Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Tablets – lozenges – or pills
Reexamination Certificate
1999-02-12
2001-06-12
Page, Thurman K. (Department: 1615)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Tablets, lozenges, or pills
C424S468000
Reexamination Certificate
active
06245357
ABSTRACT:
FIELD OF THE INVENTION
This invention pertains to both a novel and therapeutically useful dosage form. The invention, more particularly, relates to a dosage form that administers a dose of drug in an extended and linear-release profile for an indicated therapy. Specifically, the invention concerns a dosage form comprising a drug formulation enveloped by two walls with the formulation and walls acting in concert to provide the extended, linear-nondeclining-release drug delivery profile. The invention concerns also a method of administering the dosage form to provide a dose of drug for therapy.
BACKGROUND OF THE INVENTION
To improve the effectiveness of drug therapy and to reduce possible systematic side effects, many attempts have been made to deliver drugs in a controlled profile to human patients. The advantage of controlled release dosage forms are well-known in both the pharmaceutical and medical sciences. The therapeutical benefits of controlled-release dosage forms include the pharmacokinetic ability to maintain a preplanned blood level of an administered drug over a comparatively longer period of time. The therapeutical benefits include also a simultaneous increase in patient compliance and a reduction in the number of doses of drug administered to a patient.
The prior art made available controlled release dosage that sought to provide a drug release rate profile that matched the blood physiological and chrono-pharmacological requirements needed for therapy. For example, an osmotic dosage form for delivering various drugs to a patient environment of use is presented in U.S. Pat. No. 3,845,770 issued to patentees Theeuwes and Higuchi, and in U.S. Pat. No. 3,916,899 issued to the same patentees. The dosage forms disclosed in these patents are manufactured comprising a wall that surrounds a compartment comprising a drug with an exit in the wall for delivering the drug to a patient. In U.S. Pat. Nos. 4,008,719; 4,014,334; 4,058,122; 4,116,241; and 4,160,452 patentees Theeuwes and Ayer made available dosage forms comprising an inside and an outside wall made of poly(cellulose acylate) for delivering a dosage of drug to a patient in need thereof.
The history of the prior art dosage forms indicates a serious need exists for a novel and useful dosage form that provides an unexpected advancement in the science of dosage forms. For example, the prior art dosage forms lack the present ability to mask an unpleasant taste, they did not maintain the stability of a drug formulation, and the dosage forms did not protect a drug from oxidation. Then too, the drug formulation in the dosage form permitted the drug release profile to decline over time, thereby administering a nontherapeutic dose of drug. The wall of the dosage forms exposed to the gastrointestinal tract were lipophilic, they absorbed endogenous fats and consequently evidenced a decrease in structural integrity as seen in flaws or cracks in the wall. Moreover, the dosage forms wall and its drug formulation did not act in concert for providing a controlled linear drug delivery profile over an extended time. Likewise, prior art dosage forms were formulated with water-leachable components within the membrane to control delivery rate of drug which water-leachable components diffused from the membrane against the direction of osmotic water flux making reproducibility and control of delivery rate patterns difficult, as seen in U.S. Pat. No. 5,160,744.
It is clear from the above presentation that a long-felt need exists for a dosage form comprising a walled structure and a drug formulation that function together for administering orally a drug at a controlled and sustained-release drug delivery profile with time. The need exists for a dosage form for administering a drug in a linear profile for treating infectious diseases, respiratory diseases, the cardiovascular system, blood and spleen, the digestive system, metabolic disorders, the endocrine system, the urogenital tract, sexually transmitted diseases, the nervous system, the locomotor system, psychiatric disorders and for providing symptomatic care. A dosage form is needed for replacing immediate-release dose-dumping forms administered three or four times daily. There are serious reasons for seeking a dosage form that replaces immediate-release forms, including a means for reducing peak-blood levels followed by a sharp drop in blood levels, a means for lessening side effects, a means for manufacturing the structural integrity of the dosage form, and a means for reducing the number of solvents used to manufacture the dosage form.
OBJECTS OF THE INVENTION
Accordingly, in view of the above presentation, it is an immediate object of this invention to provide both a novel and a useful dosage form that overcomes the disadvantages associated with the prior art.
Another object of the present invention is to satisfy a long-felt need by making available a dosage form that administers a drug in a linear profile over time.
Another object of the present invention is to provide a dosage form comprising a formulation comprising a drug and a first and second wall which formulation and walls operate together to deliver a drug in a linear rate over an extended time.
Another object of the invention is to provide a dosage form comprising an inside wall and an outside wall which outside wall protect the inside wall from the environment of the gastrointestinal tract.
Another object of the invention is to provide a bilayer wall that maintains its physical and chemical integrity during the administration of a drug.
Another object of the present invention is to provide a dosage form manufactured as an osmotic drug delivery device by standard manufacturing procedures into sizes, shapes and structures that represent an advancement in the drug delivery art.
Another object of the invention is to make available a dosage form comprising an outside bioprotective wall that shields the dosage form from injury and/or destruction in a gastrointestinal environment.
Another object of the invention is to provide a dosage form comprising ethylcellulose and a hydroxyalkylcellulose wall formed from a single solvent system.
Another object of the invention is to provide a dosage form comprising an interior wall comprising an ethylcellulose and a hydroxypropylalkylcellulose shielded by an exterior wall comprising a poly(cellulose acylate) and other wall-forming ingredients.
Another object of this invention is to provide a dosage form comprising an inside wall that comprises a hydrophobic polymer insoluble in the digestive system and hydrophilic polymer soluble in the digestive system which latter polymer dissolves from the wall thereby increasing the porosity and increasing the fluid flux of the wall.
Another object of the invention is to provide a transport mechanism whereby water-soluble flux enhancers within the interior wall during the operation of the dosage form are transported by diffusion from the wall in the same direction as the osmotic water-flow passing through the bilayer wall.
Another object of the invention is to provide a dosage form comprising an interior seamless wall that surrounds a formulation containing a drug, and an exterior seamless wall that surrounds the interior wall, which dual walls avoid a break-up in the gastrointestinal tract while keeping the structural integrity of the dosage form.
Another object of the invention is to provide a method for treating a patient with a medication administered from a controlled-release dosage form.
Another object of this invention is to provide a method for administering an effective dose of a medicament at a sustained release rate to provide a therapeutically effective blood level of the medicament for 30 minutes to 24 hours, which sustained release rate provided by the invention is free from changes induced by the environment of the gastrointestinal tract.
Another object of the invention is to provide a method for administering an opioid medicament from a sustained release dosage form into the gastrointestinal tract for producing an opioid medicament level
Bhatti Gurdish Kaur
Edgren David E.
Li Shu
Skluzacek Robert R.
Wong Patrick S.-L.
ALZA Corporation
Dhuey John A.
Fubara Blessing
Page Thurman K.
Stone Steven F.
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