NZ554077A

NZ554077A - Compositions containing piperacillin, tazobactam and a aminocarboxylic acid in sodium lactate diluent

Info

Publication number: NZ554077A
Application number: NZ554077A
Authority: NZ
Inventors: Jonathan Marc Cohen; Syed M Shah; Mahdi Fawzi
Original assignee: Wyeth Corp
Priority date: 2004-09-22
Filing date: 2005-10-12
Publication date: 2009-10-30

Abstract

Disclosed is a pharmaceutical composition comprising piperacillin, tazobactam, an aminocarboxylic acid, and a buffer in a sodium lactate diluent. Further disclosed is the use of the composition for the manufacture of a medicament for the treatment of conditions such as bacterial infection, burn, trauma and haemorrhage.

Description

New Zealand Paient Spedficaiion for Paient Number 554077 554007 COMPOSITIONS CONTAINING PIPERACILLIN, TAZOBACTAM AND A AMINOCARBOXILIC ACID IN A SODIUM LACTATE DILUENT FIELD OF THE INVENTION The invention relates to a pharmaceutical composition comprising piperacillin, tazobactam, an aminocarboxyiic acid, and a buffer in a sodium lactate diluent. The invention further relates to a method of treating a bacterial infection and an LR condition in a human which comprises administering to said human an effective 10 amount of a pharmaceutical composition comprising piperacillin, tazobactam, an aminocarboxyiic acid, and a buffer in a sodium lactate diluent.

BACKGROUND OF THE INVENTION Zosyn® is an antibiotic marketed product containing piperacillin sodium and tazobactam sodium. As listed on the label, Zosyn® is incompatible with lactated Ringer's solution.

There is a need for a pharmaceutical composition which overcomes the incompatibility of Zosyn© with lactated Ringer's solution.

BRIEF SUMMARY OF THE INVENTION The invention provides a pharmaceutical composition comprising piperacillin, tazobactam, an aminocarboxyiic acid and a buffer in a sodium lactate diluent.

The invention further provides a method of treating a bacterial infection and an LR condition in a human which comprises administering to said human an effective amount of a pharmaceutical composition comprising piperacillin, tazobactam, an aminocarboxyiic acid and a buffer in a sodium lactate diluent.

In some embodiments of the invention, an aminocarboxyiic acid is preferably EDTA. In some embodiments of the invention, the buffer is citric acid, preferably sodium citrate. 554007 In further embodiments of the invention, the sodium lactate diluent is lactated Ringer's solution.

In some embodiments of the invention, the sodium lactate diluent is Hartrnann's 5 solution.

DETAILED DESCRIPTION OF THE INVENTION The pharmaceutical compositions of the invention have the advantage over marketed pharmaceutical compositions of piperacillin-tazobactam wherein a solution for infusion of piperacillin-tazobactam in a sodium lactate solution, in particular lactated Ringer's solution or Hartrnann's solution demonstrate compatibility by having particulate counts not more than 6000 particles > 10 pm and not more than 600 particles > 25 pm and a chemical potency greater than 90% of the initial concentration. Compatibility for example with lactated Ringer's solution may be achieved by buffering the pharmaceutical compositions of the invention with a buffer, for example, citrate to maintain the suitable pH range of about 6.0 to about 7.5 in the presence of an aminocarboxyiic acid or a salt thereof. A preferred pH is about 6.5.

In an embodiment of the invention the aminocarboxyiic acid is EDTA in the form of edetate disodium dihydrate. Optionally the aminocarboxyiic acid may be added in a hospital setting before administration to a patient or may also be premixed in a ready-to-use pharmaceutical composition.

In particular, in a hospital setting, the compositions of piperacillin-tazobactam of the invention in the presence of a buffer and an aminocarboxyiic acid may be advantageously added to a human patient via a "Y" site connection on an intravenous line. A "Y" site connection is a common practice which permits additional medicaments to be added while a therapeutic infusion is in progress.

The following definitions are used throughout the application. 554007 "LR condition" means any condition which calls for the use of a sodium lactate diluent which include lactated Ringer's solution or Hartrnann's solution or other similar sodium lactate solution. Typical non-limiting LR conditions include burns, replacement of fluid deficits, trauma, blood substitutes, haemorrhage, infections and 5 the like. Optionally, Hartrnann's solution may replace lactated Ringe-'s.

"Treating" refers to reversing, alleviation of symptoms or inhibiting the progress of a bacterial infection.

" Diluent" means the fluid for administration to a patient, such as via parenteral (e.g., subcutaneous, intravenous, bolus injection, intramuscular, or intraarterial) administration. In particular diluents are a sodium lactate diluent more preferably lactated Ringer's solution or Hartrnann's solution. Typically, the sodium lactate diluent is added by intravenous infusion. Typically lactated Ringer's solution is used 15 in the United States, and Hartrnann's solution is used in Europe.

"Administering" means a treatment process wherein an effective amount of a pharmaceutical composition of the invention is delivered to a human patient.

"Bacterial infection" is the proliferation of a bacteria pathogen caused by Gram-positive and/or Gram-negative bacteria.

"Effective amount" is an amount of a pharmaceutical composition of the invention, where upon administration is capable of reducing or preventing the proliferation of 25 bacteria or reducing the symptoms of the bacterial infection.

"HPLC" means high pressure liquid chromatography.

The term, "aminocarboxyiic acid " preferably includes: ethylenediaminetetraacetic 30 acid (EDTA) and salts thereof, for example, ethylenediaminetetraacetic acid, calcium disodium salt (preferably as the hydrate), dicalcium EDTA; ethylenediaminetetraacetic acid, diammonium salt (preferably as the hydrate); ethylenediaminetetraacetic acid, dipotassium salt (preferably as the dihydrate); 3 554007 ethylenediaminetetraacetic acid, disodium salt (preferably as the dihydrate and, if desired, as the anhydrous form); ethylenediaminetetraacetic acid, tetrasodium salt (preferably as the hydrate); ethylenediaminetetraacetic acid, tripotassium salt (preferably as the dihydrate); ethylenediaminetetraacetic acid, trisodium salt 5 (preferably as the hydrate) and ethylenediaminetetraacetic acid disodium salt, l/SP(preferably as the dihydrate). Other "aminocarboxyiic acids" include: for example, diethylenetriaminepentaacetic acid (DTPA), hydroxyethylenediaminetriacetic acid (HEDTA), nitrilotriacetic acid (NTA), 0,0'-bis(2-aminoethyl)ethyleneglycol-N,N,N',N'-tetraacetic acid (EGTA), trans-1,2-10 diaminocyclohexane-N,N,N',N'-tetraacetic acid (CyDTA) or a pharmaceutical^ acceptable salt thereof (normally as a sodium salt).

"Aminoglycoside antibiotics" are selected from amikacin and tobramycin.

The terms Compound Sodium Lactate Infusion, European Lactated Ringer's Solution, and Hartman's Solution are used interchangeably.

Ingredient Compound Sodium Lactate Infusion BP (% w/v) Lactated Ringer's Injection USP (% w/v) Sodium 0.27 - 0.32 0.285-0.315 Potassium 0.019-0.022 0.0142-0.0173 Calcium Chloride dihydrate 0.025 - 0.029 0.018-0.022 Lactate 0.23 -0.28 0.231 - 0.261 Total Chloride 0.37 - 0.42 0.368 - 0.408 pH .0-7.0 6.0-7.5 Piperacillin sodium is the preferred form of piperacillin in the compositions of the present invention. Piperacillin free acid is a possible source of piperacillin for use in 20 making the compositions of the present invention. The free acid may be converted to the sodium salt during the formulation process. Piperacillin sodium is derived from D(-)- a-aminobenzylpenicillin. The chemical name of piperacillin sodium is sodium (2S, 5R, 6R)-6-[(R)-2-(4-ethyl-2,3-dioxo-1- piperazinecarboxamido)-2-phenylacetamido]-5 3,3-dimethyl-7-oxo-4-thia-1- azabicyclo(3.2.0) heptane-2- 4 554007 carboxylate, with a chemical formula of C23H26N507SNa and a molecular weight of 539.6.

Tazobactam sodium is the preferred form of tazobactam in the compositions of the 5 present invention. Tazobactam free acid is a possible source of tazobactam for use in making the compositions of the present invention. The free acid may be converted to the sodium salt during the process of forming the pharmaceutical compositions of the invention. Tazobactam sodium, a derivative of the penicillin nucleus, is a penicillanic acid sulfone. Its chemical name is sodium (2S, 3S, 5R)-3-methyl-7-oxo-3-10 (1H-1, 2, 3 -triazol-1 -ylmethyl)-4- thia-1-azabicyclo-(3,2,0)heptane-2-carboxylate-4, 4-dioxide. The chemical formula for tazobactam sodium is C^H^N 4Na05S and the molecular weight is 322.3.

The pharmaceutical compositions of the invention may be buffered with citrate or 15 other suitable buffers to maintain the pH within the preferred range of about 6.0 to about 7.5. Citrate is the preferred buffer because it can maintain the pH of the solution without significant drug degradation. The addition of a buffer is desired for controlling the pH to enhance stability. Preferably, a suitable amount of sodium citrate used to buffer the formulation, controls the pH for maximum stability without 20 significantly catalyzing or degrading the drug, or causing pain to the patient upon infusion. Sodium citrate dihydrate is the preferred form for the buffer used in the present invention. As used herein citrate is citric acid or salts thereof, preferably sodium citrate. Sodium citrate is available as trisodium citrate anhydrous, trisodium citrate dihydrate, and trisodium citrate pentahydrate. Sodium citrate dihydrate is also 25 known as trisodium citrate dihydrate and is preferred. The preferred form is trisodium citrate dehydrate. There are also several hydration forms of monobasic and dibasic sodium citrate which may replace the trisodium citrate, in whole or in-part.

Typical pharmaceutical compositions of the invention include the following ranges: 30 Piperacillin in the range of about 8 mg/ml to about 500 mg/ml; more preferably about 12 mg/ml to about 300 mg/ml; Tazobactam in the range of about 0.1 mg/ml to about 125 mg/ml; more preferably about 1.5 mg/ml to about 75 mg/ml; 554007 Citrate in the range of about 0.25 mg/ml to about 25 mg/ml; more preferably about 0.6 mg/ml to about 15 mg/ml; An aminocarboxyiic acid in the range of about 0.002 mg/ml to about 10 mg/ml; more preferably about 0.003 to about 1 mg/ml; Optionally added to pharmaceutical compositions of the invention is dextrose in the range of about 5 mg/ml to about 100 mg/ml.

Optionally added to pharmaceutical compositions of the invention are aminoglycosides in the range of about 0.1 mg/ml to about 75 mg/ml.

EXPERIMENTAL METHODS Determination of Piperacillin, and Tazobactam in typical pharmaceutical compositions of the invention A typical pharmaceutical composition of the invention, having 3000 mg/vial of piperacillin, 375 mg of Tazobactam, 150 mg of citrate and 0.75 mg of EDTA was reconstituted with 15 ml of sterile water for injection. The resulting solution was transferred to a flexible container containing 250 ml of Lactated Ringer's Solution, USP (United States Pharmacopeia). The container was mixed with gentle inversions 20 forming the drug solution and sampled immediately for chemical analysis. The container was then stored at ambient temperature for 24 hours and re-sampled. This test was performed in duplicate.

The chemical analysis was performed according to the following analytical method. 25 The analytical procedure is summarized as follows: 1) 4 ml aliquots of the drug solution is drawn and transferred to a 250 ml volumetric flask. 2) The flask is filled, qs. to 250 ml with dilution solvent (25% acetonitrile/75% 30 water, v/v) 3) Mixing is performed using gentle inversions of the flask. 4) Aliquots are then taken for HPLC analysis. 6 554007 WO 2006/044600 PCT/US2005/036938 ) The method further uses an isocratic flow of a mobile phase containing 25% acetonitrile/75% water, v/v. 6) The recommended column is a Phenomenex, Luna 3 micron Pheny-Hexyl 130 X 4.6 mm. 7) The UV absorbance detector is set at 210 nM. 8) Adjustments were made in calculations to compensate for volume overages in the Lactated Ringer's container (268 ml were found to be present).

A summary of the HPLC analysis data is provided as Table I.

Table I Typical Time Hr Piperacillin Tazobactam Total pharmaceutical (%LC) (%LC) Unidentified composition Degradants Sample 1a 0 119.1 115.0 0.1 % Sample 1 24 100.8 95.2 0.1% Sample 2 0 100.2 96.8 0.1% Sample 2 24 101.3 95.7 0.1% a) An investigation concluded that the cause of the higher than expected piperacillin and tazobactam result was due to a pipetting error.

A summary of the HPLC analysis data performed on a piperacillin / tazobactam formula without a buffer or an aminocarboxyiic acid using the analytical procedure for Samples 1 and 2 is provided in Table II. 7 WO 2006/044600 PCT/US2005/036938 Table II Typical Time Hr Piperacillin Tazobactam Total pharmaceutical (%LC) (%LC) Unidentified composition Degradants Sample 3 0 101.9 100.3 1.8% Sample 3 24 94.7 97.6 6.4% Sample 4 0 98.9 100.4 2.0% Sample 4 24 96.4 98.5 6.1% The compatibility of piperacillin-tazobactam vial products containing an 5 aminocarboxyiic acid and a buffer was evaluated in the presence of the compound sodium lactate to determine compatibility up to 24 hours at room temperature storage. Admixture samples were also tested for compatibility after being stored for 1 week under refrigerated (2-8°C) conditions. For these admixtures, the concentration tested was based on the commercially available volume (250 ml) of lactated Ringer's 10 solution.

Additional testing was performed which confirmed that admixture solutions prepared using reconstituted piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer that had been stored for not less than 48 hours at 15 refrigerated (2-8°C) conditions in the vial prior to admixing, demonstrated equivalent compatibility in this diluent.

Using the above test procedures, samples of each piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer concentration were 20 tested immediately (T=0 hour) after being admixed into the diluent. Remaining samples are stored at ambient laboratory conditions (about 20°C) and tested again 24 hours (T=24 hour) later. A set of samples were tested after 1 week under refrigerated (2-8°C) conditions. At all time points, the tests conducted included visual appearance and description, using the procedures described in USP <788> / 25 Ph. Eur. Chapter 2.9.19 Particulate Matter (Light Obscuration Particle Counts), and by HPLC chemical potency for Piperacillin and Tazobactam. 8 554007 All samples tested were determined to be clear and free of particulates by visual inspection. All particulate counts, were less than the USP/Ph. Eur. acceptance criteria of not more than 6000 particles >10 )jm and not more than 600 particles >25 5 ^im. As determined by HPLC, chemical potency was greater than 90% of the initial concentration.

The data in these studies demonstrated that piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer are compatible with compound 10 sodium lactate, for up to 24 hours when stored at room temperature for up to 1 week, when stored at refrigerated conditions (2-8°C) and that admixture dilutions may be prepared with reconstituted product stored at refrigerated conditions (2-8°C) in the vial for up to 48 hours.

Several standard tests were performed to evaluate the chemical and physical compatibility of piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer with a sodium lactate diluent. The first test was conducted to determine if piperacillin-tazobactam vial products containing an aminocarboxyiic acid 20 and a buffer are compatible in admixture with a sodium lactate diluent for up to 24 hours at room temperature storage. Admixtures were also tested after being held for 1 week under refrigerated (2-8°C) conditions. High (16 mg/ml, piperacillin; 2 mg/ml, tazobactam) and low (8 mg/ml, piperacillin; 1 mg/ml, tazobactam) concentrations of piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer 25 were prepared as admixtures with this diluent. They were based on a 250 mL bag.

In another standard test, a sodium lactate diluent was evaluated for compatibility with piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer as admixtures that were prepared using reconstituted drug product that had been 30 stored for not less than 48 hours at refrigerated (2-8°C) conditions prior to admixing. These admixtures were tested using the high and low concentrations described above. 9 554007 The following batches of piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer were used in the compatibility test procedures: a. 4.5 g/vial, Batch A9MY/1, manufactured by Wyeth. 5 b. 2.25 g/vial, Batch A9N3/1, manufactured by Wyeth.

The sodium lactate diluent used was Compound Sodium Lactate infusion, 500 mL containers, Lot 05E10D, manufactured by MacoPharma, Expiry Date 05/2007 Vial Reconstitution and Admixture Preparation Compound Sodium Lactate Each piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer were reconstituted at 5 ml of diluent per gram of piperacillin.

A sodium lactate was used to both reconstitute vials and subsequently prepare the 15 admixture solutions.

The admixtures were prepared to represent two vial strengths, lowest and highest piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer vial strengths (2.25g and 4.5g, respectively). The resultant admixture concentrations 20 evaluated are tabulated in Table III.

For a sodium lactate diluent, a 250 mL volume was used to prepare both the lowest and highest admixture concentration.

Admixture Testing Procedure In this study, samples of each piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer concentration were tested immediately (T=0 hour) after being admixed into the diluent lactated Ringer's solution. Remaining samples were stored at ambient laboratory conditions (about 20°C) and tested at and 24 hours (T=24 hour). A set of admixture samples were also tested after being stored 30 under refrigerated (2-8°C) conditions for 1 week. 554007 Analytical Test Methods The following test methods were used to analyze the samples. : HPLC Assay for Piperacillin and Tazobactam Visual Observation for Appearance and Description USP <788>/Ph. Eur. Chapter 2.9.19 Particulate Matter (Light Obscuration Method for sub-visible particulate counts) Acceptance Criteria All samples were visually clear and compliant with current USP/Ph. Eur. specification for subvisible particulates at T=0 hour, T=24 hours, and T=1 week under refrigerated (2-8°C) conditions (if applicable). For HPLC Assay, all samples after T=24 hours (or T= 1week under refrigerated (2-8°C) conditions) were not less than 90% of the initial 15 (T=0 hour) concentration for both piperacillin and tazobactam.

Particulate counts did not change as a function of time. The potencies were not substantially changed. There were no changes seen in any of product attributes over a 24 hour period.

Appearance and Description In the studies, the samples tested were determined to be clear and free of particulates by visual inspection. There were no differences observed in the diluent with piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a 25 buffer over a 24 hour admixture testing period.

Sub-Visible Particulate Matter All sub-visible particulate counts were acceptable, indicating no significant formation of particulates. All particulate counts, both at T=0 hour and T=24 hours were well 30 under the USP/Ph. Eur. acceptance criteria of less than 6000 particles a10 ^m and less than 600 particles >25 fim. There were no differences observed in the various diluents with piperacillin-tazobactam vial products containing an aminocarboxyiic acid 11 554007 and a buffer over the 24-hour admixture testing period. Results are presented in Table IV.

Potency In the tests, all HPLC chemical potency data for Piperacillin and Tazobactam met the acceptance criteria of not less than 90% of the initial concentration and remained unchanged over the 24-hour admixture testing period.

Acceptable physical stability (i.e. Appearance and Description and Sub-Visible 10 Particulates) and potency stability for admixtures prepared in the diluents, when stored at ambient conditions (about 20°C) for up to 24 hours after admixture preparation: Sodium Lactate Intravenous Infusion 15 Acceptable physical stability (i.e. Appearance and Description and Sub- Visible Particulates) and potency stability for admixtures prepared in this same diluent, but with reconstituted product stored at refrigerated conditions (2-8°C) for up to 48 hours. In addition, these admixtures demonstrated compatibility when stored at ambient conditions (about 20°C) for up to 24 hours after admixture preparation.

Table III Admixture Concentrations Used To Determine Compatibility of Piperacillin-Tazobactam Vial Products Containing An Aminocarboxyiic acid and a Buffer With Lactated Ringer's Intravenous Diluents Compatibility Study Name Reconstitution Diluent Admixture Diluent piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer Admixture Concentration Lactated Ringer's Preliminary Study Lactated Ringer's Injection-USP Lactated Ringer's Injection-USP LOW 8 mg/mL piperacillin; 1 mg/mL tazobactam HIGH 16 mg/mL piperacillin; 2 mg/mL tazobactam 12 554007 Table IV piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer Admixture Concentration USP/Ph. Eur Particulate Counts HPLC Potency Assay |W |am2 Piperacillin3 Tazobactam3 t=0 t=24 t=0 T=24 t=24 t=24 LOW 8 mg/mL piperacillin; 1 mg/mL tazobactam 1947 970 1243 1057 1407 873 37 40 17 3 23 20 100.1 99.8 HIGH 16 mg/mL piperacillin; 2 mq/mL tazobactam 1107 3217 3260 2083 2550 1770 17 153 70 87 97 47 100.4 100.1 1 Not more than 6000 2 Not more than 600 3 Not less than 90% initial Further studies Additional studies to evaluate the chemical and physical compatibility of admixtures of piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer with the intravenous fluid Lactated Ringer's Injection-USP were performed.

The compatibility of piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer vial products was evaluated with Lactated Ringer's Injection-USP to determine if such admixture solutions are compatible up to 24 hours at room temperature storage. For Lactated Ringer's Injection, the concentration tested was based on the available volume (250 ml) of this solution that most closely 20 matched the volumes described in the current commercial product (50 - 150 ml).

An additional study was performed which confirmed that admixture solutions prepared using reconstituted drug product that had been stored for not less than 48 13 554007 hours at refrigerated (2-8°C) conditions in the vial prior to admixing, demonstrated equivalent compatibility the diluent.

Samples of each piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer were tested immediately (T=0 hour) after being admixed into the diluent. Remaining samples are stored at ambient laboratory conditions (about 20°C) and tested again 24 hours (T=24 hour) later. In the preliminary study, samples were also tested after 4 hours (T=4 hour) storage at ambient laboratory conditions (about 20°C). At all time points, the tests conducted included visual appearance and description, USP <788> / Ph. Eur. Chapter 2.9.19 Particulate Matter (Light Obscuration Particle Counts), and HPLC chemical potency for Piperacillin and Tazobactam.

In the studies, all samples tested were determined to be clear and free of particulates by visual inspection. All particulate counts, were well under the USP/Ph. Eur. acceptance criteria of not more than 6000 particles >10 p.m and not more than 600 particles >25 ^m. Likewise, all HPLC chemical potency data met the acceptance criteria of not less than 90% of the initial concentration.

The data in these studies demonstrated that piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer is compatible admixture with lactated Ringers solution tested for up to 24 hour when stored at room temperature, that admixture dilutions may be prepared with reconstituted product stored at refrigerated conditions (2-8°C) in the vial for up to 48 hours, and that reconstitution of the piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer lyophilized dosage form with several preserved diluents had no impact on the compatibility and stability of the subsequent admixture prepared with saline.

Lactated Ringer's Study High and low concentrations of piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer were prepared as admixtures in Lactated Ringer's diluent. 14 554007 The compatibility up to 24 hours at room temperature storage of piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer in Lactated Ringer's Injection-USP was determined. High and low concentrations of piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer were 5 prepared as admixtures in the diluent and the Lactated Ringer's Injection, is based on a 250 mL bag.

Reconstituted Product Hold Time Prior to Admixture Study In this study, the diluents were evaluated for compatibility with piperacillin-10 tazobactam vial products containing an aminocarboxyiic acid and a buffer and were also prepared in highest and lowest admixture concentrations. However, in this study, the admixtures were prepared using reconstituted drug product that had been stored for not less than 48 hours at refrigerated (2-8°C) conditions prior to admixing.

MATERIALS AND METHODS Materials The following batches of piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer were used in the compatibility studies: 20 a. 4.5 g/vial, Batch A93374, manufactured by Wyeth, on 8 Sep 2004. b. 2.25 g/vial, Batch A87605, manufactured by Wyeth, on 6 Jul 2004. c. 40.5 g/vial, Batch A98715, manufactured by Wyeth, on 17 Sep 2004.

The following lots of intravenous diluents were used in one or more of the 25 compatibility studies described.

Lactated Ringer's Injection, USP, 250 mL containers, Lot J4J577, manufactured by B. Braun, Expiry Date 01/06 554007 Methods Vial Recoristitution and Admixture Preparation Each piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a 5 buffer were reconstituted at 5 ml of diluent per gram of piperacillin.

The admixtures for the studies were prepared with diluent to represent the lowest and highest piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer vial strengths {2.25g and 4.5g, respectively). The resultant admixture 10 concentrations evaluated in each of the studies are tabulated in Tables V-X.

For Lactated Ringers Injection, a 250 mL volume was used to prepare both the lowest and highest admixture concentration, as this is the smallest volume container available.

For Lactated Ringer's Injection-USP, low and high concentrations were prepared based on the lowest and highest piperacillin-tazobactam vial strengths (respectively) dissolved in 250 mL of this diluent.

Admixture Testing Procedure In the Lactated Ringer's Preliminary Study, samples of each piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer concentration were tested immediately (T=0 hour) after being admixed into the diluent. Remaining samples were stored at ambient laboratory conditions (about 20°C) and tested at 4 25 hours (T=4 hour) and 24 hours (T=24 hour).

Analytical Test Methods The following test methods were used to analyze the samples in these compatibility studies: HPLC Assay for Piperacillin and Tazobactam 16 554007 Visual Observation for Appearance and Description USP <788>/Ph. Eur. Chapter 2.9.19 Particulate Matter (Light Obscuration Method for sub-visible particulate counts) Acceptance Criteria All samples should be visually clear and compliant with current USP/Ph. Eur. specification for subvisible particulates at T=0 hour, T=4 hours (if applicable) and T=24 hours. For HPLC Assay, all samples after T=24 hours should not be not less 10 than 90% of the initial (T=0 hour) concentration for both piperacillin and tazobactam.

RESULTS The USP <788>/Ph. Eur. Chapter 2.9.19 and HPLC Assay data obtained for each diluent in each of the studies are provided in Tables V to X. Acceptance criteria were 15 met in all studies. Particulate counts did not change as a function of time in each solution in the chart. The potencies were not substantially changed.

DISCUSSION There were no changes seen in any of product attributes over a 24 hour period. The 20 results of these studies indicate acceptable stability.

Appearance and Description In all four studies, the samples tested were determined to be clear and free of particulates by visual inspection. There were no differences observed in the diluent 25 with piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer over a 24 hour admixture testing period.

Sub-Visible Particulate Matter In all four studies, all sub-visible particulate counts were acceptable, indicating no 30 significant formation of particulates. All particulate counts, both at T=0 hour, T=4 hours (where applicable) and T=24 hours were well under the USP/Ph. Eur. acceptance criteria of not more than 6000 particles >10 |im and not more than 600 17 554007 particles >25 ^m. There were no differences observed in the various diluents with piperacillin-tazobactam vial products containing an aminocarboxyiic acid and a buffer over the 24-hour admixture testing period.

Potency In the studies, all HPLC chemical potency data for Piperacillin and Tazobactam met the acceptance criteria of not less than 90% of the initial concentration and remained unchanged over the 24-hour admixture testing period.

Acceptable physical stability (i.e. Appearance and Description and Sub-Visible Particulates) and potency stability for admixtures prepared in the diluent Lactated Ringer's Injection, USP, when stored at ambient conditions (about 20°C) for up to 24 hours after admixture preparation.

Acceptable physical stability (i.e. Appearance and Description and Sub-Visible Particulates) and potency stability for admixtures prepared in these same diluent, but with reconstituted product stored at refrigerated conditions (2-8°C) for up to 48 hours. In addition, these admixtures demonstrated compatibility when stored at ambient conditions (about 20°C) for up to 24 hours after admixture preparation.

Acceptable physical stability (i.e. Appearance and Description and Sub-Visible Particulates) and potency stability for piperacillin-tazobactam reconstituted with each of the following preserved diluents and then further diluted in 0.9% Sodium Chloride Injection USP. In addition, these admixtures demonstrated compatibility when stored at ambient conditions (about 20°C) for up to 24 hours after admixture preparation.

The data also demonstrates that the product is compatible with Lactated Ringer's Injection, USP. 18 T able V Admixture Concentrations Used To Determine Compatibility of Piperacillin Tazobactam With Various Reconstitution and Intravenous Diluents Compatibility Study Name Reconstitution Diluent Admixture Diluent piperacillin-tazobactam Admixture Concentration Lactated Ringer's Preliminary Study Lactated Ringer's Injection-USP Lactated Ringer's Injection-USP LOW 8 mg/mL piperacillin; 1 mg/mL tazobactam HIGH 16 mg/mL piperacillin; 2 mg/mL tazobactam 19 o Table VI ~ O C\ Results for Lactated Ringer's Preliminary Study Reconstitution and Admixture Diluent Piperacillin-tazobactam Admixture Concentration USP/Ph. Eur Particulate Counts HPLC Potency Assay 10jim1 ^m2 Piperacillin3 Tazobactam3 t=0 t=4 t=24 t=0 t=4 t=24 t=0 t=24 t=0 t=24 Lactated Ringer's Injection-USP LOW 8 mg/mL piperacillin; 1 mg/mL tazobactam 2320 NT 560 50 NT 0 100% 101.3% 100% 99.6% HIGH 16 mg/mL piperacillin; 2 mg/mL tazobactam 2830 2440 2100 80 110 80 100% 100%a 98.6% 101.5%a 100% 100%a 97.9 100%a 1 Not more than 6000 2 Not more than 600 3 Not less than 90% initial ha O H e 'Jt CN Table VII Results for Unpreserved Diluents Study Reconstitution and Admixture Diluent Piperacillin-Tazobactam Admixture Concentration USP/Ph. Eur Particulate Counts HPLC Potency Assay (^m1 nm2 Piperacillin3 Tazobactam3 t=0 t=24 t=0 t=24 t=24 t=24 Lactated Ringer's Injection-USP LOW 8 mg/mL piperacillin; 1 mg/mL tazobactam 325 480 475 260 175 310 0 0 5 0 100% 99.4% HIGH 16 mg/mL piperacillin; 2 mg/mL tazobactam 625 1290 560 670 985 535 50 10 10 5 99.7% 100% 1 Not more than 6000 2 Not more than 600 3 Not less than 90% initial 21 Table VIII Results for Reconstituted Product Hold Time Prior to Admixture Study Reconstitution and Admixture Diluent Piperacillin-Tazobactam Admixture Concentration USP/Ph. Eur. Particulate Counts HPLC Potency Assay |^m1 ^m2 Piperacillin3 Tazobactam3 t=0 t=24 t=0 t=24 t=24 t=24 Lactated Ringer's Injection-USP LOW 8 mg/mL piperacillin; 1 mg/mL tazobactam 950 990 1645 975 1595 865 15 35 40 140 55 100.66 101.34 HIGH 16 mg/mL piperacillin; 2 mg/mL tazobactam 1245 1600 360 350 370 345 35 15 20 98.79 100.11 1 Not more than 6000 2 Not more than 600 3 Not less than 90% initial 22

Claims

WO 2006/044600 554007 PCT/US2005/036938 Table IX Results for European Lactated Ringer's Study from Refrigerated Concentrate Piperaciilin-Tazobactam Admixture USP / Ph. Eur. Particulate Counts HPLC Potency Assay 10nm1 25mm2 Piperacillin3 Tazobactam3 Concentration t=0 t=24 t=0 t=24 t=24 t=24 LOW 547 1340 0 27 8 mg/mL piperacillin; 520 377 3 17 96.4 96.5 1 mg/mL tazobactam 447 910 23 70 HIGH 687 893 47 20 16 mg/mL piperacillin; 1580 970 60 83 100.2 100.1 2 mg/mL tazobactam 1810 773 47 37 1 Not more than 6000 2 Not more than 600 5 3 Not less than 90% initial Table X Results for European Lactated Ringer's 1 Week Refrigerated Study Piperacillin-T azobactam Admixture Concentration USP / Ph. Eur. Particulate Counts HPLC Potency Assay 10|im1 25|nm2 Piperacillin3 Tazobactam3 t=1 week t=1 week t=1 week T=1 week LOW 8 mg/mL piperacillin; 1 mg/mL tazobactam 677 367 667 47 13 3 95.1 95.7 HIGH 1270 157 16 mg/mL piperacillin; 1433 37 98.6 99.1 2 mg/mL tazobactam 1013 20 1 Not more than 6000 2 Not more than 600 10 3 Not less than 90% initial 23 WO 2006/044600 554007 PCT/US2005/036938 WHAT IS CLAIMED IS:

1. A pharmaceutical composition which comprises piperacillin, tazobactam, an aminocarboxyiic acid and a buffer in a sodium lactate diluent.

2. The pharmaceutical compositon according to claim 1, wherein the sodium 5 lactate diluent is lactated Ringer's solution.

3. The pharmaceutical composition according to claim 1, wherein the sodium lactate diluent is Hartrnann's solution.

4. The pharmaceutical composition according to any one of claims 1 to 3 wherein the buffer is citric acid or a salt thereof. 10

5. The pharmaceutical composition according to claim 4, wherein the buffer is sodium citrate.

6. The pharmaceutical composition according to claim 4 or claim 5 in which the citrate is in the range of about 0.25 mg/ml to about 25 mg/ml.

7. The pharmaceutical composition according to claim 4 or claim 5 in which the 15 citrate is in the range of about 0.6 mg/ml to about 15 mg/ml.

8. The pharmaceutical composition according to any one of claims 1 to 7 wherein the pH is about 6.5.

9. The pharmaceutical composition according to any one of claims 1 to 8, wherein the aminocarboxyiic acid is EDTA or a salt thereof. 20

10. The pharmaceutical composition according to claim 9, wherein the salt of EDTA is selected from calcium disodium salt, dicalcium salt, diammonium salt, dipotassium salt, disodium salt, tetrasodium salt, tripotassium salt, and trisodium salt.

11. The pharmaceutical composition according to any one of claims 1 to 8, 25 wherein the aminocarboxyiic acid is selected from diethylenetriaminepentaacetic acid (DTPA), hydroxyethylenediaminetriacetic acid (HEDTA), nitrilotriacetic acid (NTA), 0,0'-bis(2- 24 WO 2006/044600 554007 PCT/US2005/036938 aminoethyl)ethyleneglycol-N,N,N',N'-tetraacetic acid (EGTA), and trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CyDTA) or a pharmaceutically acceptable salt thereof.

12. The pharmaceutical composition according to any one of claims 1 to 11, in 5 which the aminocarboxyiic acid is present in the range of about 0.002 mg/ml to about 10 mg/ml.

13. The pharmaceutical composition according to any one of claims 1 to 11, in wihich the aminocarboxyiic acid is present in the range of about 0.003 to about 1 mg/ml. 10

14. The pharmaceutical composition according to any one of claims 1 to 13, wherein the piperacillin is present in the range of about 8 mg/ml to about 500 mg/ml.

15. The pharmaceutical composition according to any one of claims 1 to 13, wherein the piperacillin is present in the range of about 12 mg/ml to about 300 15 mg/ml.

16. The pharmaceutical composition according to any one of claims 1 to 15, wherein the tazobactam is present in the range of about 0.1 mg/ml to about 125 mg/ml.

17. The pharmaceutical composition according to any one of claims 1 to 15, 20 wherein the tazobactam is present in the range of about 1.5 mg/ml to about 75 mg/ml.

18. The pharmaceutical composition according to any one of claims 1 to 17, which further comprises an aminoglycoside.

19. The pharmaceutical composition according to claim 18, wherein the 25 aminoglycoside is amikacin.

20. The pharmaceutical composition according to claim 18, wherein the aminoglycoside is tobramycin. 25 554007

21. The pharmaceutical composition according to any one of claims 18 to 20, in which the aminoglycoside is present in the range of about 0.1 mg/ml to about 75 mg/ml.

22. Use of an effective amount of a pharmaceutical composition according to any one of claims 1 to 21 for the manufacture of a medicament for the treatment of a bacterial infection and an LR condition in a human.

23. The pharmaceutical composition according to claim 1, substantially as herein described with reference to any one of the Experimental Methods.

24. The pharmaceutical composition according to any one of claims 1 to 21, substantially as herein described.

25. The use according to claim 22 in which the pharmaceutical composition is substantially as herein described with reference to any one of the Experimental Methods.

26. The use according to claim 22, substantially as herein described with reference to any one of the Experimental Methods.

27. The use according to claim 22, substantially as herein described. INTELLECTUAL PROPERTY OFFICE OF N.Z. 24 SEP 2009 RECEIVED