Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Tablets – lozenges – or pills
Patent
1990-04-26
1991-09-24
Page, Thurman K.
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Tablets, lozenges, or pills
424451, 424489, 424499, 424501, 424 78, 424 81, A61K 310, A61K 306, A61K 307
Patent
active
050512617
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
This invention relates to a method for preparing a dosage form, such as a tablet, a bead or the like, with a controlled and delayed release of the active ingredient and the controlled release dosage form made by the process.
It is known to produce solid pharmaceutical or other functionally active preparations which ensure a sustained release of an active ingredient over a long period of time and thus ensure a constant concentration of active ingredient in the body. These delayed release forms make it possible to reduce the number of doses of the drug to be administered daily and thus simplify the treatment plan considerably. Usually delayed release tablets and capsules are provided with a coating which regulates the release of active ingredient.
One disadvantage of relying on coatings for the delayed release property is that any inadvertent puncture of the coating or division of the tablet critically affects the coating integrity or the total surface area of the tablet, that is, some of the barrier coating effectiveness is lost. As a result, the characteristics of the release of active ingredient are significantly altered, so that in many cases, the delayed release tablets no longer have the property of delayed and continuous release of an active ingredient.
In addition, tablets with score lines are known which enable the tablets to be divided into partial doses in order to meet special therapeutic requirements. Divisible tablets of this kind must, in particular, satisfy the requirement of being easy and safe to divide and of ensuring precise dosage, even when broken into fragments.
Microencapsulated formulations do not wholly overcome the problem of controlled release because the film-forming agent frequently forms a continuous phase after a period of time making it impossible to maintain reproducible release rates. U.S. Pat. No. 4,716,041 to Kjornaes et al. teaches a microencapsulated formulation of a first, inner film-forming coating, a second, outer film coating. The coated formulations are subsequently heated to permit the inner film-forming coating to form a continuous phase with uniform diffusion characteristics with time. Such a multiple coating process adds to the expense of a formulation and does not overcome the problem of coating integrity for tablets, caplets and other dosage forms.
Orally administerable pharmaceutical preparations are known in which the active substance is embedded in a polymer or matrix. The matrix slowly dissolves or erodes to release the pharmaceutically active ingredient. The feed formulations of pharmaceutical preparations of this kind are normally produced by dissolving the active ingredient together with a polymer in a solvent, then evaporating the solvent and granulating the solid mixture. Frequently the removal of the solvent and the granulation are carried out in a single operation by spray drying.
Pharmaceutical preparations of this type are intended for the purpose of distributing the active ingredient in a finely dispersed form through the polymer and increasing the surface area of the substance which is to be dissolved, so as to accelerate and not delay the dissolving process.
U.S. Pat. No. 4,547,359 teaches that a divisible polyacrylate-based tablet may be formed of a compressed composition comprising a finely divided polyacrylate material having the active ingredient incorporated therein in molecular dispersion, and conventional tablet excipients. However, the patent teaches it is particularly important to use a specific acrylate polymerized by emulsion polymerization and having a particle size of about 140 nm. Polyacrylates prepared by other methods, such as by solution or block polymerization, are unsuitable for purposes of the invention. In order to ensure a delayed release of the active ingredient, the active ingredient embedded in the polyacrylate material should have diffusion coefficients of 10.sup.-5 to 10.sup.-7 cm.sup.2 per hour. However, it is undesirable to restrict the pharmaceutically active compounds to such a narrow
REFERENCES:
patent: Re27107 (1971-03-01), Levesque
patent: 4059686 (1977-11-01), Tanaka et al.
patent: 4166800 (1979-09-01), Fong
patent: 4181786 (1980-01-01), Mune et al.
patent: 4226848 (1980-10-01), Nagai et al.
patent: 4250163 (1981-02-01), Nagai et al.
patent: 4308251 (1981-12-01), Dunn et al.
patent: 4353887 (1982-10-01), Hess et al.
patent: 4357312 (1982-11-01), Hsieh et al.
patent: 4384975 (1983-05-01), Fong
patent: 4443497 (1984-04-01), Samejima et al.
patent: 4479911 (1984-10-01), Fong
patent: 4499066 (1985-02-01), Moro et al.
patent: 4547359 (1985-10-01), Zierenberg et al.
patent: 4647599 (1987-03-01), Bezzegh et al.
patent: 4652441 (1987-03-01), Okada et al.
patent: 4659558 (1987-04-01), Urquhart et al.
patent: 4661104 (1987-04-01), von Bittera et al.
patent: 4666702 (1987-05-01), Junginger
patent: 4692337 (1987-09-01), Ukigaya et al.
patent: 4716041 (1987-12-01), Kjornaes et al.
patent: 4801460 (1989-01-01), Goertz et al.
patent: 4880585 (1989-11-01), Klimesch et al.
patent: 4908208 (1990-03-01), Lee et al.
Gennaro, A. R., "Remington's Pharmaceutical Sciences", 17th Ed., Mack Publishing Co., Easton, PA. (1985) pp. 277-279; 1603-1615 and 1650-1654.
Watson, P. D., "Lactic Acid Polymers", Industrial and Engineering Chemistry, 40:8, Aug. 1948, pp. 1393-1397.
Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd. Ed., vol. 17, John Wiley & Sons, N.Y., 1982, pp. 298-307.
FMC Corp.'s "Avicel PH" Bulletin pH (1986).
FMC Corp.'s "Avicel RC/CL" Bulletin RC-16 (1986).
Patent Abstracts of Japan, vol. 4, No. 182 C35.
Chang Kuei-Tu
McGinity James W.
Baker P. C.
Elden R. E.
FMC Corporation
Page Thurman K.
Webman Edward J.
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