Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Tablets – lozenges – or pills
Reexamination Certificate
1999-03-26
2002-04-02
Page, Thurman K. (Department: 1615)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Tablets, lozenges, or pills
C424S464000, C424S465000, C424S466000, C424S468000, C424S469000, C424S470000, C424S471000, C424S472000
Reexamination Certificate
active
06365185
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to tablets which are time-controlled controlled to release active agent at different rates in different regions of the digestive tract in order to maintain a substantially constant concentration in the blood.
2. Description of the Related Art
The development of novel peroral drug delivery systems for achieving controlled administration of the active agent with minimum dependability on drug and environmental properties, has attracted a great deal of interest. Among the first systems designed and marketed successfully was the elementary osmotic pump. This system consists of a compacted core coated with a microporous, semipermeable membrane having a delivery orifice drilled in the coating by LASER. The core tablet consists of either an osmotically active therapeutic compound or a mixture of an osmotically active agent and the therapeutic compound. The osmotic pump imbibes water, dissolving the drug in the core and the drug solution is delivered through the delivery orifice at steady state and at a rate controlled by the rate of influx of the water across the semipermeable membrane.
The delivery devices described above operate successfully for their intended use and they can deliver many beneficial agents for their intended effects. Now, it has been observed their use can be limited because they lack the necessary elements to deliver beneficial agents at the appropriate amounts for the environments encountered in the gastrointestinal tract.
It will be appreciated by those versed in the dispensing arts that if a delivery system is provided for administering at a controlled rate throughout the entire gastrointestinal tract, the different absorptive rates of the various sections of the tract will result in a change in the blood levels of the delivered compound.
SUMMARY OF THE INVENTION
The goal of the present invention is to design a system or device which contains, instead of an osmotically active agent, a dry swelling material and instead of a semipermeable membrane by spray-or dip-coating, a semipermeable shell by press-coating and an exit means through which the drug solution is expelled at a predetermined rate over a period of 8 or 14 hours for a 12 or 24 hours duration of effect. The exit means may be a delivery orifice which can be made by a stylus in the upper punch of the compression tools. The advantage of the present system is the adaptability to manufacturing on a compression coating machine, in one single step.
Once the delivery system of the present invention reaches the large intestine, where absorption of drug is slower because of mucosal viscosity of the intestinal contents, the shell of the device self-destructs destructs thus releasing the drug at an accelerated rate.
It is accordingly an object of the present invention to provide a delivery device for the oral administration of a pharmaceutically acceptable active agent to a warm-blooded animal, with increasing delivery rate, particularly to the lower portion of the small intestine and/or the colon, more particularly to the colon.
It is another object of this invention to provide a dosage form for delivering substantially all of a therapeutic drug to the colon.
It is yet another object of this invention to provide a dosage form which comprises a core tablet coated with a delay jacket for delaying the delivery of the drug to insure the time required for the dosage form to travel through the small intestine.
These, and other objects apparent to those skilled in the art from the following detailed description, are accomplished by the present invention which pertains to the delivery of a therapeutic drug to a pre-selected region of the gastrointestinal tract, by means of a drug delivery device. This drug delivery device comprises:
REFERENCES:
patent: 4673405 (1987-06-01), Guittard et al.
patent: 5531736 (1996-07-01), Wong et al.
patent: 5580979 (1996-12-01), Bachovchin
patent: 5607697 (1997-03-01), Alkire et al.
patent: 5681583 (1997-10-01), Conte et al.
patent: 5707654 (1998-01-01), Beres et al.
patent: 5780055 (1998-07-01), Habib et al.
patent: 5824339 (1998-10-01), Shimizu et al.
M.A. Agrawal and W.A. Ritschel, Evaluation of a New Peroral Modified Release System in Human Subjects (abstract), aaps American Association of Pharmaceutical Scientists, 1977.
David R. Swanson, Ph.D. et al., Nifedipine Gastrointestinal Therapeutic System, The American Journal of Medicine, vol. 83 (suppl 6B), Dec. 21, 1987.
W.A. Ritschel, A. Sabouni, and MA Agrawal, Novel p.o. drug delivery system: Compression-coated hydrogel piston pump. 1. Shell thickness and pore size., Pharmaceutical and Pharmacological Letters, vol. 6, No. 3, Dec. 1996.
W.A. Ritschel, A. Sabouni, and M.A. Agrawal, Novel p.o. drug delivery system: Compression-coated hyudrogel piston pump. 2. Design and in vitro evalution, Pharmaceutical and Pharmacological Letters, vol. 6, No. 3, Dec. 1996.
W.A. Ritschel et al., Permeability of [3H]Water Across a Porous Polymer Matrix used as Rate-Limiting Shell in Compression-coated Tablets, Journal of Controlled Release, 12 (1990) 97-102.
Bengt Lindstedt et al., Osmotic pumping release from KCI tablets coated with porous and non-porous ethylcellulose, International Journal of Pharmaceutics, 67 (1991) 21-27.
WA Ritschel, Biopharmaceutic and Pharmacokinetic Aspects in the Design of Controlled Release Peroral Drug Delivery Systems, Drug Development and Industrial Pharmacy, 15(6&7), 1073-1103 (1989).
Gaylen M. Zentner et al., Osmotic Flow Through Controlled Porosity Films: An Approach To Delivery Of Water Soluble Compounds, Journal of Controlled Release, 2 (1985) 217-229.
Wolfgang A. Ritschel et al., Evaluation of a Controlled Release Osmotic Pump Type of Dosage Form for Chlorpheniramine Maleate, Eur. J. Pharm. Biopharm. 40(3) 122-127 (1994).
Agrawal Mukul A.
Ritschel Wolfgang A.
Page Thurman K.
Tran S.
University of Cincinnati
Wood Herron & Evans LLP
LandOfFree
Self-destructing, controlled release peroral drug delivery... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Self-destructing, controlled release peroral drug delivery..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Self-destructing, controlled release peroral drug delivery... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2887538