Antibiotic composition with inhibitor

This application is a continuation of U.S. application Ser. No. 09/791,536, filed Feb. 23, 2001, now U.S. Pat. No. 6,565,882 which claims the priority of United States Provisional Application No. 60/184,582, filed on Feb. 24, 2000.

This invention relates to antibiotics that contain beta-lactam rings that are subject to attack by beta-lactamases in combination with beta-lactamase inhibitors.

Antibiotics with beta-lactam rings, for example, pencillins and cephalosporins, are susceptible to attack from the beta-lactamases (sometimes called penicillinases) that will chemically inactivate the antibiotic. Clavulanic acid, and its derivatives, as well as sulbactam are generally used to bind irreversibly to the beta-lactamase to prevent its activity against such an antibiotic. Typically, there is provided an antibiotic composition that includes the inhibitor with such combinations generally being delivered as an immediate release dosage form.

The present invention relates to an improved antibiotic composition that is comprised of at least four different dosage forms, two of which include at least one antibiotic with a beta-lactam ring (or any portions of such a ring) and two of which include at least one beta-lactamase inhibitor, with the four different dosage forms having release profiles such that there is a first dosage form that releases said at least one antibiotic, a second dosage form that releases at least one beta-lactamase inhibitor, a third dosage form that releases said at least one antibiotic, and a fourth dosage form that releases said at least one inhibitor, with the release profile of the first and second dosage forms being such that the maximum serum concentration of the inhibitor is reached at a time no sooner and preferably after the time at which the maximum serum concentration of the antibiotic released from the first dosage form is achieved, with the third dosage form having a release profile such that the second antibiotic achieves a maximum serum concentration at a time no sooner than and preferably after the time at which the inhibitor released from the second dosage form reaches a maximum serum concentration, and with the fourth dosage form having a release profile such that the maximum serum concentration of the inhibitor released from the fourth dosage form is achieved at a time no sooner and preferably after a time that the maximum serum concentration is reached for the at least one antibiotic released from the third dosage form.

In one preferred embodiment, the initiation of release from the second, third and fourth dosage form occurs at least one hour after initiation of release from the first, second and third form, respectively.

In a preferred embodiment of the present invention, a maximum serum concentration for the antibiotic released from the first dosage form is achieved in no more than about three hours; the maximum serum concentration for the inhibitor released from the second dosage form is reached in a time of from about three to six hours; the maximum serum concentration of the antibiotic released from the third dosage form is reached in from about six to nine hours, and the maximum serum concentration released from the fourth dosage form is achieved in no more than twelve hours, with such times being measured from the time of administration of the antibiotic composition that is comprised of the at least four different dosage forms.

In a preferred embodiment of the present invention, the at least four dosage forms are provided with release profiles such that the inhibitor is released from the second dosage form after the maximum serum concentration is achieved for antibiotic released from the first dosage form; antibiotic is released from the third dosage form after the maximum serum concentration is reached for the inhibitor released from the second dosage form, and inhibitor is released from the fourth dosage form after the maximum serum concentration is reached for the antibiotic released from the third dosage form.

It is to be understood that when it is disclosed herein that a dosage form initiates release after another dosage form, such terminology means that the dosage form is designed and is intended to produce such later initiated release. It is known in the art, however, notwithstanding such design and intent, some “leakage” of antibiotic or inhibitor may occur. Such “leakage” is not “release” as used herein.

Although, in a preferred embodiment there are four dosage forms, it is possible to have more than four dosage forms, provided that there is successive alternate release of antibiotic and inhibitor, and each inhibitor release achieves a serum concentration maximum no sooner than and preferably after the serum concentration maximum of the immediately preceding antibiotic released, and the next antibiotic released reaches a serum concentration maximum no sooner than and preferably after the serum concentration maximum is achieved for the immediately preceding inhibitor dosage form.

In an embodiment of the present invention each of the dosage forms that contains an inhibitor includes such inhibitor in an amount that is effective to inhibit chemical inactivation of the antibiotic by beta-lactamase. In general, the dosage forms that contain the inhibitor contain such an inhibitor in an amount from about 20 percent to about 80 percent.

Similarly, the dosage forms that contain the antibiotic generally include the antibiotic in an amount from about 30 percent to about 80 percent. Each of the dosage forms that deliver antibiotics include from 30% to 70% of the dosage of the antibiotic to be delivered by the composition.

In accordance with a preferred embodiment, the first dosage form that releases antibiotic is an immediate release dosage form. The second, third, and fourth dosage forms are delayed release dosage forms, which may be pH independent or pH dependent (enteric) dosage forms. The second, third and fourth dosage forms are formulated in a matter to provide the release profiles as hereinabove described.

At least four different dosage forms can be formulated into the overall antibiotic composition of the present invention, by procedures generally known in the art. For example, each of the dosage forms may be in the form of a pellet or a particle, with pellet particles being formed into the overall composition, in the form, for example, of the pellet particles in a capsule, or the pellet particles embedded in a tablet or suspended in a liquid suspension.

The antibiotic composition of the prevent invention may be administered, for example, by any of the following routes of administration: sublingual, transmucosal, transdermal, parenteral, and preferably are administered orally. The composition includes a therapeutically effective amount of the antibiotic, which amount will vary with the antibiotic to be used, the disease or infection to be treated, and the number of times that the composition is to be delivered in a day.

The antibiotic product of the present invention, as hereinabove described, may be formulated for administration by a variety of routes of administration. For example, the antibiotic product may be formulated in a way that is suitable for topical administration; administration in the eye or the ear; rectal or vaginal administration; as nose drops; by inhalation; as an injectable; or for oral administration. In a preferred embodiment, the antibiotic product is formulated in a manner such that it is suitable for oral administration.

For example, in formulating the antibiotic product for topical administration, such as by application to the skin, the antibiotic may be formulated for topical administration by including such dosage forms in an oil-in-water emulsion, or a water-in-oil emulsion. In such a formulation, the immediate release dosage forms are in the continuous phase, and the delayed release dosage form is in a discontinuous phase. For example, there may be provided an oil-in-water-in-oil-in-water emulsion, with oil being a continuous phase that contains the immediate release component, water dispersed in the oil containing a first delayed release dosage form, and oil dispersed in the water containing a second delayed release dosage form, and water dispersed in the oil containing a third delayed release dosage form.

It is also within the scope of the invention to provide an antibiotic product in the form of a patch, which includes different antibiotic and inhibitor dosage forms having different release profiles, as hereinabove described.

Furthermore, the antibiotic product with different dosage forms with different release profiles may be formulated for rectal or vaginal administration, as known in the art. This may take the form of a cream or emulsion, or other dissolvable dosage forms similar to those used for topical administration.

As a further embodiment, the antibiotic product may be formulated for use in inhalation therapy by coating the particles and micronizing the particles for inhalation.

In a preferred embodiment, the antibiotic product is formulated in a manner suitable for oral administration. Thus, for example, for oral administration, each of the dosage forms may be used as a pellet or a particle, with a pellet or particle then being formed into a unitary pharmaceutical product, for example, in a capsule, or embedded in a tablet, or suspended in a liquid for oral administration.

Alternatively, in formulating an oral delivery system, each of the dosage forms of the product may be formulated as a tablet, with each of the tablets being put into a capsule to produce a unitary antibiotic product. Thus, for example, antibiotic products may include a first dosage form in the form of a tablet that is an immediate release tablet, and may also include three additional tablets, each of which provides for a delayed release of the antibiotic and inhibitor, as hereinabove described.

As hereinabove described, the antibiotics that are employed in the present invention are ones that include a beta-lactam ring or a portion thereof such as for example, penicillin derivatives, such as penicillin V, penicillin G, penicillin, ampicillin, amoxicillin, carbenicillin, ticarcillin, piperacillin, nafcillin, cloxacillin, dicloxacillin, monobactams such as aztreonam, carbapenems such as imipenem, cephalosporins such as cefoxitan, cephalexin, ceferiaxone, cefuroxime, cefpodoxime, and others.

The beta-lactamase inhibitors maybe any one of a wide variety that are effective to inhibit the action of beta-lactamases on a beta-lactam ring, such as clavulanic acid and its derivatives, sulbactam.

In one embodiment, the product contains sufficient antibiotic for a twenty-four hour period whereby the product is administered once a day.

The Immediate Release Component

The immediate release portion of this system can be a mixture of ingredients that breaks down quickly after administration to release the antibiotic. This can take the form of either a discrete pellet or granule that is mixed in with, or compressed with, the other three components.

The materials to be added to the antibiotics for the immediate release component can be, but are not limited to, microcrystalline cellulose, corn starch, pregelatinized starch, potato starch, rice starch, sodium carboxymethyl starch, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, ethylcellulose, chitosan, hydroxychitosan, hydroxymethylatedchitosan, cross-linked chitosan, cross-linked hydroxymethyl chitosan, maltodextrin, mannitol, sorbitol, dextrose, maltose, fructose, glucose, levulose, sucrose, polyvinylpyrrolidone (PVP), acrylic acid derivatives (Carbopol, Eudragit, etc.), polyethylene glycols, such a low molecular weight PEGs (PEG2000–10000) and high molecular weight PEGs (Polyox) with molecular weights above 20,000 daltons.

It may be useful to have these materials present in the range of 1.0 to 60% (W/W).

In addition, it may be useful to have other ingredients in this system to aid in the dissolution of the drug, or the breakdown of the component after ingestion or administration. These ingredients can be surfactants, such as sodium lauryl sulfate, sodium monoglycerate, sorbitan monooleate, polyoxyethylene sorbitan monooleate, glyceryl monostearate, glyceryl monooleate, glyceryl monobutyrate, one of the non-ionic surfactants such as the Pluronic line of surfactants, or any other material with surface active properties, or any combination of the above.

These materials may be present in the rate of 0.05–15% (W/W).

The Delayed Release Component

The components in this composition are the same immediate release unit, but with additional polymers integrated into the composition, or as coatings over the pellet or granule.

Materials that can be used to obtain a delay in release suitable for this component of the invention can be, but are not limited to, polyethylene glycol (PEG) with molecular weight above 4,000 daltons (Carbowax, Polyox), waxes such as white wax or bees wax, paraffin, acrylic acid derivatives (Eudragit), propylene glycol, and ethylcellulose.

Typically these materials can be present in the range of 0.5–25% (W/W) of this component.

The Enteric Release Component

The components in this composition are the same as the immediate release component, but with additional polymers integrated into the composition, or as coatings over the pellet or granule.

The kind of materials useful for this purpose can be, but are not limited to, cellulose acetate pthalate, Eudragit L, and other pthalate salts of cellulose derivatives.

These materials can be present in concentrations from 4–20% (W/W).

The present invention will be described with respect to the following examples; however, the scope of the invention is not to be limited thereby. Unless otherwise stated, all parts and percentages set forth in this specification are by weight.

1 Beta Lactam Antibiotic and Beta-Lactamase Inhibitor Matrix Pellet Formulation and Preparation Procedure

45.1 Pellet Formulation

The composition of the antibiotic or inhibitor matrix pellets provided in Table 1.

*PVP K29/32 was added as a 20% W/W aqueous solution during wet massing.

45.2 Preparation Procedure for Antibiotic or Inhibitor Matrix Pellets

45.2.1 Blend antibiotic or inhibitor and Avicel® PH 101 using a Robot Coupe high shear granulator. 45.2.2 Add 20% Povidone K29/32 binder solution slowly into the powder blend under continuous mixing. 45.2.3 Extrude the wet mass using an LCI Bench Top Granulator. The diameter of the screen of the Bench Top Granulator was 1.0 mm. 45.2.4 Spheronize the extrudate using a Model SPH20 Caleva Spheronizer. 45.2.5 Dry the spheronized pellets at 50° C. overnight. 45.2.6 Pellets between 16 and 30 Mesh were collected for further processing. 45.2.7 The above procedure is used to prepare pellets that contain an antibiotic and pellets that contain an inhibitor.

45.3 Preparation of an Eudragit® L 30 D-55 Aqueous Coating Dispersion

45.3.1 Dispersion Formulation

The composition of the aqueous Eudragit L30D-55 dispersion applied to the antibiotic matrix pellets and to the inhibitor matrix pellets is provided below in Table 2.

45.4 Preparation Procedure for an Eudragit® L 30 D-55 Aqueous Dispersion

45.4.1 Suspend triethyl citrate and talc in deionized water. 45.4.2 The TEC/talc suspension is then homogenized using a PowerGen 700 high shear mixer. 45.4.3 Add the TEC/talc suspension slowly to the Eudragit® L 30 D-55 latex dispersion while stirring. 45.4.4 Allow the coating dispersion to stir for one hour prior to application onto the antibiotic matrix pellets.

45.5 Preparation of an Eudragit® S 100 Aqueous Coating Dispersion

45.5.1 Dispersion Formulation

The composition of the aqueous Eudragit® S 100 dispersion applied to the inhibitor matrix pellets is provided below in Table 3.

45.6 Preparation Procedure for an Eudragit® S 100 Aqueous Dispersion

Part A: 45.6.1 Dispense Eudragit® S 100 powder in deionized water with stirring. 45.6.2 Add ammonium hydroxide solution drop-wise into the dispersion with stirring. 45.6.3 Allow the partially neutralized dispersion to stir for 60 minutes. 45.6.4 Add triethyl citrate drop-wise into the dispersion with stirring. Stir for about 2 hours prior to the addition of Part B. Part B: 45.6.5 Disperse talc in the required amount of water 45.6.6 Homogenize the dispersion using a PowerGen 700D high shear mixer. 45.6.7 Part B is then added slowly to the polymer dispersion in Part A with a mild stirring.

45.7 Coating Conditions for the Application of Aqueous Coating Dispersions

The following coating parameters are used for coating with each of the Eudragit® L 30 D-55 and Eudragit® S 100 aqueous film coatings.

45.8 Encapsulation of the Antibiotic and Inhibitor Pellets

Pellets are filled into size 00 hard gelatin capsules at a ratio of 20%: 30%: 20%: 30% Immediate-release matrix pellets (uncoated), L30 D-55 coated pellets 12% weight gain, L30D-55 coated pellets 30% weight gain and S100 coated pellets respectively. The capsule is filled with the four different pellets to achieve the desired dosage.

The immediate release pellets contain the antibiotic; the L30 D-55 12% weight gain coated pellets contain the inhibitor; the L30 D-55 30% weight gain coated pellets contain the antibiotic and the S100 coated pellets contain the inhibitor.

The present invention is advantageous in that the beta-lactamase inhibitor will be dosed at a lower peak concentration, giving rise to fewer side effects. The alternative dosing of the antibiotic and the inhibitor will alternate the exposure to the bacteria in such a way as to make the antibiotic more effective than if they were co-administered, and thereby competing with each other for sites on the bacterial cell wall receptors.

Numerous modifications and variations of the present invention are possible in light of the above teachings, therefore, within the scope of the appended claims, the invention may be practiced otherwise than as particularly described.