Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Matrices
Reexamination Certificate
1998-10-09
2003-08-19
Webman, Edward J. (Department: 1617)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Matrices
C424S485000, C424S468000, C424S472000, C424S499000, C514S961000
Reexamination Certificate
active
06607751
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a controlled release device which provides sustained or pulsatile delivery of pharmaceutically active substances for a predetermined period of time. This invention further relates to such device in which sustained or pulsatile delivery is obtained by the unique blend and intimate mixture of pharmaceutically active substances with a microbial polysaccharide and uncrosslinked linear polymer and optionally a crosslinked polymer and/or lipophillic polymer and/or saturated polyglycolyzed glyceride. The invention also relates to a process for the manufacture of such devices and pharmaceutical compositions containing the same.
BACKGROUND OF THE INVENTION
The prior art teaches many systems for the delivery of pharmaceutically beneficial agents. One such system operates by means of an osmotic pumping mechanism. However, it suffers from being very complex and is complicated to manufacture. A second type of pharmaceutical delivery system utilizes hydrogels either from a group consisting of uncrosslinked linear polymers or from a group consisting of crosslinked polymers. In devices using uncrosslinked polymers, viscosity is the rate controlling factor for drug release kinetics. In these systems a gelatinous layer is formed on the surface upon hydration. The thickness and durability of this gelatinous layer depends upon the concentration, as well as the molecular weight and viscosity of the polymer in the device. At higher concentrations the linear polymer chains entangle to a greater degree leading to virtual crosslinking and a stronger gel layer. Drug release is by the dissolution of polymer and erosion of the gel layer and hence the rate of erosion is what controls the release rate. Although viscosity is an important consideration in controlled drug release from hydrogel matrices, it is viscosity under low shear conditions that control diffusion through the matrix.
Several U.S. Patents are directed to the various pharmaceutical delivery systems as mentioned above, see for example U.S. Pat. Nos. 3,845,770, 3,916,899, 4,016,880, 4,160,452 and 4,200,098. While these systems do provide for the delivery of a selected pharmaceutical agent, none of these provide a controlled or pulsatile delivery of the pharmaceutical agent in which drug release is modulated by combining a microbial polysaccharide and uncrosslinked polymer. Furthermore, none of the prior art teaches a device comprising a microbial polysaccharide and uncrosslinked polymer and optionally a crosslinked polymer and/or lipophillic polymer and/or saturated polyglycolyzed glyceride.
There was therefore a need to develop a novel controlled release pharmaceutical delivery device which could be made in a cost efficient manner and provide for either sustained or pulsatile delivery of the selected pharmaceutical incorporated therein.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a novel controlled pharmaceutical release device capable of delivering in a controlled, continuous or pulsatile manner therapeutically effective amounts of pharmaceutically active agent for a predetermined period of time in mammals, especially human beings.
According to an object of the present invention is a controlled pharmaceutical release device for use with a selected pharmaceutical to provide continuous or pulsatile therapeutically effective amounts of the pharmaceutical, the device comprising;
about 1 to 60% by weight microbial polysaccharide; and
about 1 to 60% by weight uncrosslinked linear polymer.
The device may optionally comprise about 1 to 50% by weight crosslinked polymer, about 1 to 50% by weight lipophillic polymer and/or 1 to 50% by weight saturated polyglycolyzed glyceride.
According to another object of the present invention is a pharmaceutical composition which provides controlled release of the pharmaceutical contained therein, said composition comprising;
about 1 to 60% by weight microbial polysaccharide;
about 1 to 60% by weight uncrosslinked linear polymer; and
about 1 to 80% by weight pharmaceutical active.
The composition may optionally comprise about 1 to 50% by weight crosslinked polymer, about 1 to 50% by weight lipophillic polymer and/or 1 to 50% by weight saturated polyglycolyzed glyceride. According to yet a further object of the present invention is a method for making a controlled release formulation of pharmaceutically active agents, said method comprising:
blending about 1 to 80% by weight pharmaceutical active with about 1 to 60% by weight microbial polysaccharide and about 1 to 60% by weight uncrosslinked linear polymer to form a homogeneous blend;
granulating said homogeneous blend and kneading to form wet granules;
drying the wet granules to a loss on drying of about <5%;
size reducing the dried granules to provide a granule size of about <1400 microns;
blending the dried granules with about 0.5 to 10% lubricant; and
compressing the lubricated granules into tablets.
Preferably, the pharmaceutically active agent is intimately mixed with a microbial polysaccharide and uncrosslinked linear polymer and further wet granulated, dried, sieved, lubricated and pressed into tablets.
Optionally, to the mixture of pharmaceutical active, microbial polysaccharide and uncrosslinked linear polymer may be added about 1 to 50% by weight crosslinked polymer, about 1 to 50% by weight lipophillic polymer and/or 1 to 50% by weight saturated polyglycolyzed glyceride.
In a further aspect of this invention there is provided a method for delivering soluble or poorly soluble pharmaceutically active agents by deliberate and expert manipulation of the composition and ratios of a microbial polysaccharide, preferably xanthan gum, and uncrosslinked linear polymer, preferably hydroxypropylmethyl cellulose polymers, present in the device. The composition and ratios of the optional crosslinked polymer, preferably Carbopol 971P, and/or lipophillic polymer, preferably glyceryl behenate, and/or saturated polyglycolyzed glyceride, preferably gelucire 44/14, may also be manipulated to vary the type of release provided.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The novel controlled delivery device of the present invention provides the controlled release of a selected pharmaceutically active agent in a sustained or a pulsatile manner. In one embodiment, the device is formulated as a composition comprising pharmaceutically active agents in a sustained release matrix tablet. In another embodiment, a method is provided for making the controlled release pharmaceutical delivery device.
The present invention is simple in fabrication, permitting efficient and reproducible mass production by conventional techniques.
The device comprises a mixture of about 1 to 60% by weight uncrosslinked linear polymers and about 1 to 60% by weight microbial polysaccharides to which about 1 to 80% by weight selected pharmaceutical active is added. Suitable pharmaceuticals for use in the device include but are not restricted to diltiazem, glipizide, buspirone, tramadol, gabapentin, verapamil, etodolac, naproxen, diclofenac, COX2 inhibitors, budesonide, venlafaxine, metoprolol, carbidopa, levodopa, carbamazepine, ibuprofen, morphine, pseudoephedrine, paracetamol, cisapride, pilocarpine, methylphenidine, nifedipine, nicardipine, felodipine, captopril, terfenadine, pentoxifylline, fenofibrate, aciclovir, zidovudine, moclobemide, potasium chloride, lamotrigine, citalopram, cladribine, loratadine, pancrelipase, lithium carbonate, orphenadrine, ketoprofen, procainamide, ferrous sulfate risperidone, clonazepam, nefazodone, lovastatin, simvastatin, pravachol, ketorolac, hydromorphone, ticlopidine, seligiline, alprazolam, divalproex and phenytoin.
Uncrosslinked linear polymers suitable for use in the present invention are cellulose ethers preferably hydroxypropylmethyl cellulose (HPMC). Suitable microbial polysaccharides for use in the invention include xanthan gum.
The device may optionally comprise about 1 to 50% by weight crosslinked polymer, preferably Carbopol 971P, about 1 to 50% by weight lip
Odidi Amina
Odidi Isa
Foley & Hoag LLP
Intellipharamaceutics Corp.
Webman Edward J.
LandOfFree
Controlled release delivery device for pharmaceutical agents... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Controlled release delivery device for pharmaceutical agents..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Controlled release delivery device for pharmaceutical agents... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3098174