Appeal No. 95-4962
Application No. 07/972,660
Claim 1 is representative of the subject matter on appeal
and reads as follows:
1. A targeted drug release formulation for delivery of
drugs to the intestinal tract of the ileum and colon of a
mammal consisting essentially of a plurality of multidose
minitablet units each said unit having a particle size of less
than about
5 mm and consisting essentially of a minitablet core
containing a drug selected from the group consisting of
penicillin G, calcitonin, heparin, ferritin, sucralfate,
mebeverine hydrochlorate, acarbase dimethycone, simethicone
and immunoglobulin surrounded by two membranes consisting
essentially of a pH dependent polymer which is soluble at a pH
greater than about 5.5 and the second of said membranes
consisting essentially of one or more polymers such that said
second membrane is substantially insoluble in but permeable to
gastric fluids, and wherein
a) said formulation is characterized with a
dissolution rate in a simulated gastric
environment such that over a period of 8 hours
substantially all of the drug is released, and
the release is further characterized by the
release of no more than about 10% drug after 3
hours and no more than about 75% drug after 6
hours;
b) said pH dependent polymer is selected from the
group consisting of anionic copolymers based on
methacrylic acid and methacrylic acid methyl
ester, cellulose acetate phthalate,
hydroxpropylmethylcellulose phthalate, polyvinyl
acetate phthalate, shellac,
hydroxpropylmethylcellulose acetate succinate,
carboxymethylcellulose, cellulose acetate
trimellitate, copolymers of maleic acid and
derivatives of phthalic acid; and
c) said substantially insoluble membrane is
selected from the group consisting of copolymers
2
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Last modified: November 3, 2007