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Preparation method of microdispersed tablet formulation of spray-dried sodium diclofenac enteric-coated microcapsules

Assignee: Standard Chemical and Pharmaceutical Corp Ltd
•
Filing: 1990-12-31
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Granted: 1993-04-13
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Expires: 2010-12-31
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Abstract

Abstract A preparation method of sodium diclofenac enteric-coated microcapsules by spray drying technique comprising the steps of (a) dissolving sodium diclofenac in an appropriate amount of distilled water; (b) adding an effective amount of excipients to the above solution to form a suspension; (c) adding methacrylic acid-ethyl acrylate copolymers (Eudragit L 30D) and polyethyleneglycol 6000 (PEG 6000) as the enteric-coating material to form a slurry; (d) atomizing the slurry to form spray-dried powder; (e) mixing the spray-dried powder with a mixture of microcrystalline cellulose (neocel) and pregelatinized starch (flo-starch); and (f) compressing the powder mixture into a microdispersed enteric tablet. The spray drying technique could be easily performed to prepare the enteric-coated microcapsules with aqueous latex polymer dispersion such as Eudragit L 30D as an enteric-coating polymer.

Inventors

  • 👤 Li J. Chen
  • 👤 Chun N. Chen
  • 👤 Shan Y. Lin

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 12:36
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/14; A61K9/16; A61K9/1605; A61K9/1629; A61K9/1641; A61K31/00; A61K31/185; A61K31/19; A61K31/195; A61K9/1635; A61K9/20; A61K9/2072; A61K9/2077; A61P; A61P29/00

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 96 words
A preparation method of microdispersed tablet formulation with sodium diclofenac enteric-coated microcapsules by spray drying technique comprising the steps of (a) dissolving sodium diclofenac in an appropriate amount of distilled water; (b) adding an effective amount of excipients to the above solution to form a suspension; (c) adding methacrylic acid-ethyl acrylate copolymers and polyethyleneglycol 6000 as the enteric-coating material to form a slurry; (d) atomizing the slurry to form spray-dried powder; (e) mixing the spray-dried powder with a mixture of microcrystalline cellulose and pregelatinized starch; and (f) compressing the powder mixture into a microdispersed enteric tablet.
Claim 2
Dependent Claim 96 words
A preparation method of microdispersed tablet formulation with sodium diclofenac enteric-coated microcapsules by spray drying technique comprising the steps of (a) dissolving sodium diclofenac in an appropriate amount of distilled water; (b) adding an effective amount of excipients to the above solution to form a suspension; (c) adding methacrylic acid-ethyl acrylate copolymers and polyethyleneglycol 6000 as the enteric-coating material to form a slurry; (d) atomizing the slurry to form spray-dried powder; (e) mixing the spray-dried powder with a mixture of microcrystalline cellulose and pregelatinized starch; and (f) compressing the powder mixture into a microdispersed enteric tablet.
Claim 3
Dependent Claim 42 words
The preparation as set forth in claim 1, wherein atomizing is operated at inlet temperature of about 160° C. an outlet temperature of 80° C., and the speed of the drying air being 0.40 m/min and the atomizing air being 1.0 kgf/cm.
Claim 4
Dependent Claim 19 words
The preparation as set forth in claim 1, wherein the mixture of microcrystalline cellulose to pregelatinized starch is 1:1.
Claim 5
Dependent Claim 18 words
The preparation as set forth in claim 1, wherein the methacrylic acid-ethyl acrylate copolymers is an aqua emulsion.

References Cited (Backward Citations)

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US3922338A Cited
US4540602A Cited
US4867987A Cited
US4710384A Cited
US4867985A Cited
US4894239A Cited
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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-04-12 1996-10-12 1997-04-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-04-12 2000-10-12 2001-04-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-04-12 2004-10-12 2005-04-13 $7700.00 Window Closed / Lapsed

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