; A61K47/00; A61K47/06; A61K47/16; A61K47/18; A61K47/183; A61K47/20; A61K47/50; A61K47/51; A61K47/56; A61K47/58; A61K47/585; A61K9/10
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
128 words
A pharmaceutical formulation in the form of an aqueous suspension capable of maintaining a uniform dispersion upon storage which comprises (a) 0.01-3.00 w/v % of an ion exchange resin carrying an active ingredient capable of being converted into an ionic active ingredient, (b) 0.10-3.00 w/v % of a suspending agent selected from the group consisting of natural gums, nonionic cellulose derivatives and alginates and mixtures thereof, (c) 0.05-2.00 w/v % of a dispersion stabilizer comprising an amino acid selected from the group consisting of glycine, alanine, cystine, valine, lysine, arginine, histidine and salts thereof and (d) 92.00-99.84 w/v % of water, wherein said maintained uniform dispersion is the effect of the amino acid dispersion stabilizer on the ion exchange resin carrying an active ingredient and the suspending agent.
Claim 2
Dependent Claim
128 words
A pharmaceutical formulation in the form of an aqueous suspension capable of maintaining a uniform dispersion upon storage which comprises (a) 0.01-3.00 w/v % of an ion exchange resin carrying an active ingredient capable of being converted into an ionic active ingredient, (b) 0.10-3.00 w/v % of a suspending agent selected from the group consisting of natural gums, nonionic cellulose derivatives and alginates and mixtures thereof, (c) 0.05-2.00 w/v % of a dispersion stabilizer comprising an amino acid selected from the group consisting of glycine, alanine, cystine, valine, lysine, arginine, histidine and salts thereof and (d) 92.00-99.84 w/v % of water, wherein said maintained uniform dispersion is the effect of the amino acid dispersion stabilizer on the ion exchange resin carrying an active ingredient and the suspending agent.
Claim 3
Dependent Claim
15 words
A pharmaceutical formulation of claim 1, wherein the suspending agent is one or more natural-gums.
Claim 4
Dependent Claim
23 words
A pharmaceutical formulation of claim 1, wherein the suspending agent is selected from non-ionic cellulose derivatives consisting of methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose.
Claim 5
Dependent Claim
28 words
A pharmaceutical formulation of claim 1, wherein the concentration of the suspending agent is 0.5 to 1.5 w/v % with respect to the total volume of the formulation.
Claim 6
Dependent Claim
31 words
A pharmaceutical formulation of claim 1, wherein the concentration of the amino acid or its salt is 1.0 to 2 w/v % with respect to the total volume of the formulation.
Claim 7
Dependent Claim
29 words
A pharmaceutical formulation of claim 1, wherein the average particle size of the ion exchange resin carrying the active ingredient is 1 to 500 μm in a dried state.
Claim 8
Dependent Claim
18 words
A pharmaceutical formulation of claim 1, which is weakly acidic or neutral and shows pH 3 to 7.
Claim 9
Dependent Claim
16 words
The pharmaceutical formulation of claim 6 wherein the average particle size is 25 to 250 μm.
Claim 10
Dependent Claim
25 words
The pharmaceutical formulation of claim 1 wherein said active ingredient is selected from the group consisting of codeine, dihydrocodeine, dexstromethorphon, chlorpheniramine, phenylpropanolamine, methylephedrine and hydrocodone.
Claim 11
Dependent Claim
19 words
The pharmaceutical formulation of claim 1 wherein the suspending agent is a combination of tragacanth gum and xanthane gum.
References Cited (Backward Citations)
US2697059A
Cited
FR806M
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-08-01 | 1998-01-31 | 1998-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-01 | 2002-01-31 | 2002-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-01 | 2006-01-31 | 2006-08-02 | $7700.00 | Window Closed / Lapsed |