Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Tablets – lozenges – or pills
Reexamination Certificate
2000-06-29
2003-08-19
Page, Thurman K. (Department: 1615)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Tablets, lozenges, or pills
C424S468000, C424S489000, C424S488000
Reexamination Certificate
active
06607748
ABSTRACT:
FIELD OF INVENTION
The present invention relates to a novel form of cross-linked high amylose starch and processes for its manufacture. Such cross-linked high amylose starch is useful as an excipient in a controlled-release pharmaceutical formulation when compressed with a pharmaceutical agent(s) in a tablet.
BACKGROUND OF THE INVENTION
One of the critical factors influencing the rate of absorption of a drug administered as a tablet or other solid dosage form is the rate of dissolution of the dosage form in the body fluids of human or animal.
This factor is the basis for the so-called controlled-release, extended-release, sustained-release or prolonged-action pharmaceutical preparations that are designed to produce slow, uniform release and absorption of the drug over a period of hours, days, week, months, or years. Advantages of controlled-release formulations are a reduction in frequency of administration of the drug as compared with conventional dosage forms (often resulting in improved patient compliance), maintenance of a therapeutic effect over a set period of time, and decreased incidence and/or intensity of undesired side effects of the drug by elimination of the peaks in plasma concentration that often occur after administration of immediate-release dosage forms.
Many systems have been proposed and developed as matrices for the release of drugs. For example, polymeric materials such as polyvinyl chloride, polyethylene amides, ethyl cellulose, silicone and poly (hydroxymethyl methacrylate), have been proposed as vehicles for the slow release of drugs. See U.S. Pat. No. 3,087,860 to Endicott et al; U.S. Pat. No. 2,987,445 to Levesque et al.; Salomon et al., Pharm. Acta Helv., 55, 174-182 (1980); Korsmeyer, Diffusion Controlled Systems: Hydrogels, Chap. 2, pp 15-37 in Polymers for Controlled Drug Delivery, Ed. Tarcha, CRC Press, Boca Raton, Fla. USA (1991); Buri et al, Pharm. Acta Helv. 55, 189-197 (1980).
A substantial need exists for a controlled release composition that can deliver a variety of drugs, both hydrophilic and hydrophobic, in a consistent and reliable manner. Further, this composition should be amenable to all facets of tableting requirements, including, but not limited to, direct compression, appropriate hardness and resistance to friability, and compatibility with the active ingredient(s) contained in the tablet. Also, the composition should be easy to synthesize, biodegradable and non-toxic upon release of the drug.
One of the most widely studied compounds for controlled-release use has been starch, partially because it is biodegradable and is naturally metabolized by the human body [Kost et al., Biomaterials 11, 695-698 (1990)]. Starch has many uses in pharmaceutical products. It can act as a diluent, filler, carrier, binder, disintegrant, coating, thickener, and moisture sink. See U.S. Pat. No. 2,938,901 to Kerr et al., which discloses the use of granular starch cross-linked with sodium trimetaphosphate as a surgical dusting powder; U.S. Pat. No. 3,034,911 to McKee et al., which discloses the use of a cold water swelling and cold water insoluble starch in intact granular form as a disintegrant; U.S. Pat. No. 3,453,368 to Magid, which discloses the use of pregelatinized starches, optionally modified as binders for compressed ascorbic acid tablets; U.S. Pat. No. 3,490,742 to Nichols et al., which discloses a non-granular amylose (at least 50%) obtained from the fractionation of corn starch for use as a binder disintegrant in direct compression and dry granulation tablets; U.S. Pat. No. 3,622,677 to Short et al., which discloses the use of a partially cold water soluble and cold-water swelling starch, derived from a compacted granular starch, as a binder-disintegrant; U.S. Pat. No. 4,072,535 to Short et al., which discloses a pre-compacted starch having birefringent granules, non-birefringent granules, and some aggregates and fragments for use as a binder-disintegrant; U.S. Pat. No. 4,026,986 to Christen et al., which discloses the use of water-soluble starch ethers (e.g., hydroxyalkyl ethers) containing at least 50% amylose for use in forming capsule shells; U.S. Pat. No. 4,308,251 to Dunn et al., which discloses the use of corn, rice, potato and modified starches as an erosion-promotion agent in controlled release formulations prepared by wet granulation; U.S. Pat. No. 4,551,177 to Trabiano et al., which discloses the use of acid- and/or alpha-amylase converted starches as tablet binders; U.S. Pat. No. 4,904,476 to Mehta et al., which discloses the use of sodium starch glycolate as a disintegrant; U.S. Pat. No. 4,818,542 to DeLuca et al., which discloses starch as a biodegradable or bioerodible polymer for porous microspheres possibly coated with a cross-linking agent to inhibit or control drug release; U.S. Pat. No. 4,888,178 to Rotini et al., which discloses the use of starch, preferably maize starch, and sodium starch glycolate as disintegrants in the immediate release of a programmed release Naproxen® formulation containing immediate release and controlled release granulates in the form of tablets, capsules, or suspension in a suitable liquid media; U.S. Pat. No. 5,004,614 to Staniforth, et al., which discloses the use of starches as pharmaceutical fillers in controlled release devices containing an active agent and a release agent and the use of cross-linked or un-cross-linked sodium carboxymethyl starch for the coating.
U.S. Pat. No. 4,369,308 to Trubiano et al. discloses modified starches which are low swelling in cold water and which are suitable for use as disintegrants in compressed tablets. This is achieved by cross-linking and pregelatinizing in the presence of water, a cold-water insoluble, granular starch, drying the cross-linked, pregelatinized starch if necessary, and then pulverizing the dry starch. No controlled release properties are disclosed or claimed for these starches.
Cross-linked starch has been previously evaluated as a sustained release agent. Visavarungroj et al. [Drug Development And Industrial Pharmacy, 16(7), 1091-1108 (1990)] discloses the evaluation of different types of cross-linked starches and pregelatinized cross-linked starches for their use as hydrophilic matrices. It was determined that cross-linked starches demonstrated a poor swelling power and dispersion viscosity in comparison to pre-gelatinized starch and pregelatinized cross-linked starch. The study concluded that cross-linked modified waxy corn starches, either pregelatinized or not, in comparison to purely pregelatinized waxy corn starch are not suitable to use as a hydrophilic matrix in sustained release formulation.
Nakano et al. [Chem. Pharm. Bull. 35(10), 4346-4350, (1987)] disclose the use of physically modified starch (pregelatinized starch) as an excipient in sustained-release tablets. This article does not mention the specific role of amylose present in starch nor does it even mention amylose.
Van Aerde et al. [Int. J. Pharm., 45, 145-152, (1988)] disclose the use of modified starches obtained by drum-drying or extrusion pregelatinization, particle hydrolysis or cross-linking with sodium trimetaphosphate, as an excipient in sustained-release tablets. Once again, the article does not mention the specific role of amylose present in starch nor does it even mention amylose.
Herman et al. [Int. J. Pharm., 56, 51-63 & 65-70, (1989) and
Int. J. Pharm
., 63 201-205, (1990)] disclose the use of thermally modified starches as hydrophilic matrices for controlled oral delivery. This article discloses that thermally modified starches containing a low amount of amylose (25% and lower) give good sustained release properties, contrary to high amylose content starches which present bad controlled release properties.
U.S. Pat. No. 3,490,742 to Nichols et al. discloses a binder-disintegrant comprising non-granular amylose. This material is prepared either by fractionating starch or by dissolving granular high amylose starch in water at an elevated temperature. No controlled release properties are disclosed.
U.S. P
Beck Roland Herwig Friedrich
Chouinard Francois
Désévaux Cyril
Höpcke Reiner
Lenaerts Vincent
Fubara Blessing
Page Thurman K.
Pennie & Edmonds LLP
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