Title:  Bioadhesive progressive hydration tablets

United States Patent:  6,624,200

Issued:  September 23, 2003

Inventors:  Bologna; William J. (Paris, FR); Levine; Howard L. (Oceanside, NY); DeZiegler; Dominque (Paris, FR)

Assignee:  Columbia Laboratories, Inc. (Livingston, NJ)

Appl. No.:  877218

Filed:  June 11, 2001

Abstract

A bioadhesive composition wherein the active ingredient may be protected from water or the surrounding environment, thereby protecting it from metabolism or from other degradation caused by moisture, enzymes, or pH effects, and making it bioavailable only at a controlled rate. The active ingredient may be protected from moisture during the manufacturing process and more importantly may be protected from moisture and the immediate septic environment until after the patient has applied the composition, and then only at a slow and controlled rate. It is by this process of progressive hydration that the active ingredient remains protected for many hours after administration. It is also by the process of progressive hydration that controlled and sustained release is achieved because only that part of the active ingredient that is the hydrated (aqueous) fraction of the composition is available for absorption (bioavailable).

SUMMARY OF THE INVENTION

The present invention meets the aforementioned needs in the art. Accordingly, it is an object of the invention to provide a bioadhesive tablet that adheres immediately or almost immediately to the target tissue area of a body cavity and generally stays attached substantially throughout treatment. In accordance with this aspect of the invention, there is provided a bioadhesive tablet that can stay attached and deliver active ingredients in the buccal cavity for as much as eighteen hours or more. In accordance with a related aspect of the invention, there is provided a bioadhesive tablet that can stay attached and deliver active ingredients vaginally for as much as 72 hours or more.

It is another object of the invention to provide a bioadhesive tablet that progressively hydrates, whereby the inner core of the tablet remains protected from moisture and the surrounding environment. In accordance with this aspect of the invention there is provided a bioadhesive tablet suitable for sustained release use in mucosal and other body cavities even with active ingredients comprising proteins or glycoproteins or other treating agents that are particularly susceptible to metabolism, or to enzymatic, pH, or moisture-induced degradation.

It is a related object of the invention to provide a bioadhesive tablet having both controlled and sustained release properties due to a tablet formulation wherein the active ingredient is only progressively made bioavailable over an extended time period by the progressive hydration of the tablet's dry reservoir of active ingredient.

It is another object of the invention to provide a bioadhesive tablet according to the invention that also gelifies and/or swells to help protect a patient using the tablet buccally from asphyxiation, particularly a sleeping patient undergoing treatment.

It is yet another object of the invention to provide methods of making bioadhesive tablets in accordance with the aforementioned objects of the invention. In accordance with one aspect of the invention, there is provided a method of making bioadhesive tablets wherein an active ingredient resistant to premature metabolism and/or degradation is added in the first and/or second step (manufacture of granulate). In accordance with a related aspect of the invention there is provided a method of making bioadhesive tablets wherein an active ingredient prone to premature metabolism and/or degradation is added in the second step (manufacture of the tableting mixture) after the granulate is dried and sieved. Of course, other concerns or factors may affect the choice of which step or steps are appropriate for adding a particular active ingredient.

It is yet another object of the invention to provide methods of using bioadhesive tablets as described herein. In accordance with one aspect of the invention, there is provided a method of using a bioadhesive tablet to administer to a male patient a sustained release of testosterone. In accordance with a related aspect of the invention, there is provided a method of using a bioadhesive tablet to administer to a female patient a sustained release of a hormone, such as testosterone.

The inventors of the present invention have discovered, quite unexpectedly, that these and other objects for the invention may be achieved by making and using tablets comprising an active ingredient, water soluble polymers (e.g., carbomer 974P or 934P, or CARBOPOL.TM. 974P), and insoluble polycarbophil (e.g., NOVEON.RTM., available from B. F. Goodrich Specialty Polymers of Cleveland, Ohio), and preferably hydroxypropylmethyl cellulose (HPMC), lactose, corn starch and other standard tablets ingredients, such as magnesium stearate, talc, and silica.

Bioadhesive, progressive hydration tablets according to the invention may be used with any suitable active ingredient and may be used to deliver a therapeutic amount of the active ingredient to a patient at controlled rates for sustained periods of time. Tablets according to the invention may also be constructed in any suitable shape and any suitable size consistent with the intended therapeutic use of the tablet.

Tablets according to the invention may comprise any suitable amount of active ingredient. Suitable amounts of active ingredient according to the invention may be from minuscule amounts to about 50%, or more. As will be appreciated by one of ordinary skill in the art, "minuscule amounts" is intended to cover those amounts of active ingredient that are disproportionately small relative to the tablet, for example, when only a few micrograms of active ingredient are to be delivered via a tablet weighing over a hundred milligrams. Accordingly, one of ordinary skill in the art will appreciate that any amount of active ingredient, in any ratio, is within the scope of the present invention.

The balance of the tablet according to the invention may comprise water soluble polymer(s) and water insoluble cross-linked polycarboxylic polymer(s). Also, according to the invention, exemplary tablets preferably have between about 1% and about 75% by weight water soluble polymer (preferably carbomer 974P) and between about 0.5% and about 10% by weight water insoluble, water-swellable cross-linked polycarboxylic polymer (preferably Polycarbophil). In accordance with the invention, such exemplary tablets also preferably include between about 5% and about 50% cellulose. Also in accordance with the invention, presently preferred tablets may have between about 0.5% and about 25% by weight starch. These preferred tablets may also have between about 1% and about 50%, or as much as 95%, by weight lactose.

Furthermore, according to the invention, preferred tablets may comprise from about 0.01% up to about 2% silica; and/or up to about 5% to 8% by weight talc; and/or up to about 2.5% by weight magnesium stearate.

Accordingly, one of ordinary skill in the art will appreciate that the components of the tablets can be varied to suit a particular purpose. For example, the inventors of the present invention have discovered that one way of increasing (decreasing) the time it takes a progressive hydration tablet to hydrate is by increasing (decreasing) the amount of lactose and/or starch and decreasing (increasing) the amount of water-soluble polymer. Alternatively, the density of the tablet may be altered to affect the hydration period.

Active ingredients suitable for use in the present invention include any active ingredient or ingredients requiring sustained or controlled release, any active ingredient or ingredients requiring extended protection from premature degradation by moisture, pH effects, or enzymes, or any active ingredient requiring administration to a patient with protection from first-pass hepatic metabolism. Exemplary active ingredients suitable for use with the present invention include, but are by no means limited to: (1) glycoproteins, such as follicle-stimulating hormone (FSH), luteinizing hormone (LH), human chorionic gonadotropin (HCG), thryoid-stimulating hormone (TSH), and the like; (2) proteins, such as GnRH (agonist and antagonist), oxytocin analogs, somatostatin analogs, tissue plaminogen activator (TPA), growth hormone releasing hormone (GHRH), corticotropin-releasing hormone analogs (CRH analogs), and the like; (3) sex hormones, such as estradiol, testosterone, progesterone, and the like; (4) anti-hormones, such as tamoxifen, mifepristone, and the like; (5) nitrates, such as nitroglycerin, isosorbide, erythrityl tetranitrate, pentaerythritol tetranitrate, and the like; (6) beta-agonists, such as terbutaline, albuterol, pirbuterol, bitolterol, ritodrine, and the like; (7) beta-antagonists, such as propranolol, metoprolol, nadolol, atenolol, timolol, esmolol, pindolol, acebutolol, labetalol, and the like; (8) opioids, such as morphine, hydromorphone, oxymorphone, codeine, hydrocodone, oxycodone, leverophanol, levallorphan, buprenorphine, fentanyl, nalbuphine, butorphanol, pentazocine, and the like; (9) opioids-antagonists, such as naloxone, nalmefene, and the like; (10) antidepressants, such as amitriptyline, amoxapine, desipramine, doxepin, imipramine, maprotilen, nortriptyline, protripyline, trimipramine, fluoxetine, trazodone, and the like; (11) HMG CoA reductase inhibitors, such as lovastatin, mevastatin, simvastatin, pravastatin, atorvastatin, and the like; (12) antihistamines, such as loratadine, chlorpheniramine maleate, brompheniramine maleate, diphenhydramine, dimenhydrinate, carbinoxamine, promethazine, tripelannamine, and the like; (13) ACE inhibitors, such as captopril, enalapril, lisinopril, and the like; and, (14) prostaglandins, such as misoprostol and the like. Accordingly, one of ordinary skill in the art will appreciate that tablets according to the invention may be used with a wide variety of active ingredients to treat a wide variety of conditions.

The present invention also provides a pharmaceutical composition comprising an effective amount of active ingredient that is metabolized by 5.alpha.-reductase, a water insoluble, water-swellable cross-linked polycarboxylic polymer, and a water soluble polymer, wherein said composition is formulated to deliver said active ingredient to the bloodstream of a mammal through a mucosal surface of the mammal.

The present invention further provides a method of delivering to a mammal an active ingredient that is metabolized by 5.alpha.-reductase, comprising administering said active ingredient via a progressive hydration bioadhesive composition through a mucosal surface of the mammal.

In addition, the present invention provides a composition for delivering to the bloodstream of a mammal an active ingredient that is metabolized by 5.alpha.-reductase, comprising a water insoluble cross-linked polycarboxylic polymer, and a water soluble polymer, wherein said composition is formulated to deliver said active ingredient through a mucosal surface of the mammal.

In addition, the present invention provides a bioadhesive progressive hydration pharmaceutical composition comprising: an effective amount of testosterone, a water insoluble, water-swellable cross-linked polycarboxylic polymer, and a water soluble polymer, wherein said composition is formulated to deliver said testosterone to the bloodstream of a mammal through a mucosal surface of the mammal.

In addition, the present invention provides a bioadhesive progressive hydration pharmaceutical composition comprising an effective amount of terbutaline, a water insoluble, water-swellable cross-linked polycarboxylic polymer, and a water soluble polymer, wherein said composition is formulated to deliver said terbutaline to the bloodstream of a mammal through a mucosal surface of the mammal.

In addition, the present invention provides a method of delivering to a mammal an effective amount of testosterone via a progressive hydration bioadhesive pharmaceutical composition through a mucosal surface of the mammal, comprising said testosterone, a water insoluble, water-swellable cross-linked polycarboxylic polymer, and a water soluble polymer.

In addition, the present invention provides a method of delivering to a mammal an effective amount of terbutaline via a progressive hydration bioadhesive pharmaceutical composition through a mucosal surface of the mammal, comprising said terbutaline, a water insoluble, water-swellable cross-linked polycarboxylic polymer, and a water soluble polymer.

Preferably, the compositions of the present invention are formulated to deliver said active ingredient via the mammal's vaginal, buccal, nasal or rectal cavity.

The aforementioned and other aspects of the invention will become more clear by reference to the Figures and descriptions of preferred embodiments.

Before the tablet is administered all of the active is in the dry state and thus, not subject to the deleterious action of moisture, pH effects, enzymes or other chemicals. It is also not available for absorption (bioavailable).  Over time the residual portion of the active remains in the dry state which both protects it from water and the immediate environment as well as allowing it to serve as a reservoir for the sustained and controlled release of the active. Such a delivery system is well suited for the delivery of proteins, glycoproteins, and other drugs which must be protected from metabolism or during prolonged administration from enzymatic, pH, or moisture-induced degradation.

In a preferred embodiment, when used buccally, progressive hydration of the bioadhesive tablet protects the patient, should the tablet become dislodged, by gelifying and becoming heavier and thus less likely to float in the airway, risking aspiration. This makes this embodiment particularly well suited for agents that should reach their peak levels in the middle of the night, e.g., hormones like testosterone or steroids to treat asthma. According to the invention, the hydration of the tablet can preferably take hours (e.g. 12 to 24 hours) when formulated for buccal tablets or even days when formulated for vaginal use. As will be appreciated by one of ordinary skill in the art, prior art bioadhesive tablets do not protect the active ingredient from moisture, pH, or from enzymes produced by bacteria in the septic oral and vaginal orifices.

Furthermore, as will be appreciated by one of ordinary skill in the art following the teaching of the present application, the tablet can be sized, shaped and dosed to meet the needs of the particular treatment being undertaken. For example, the buccal bioadhesive tablet depicted in FIG. 1 was constructed to be only 9 mm in diameter for the comfort of the patient, but made capable of delivering 7 mg of testosterone per day, full physiologic level. By contrast, prior art transdermal patches were only capable of delivering 5 mg per day, in other words a sub-physiologic level.

A presently preferred method of manufacturing bioadhesive tablets is diagramed in FIG. 2. The presently preferred method involves three steps as described below:

1. First step: manufacture of the granulate.

Hydroxypropylmethyl cellulose 15000(=HPMC 15000) is mixed with corn starch and lactose and in case of an active ingredient not sensitive to moisture the active is added. The mixture is wet with an aqueous solution of hydroxypropylmethyl cellulose 5 (=HPMC 5) and knead/granulated.

The granulate is dried in an oven under warm air (50^oC.) until moisture content is less than 2.5%.

The dried granulate is broken with a stainless steel sieve oscillating granulator mesh size 1000 .mu.m.

2. Second step: the tableting mixture.

Talc, silicon dioxide magnesium stearate, and in a case of an active ingredient sensitive to moisture, the active ingredient is added. All is sieved through a sieving machine having aperture size 500 .mu.m and then transferred into a free-fall mixer.

Addition of the granulate of step 1, followed by polycarbophil, carbomer and lactose. The whole is mixed until homogenous.

3. Third step: tableting.

The tableting mixture is compressed into tablets by means of a rotative tableting machine equipped with punches 9 mm flat on the upper side and curved (r=9 mm) on the lower side both with beveled edge. The tablets are dedusted and packed.

An active ingredient that is not sensitive to moisture is preferably added during the manufacture of the granulate. However, alternatively, the active ingredient can be added during the second step after the granulate is dried and sieved. Also, as will be appreciated by one of ordinary skill in the art, this second method is particularly preferred when the active ingredient is sensitive to moisture.

In a presently preferred manufacturing process, the active ingredient is preferably protected from moisture. A wet granulation is made of lactose, corn starch and HPMC. Testosterone, polycarbophil, carbomer 974P, talc and magnesium stearate are added dry for the final compression.

Furthermore, as will be appreciated by one of ordinary skill in the art following the teaching of the present application, the materials of construction can be varied to optimize the desired characteristics of the tablet. For example, the present inventors have discovered that by progressively increasing the amount of lactose and corn starch and progressively decreasing the amount of carbomer 974P, the amount of time it takes a tablet to hydrate is progressively increased. Accordingly, as will be appreciated by one of ordinary skill in the art, tablets suited for specific treatments (i.e., specific active, specific dose, specific delivery time) can be manufactured.

Claim 1 of 13 Claims

We claim:

1. A bioadhesive, controlled and sustained release, progressive hydration pharmaceutical composition comprising:

an effective amount of terbutaline,

a water insoluble, water-swellable cross-linked polycarboxylic polymer, and

a water soluble polymer,

wherein said composition is formulated to deliver said terbutaline to the bloodstream of a mammal through a mucosal surface of the mammal.

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