Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Implant or insert
Patent
1996-02-09
1998-09-08
Knode, Marian C.
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Implant or insert
425435, 425489, 425490, 425491, 425492, 425493, 425494, 127 65, 127 71, A61F 1300, A61K 914, A61K 916, C08B 3000
Patent
active
058042091
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/EP95/02044 filed May 30, 1995.
The present invention relates to bioadhesive starches, to a process for their preparation and to pharmaceutical compositions containing them. It also relates to the use of such bioadhesive starches as carriers for the administration of a drug.
In the administration of a drug it may be important to maintain the pharmaceutical dosage form for a sufficiently long time in a suitable place for the absorption. As reported by Duchene D. et al. in "Drug Development and Industrial Pharmacy" 14 (2&3), 283-318 (1988), bioadhesion could lead to the solution of bioavailability problems resulting from a too short stay of the pharmaceutical dosage form at the absorption or activity level of the active ingredient. In the same article bioadhesion is defined "as the ability of a material (synthetic or biological) to adhere to a biological tissue for an extended period of time. This definition includes a large number of adhesion phenomena: the adhesion of various shellfish on rocks, the adhesion of cells on one another, and the adhesion of microorganisms on various mucosa substrates. . . . For bioadhesion to occur, a succession of phenomena is required, whose role depends on the bioadhesive nature. Bioadhesion stages can be summarized as follows. First an intimate contact must exist between the bioadhesive and the receptor tissue. This contact results either from a good wetting of the bioadhesion surface, or from the swelling of the bioadhesive. When contact is established, the penetration of the bioadhesive into the crevice of the tissue surface then takes place, or interpenetration of bioadhesive chains with those of the mucus. Low chemical bonds can then settle."
J. R. Robinson in U.S. Pat. Nos. 4,615,697 and 4,795,436, both named "Bioadhesive Compositions and Methods of Treatment Therewith" describes the use of "water-swellable but water-insoluble, fibrous, cross-linked carboxy-functional polymer, said polymer containing (a) a plurality of repeating units of which at least about 80 percent contain at least one carboxyl functionality, and (b) about 0.05 to about 1.5 percent cross-linking agent substantially free from polyalkenyl polyether, said percentages being based upon the weights of unpolymerized repeating unit and cross-linking agent, respectively."
In these Robinson's patents the use of synthetic, cross-linked polymers is done to obtain good bioadhesive properties. In the present invention the materials used are only derived from natural products by very simple physical modifications. Considering the safety, the use of a natural product like starch vs. a synthetic polymer has to be considered an improvement. The carboxyl functionality present in the Robinson's bioadhesives may also give stability problems due to the marked chemical reactivity of carboxyl functionality. This functionality is also very sensible to the pH of the environment, producing different bioadhesive patterns depending on pH. Modified starches have been described in the scientific and patent literature for their bioadhesive properties in particular to give buccal; controlled-release, bioadhesive dosage forms.
Bioadhesive starches obtained by spray-drying or drum-drying are reported by Bottenberg P., et al., "Development and Testing of Bioadhesive, Fluoride-containing Slow-release Tablets for Oral Use", J. Pharm. Pharmacol., 1991, 43: 457-464. In this article formulations were prepared starting from, among other polymers, "drum-dried waxy maize (DDWM, mol. wt 4.000.000) and spray-dried waxy maize (SDWM, mol. wt 4.000.000) (Cerestar, Vilvoorde, Belgium)". The article concludes "that bioadhesive polymers such as thermally modified corn starch with 5% polyacrylic acid or polyethylene glycol (mol. wt 300.000) can be used as a slow-release device for fluoride. The system we describe is a positive step in the development of dose-efficient fluoride administration in the oral cavity."
The same first author had previously filed a patent application: Bottenberg P., Remon J. P., De Muynck C., "
REFERENCES:
patent: 3025217 (1962-03-01), Bernstein etal.
patent: 5204108 (1993-04-01), Illum
Database WPI, Derwent Publications Ltd., JP A 61 148 114, Jul. 5, 1986.
Junginger et al, Deutsche Apotheker Zeitung, "Bioadhasive Arzneistoffabgabesystem", vol. 130, No. 15, pp. 791-801.
De Ponti Roberto
Martini Alessandro
Muggetti Lorena
Knode Marian C.
Pharmacia S.p.A.
Salimi Ali R.
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