OA17289A - Stable preservative-free mydriatic and antiinflammatory solutions for injection. - Google Patents

Abstract

The present invention relates to stable, preservative- and antioxidant-free liquid formulations of phenylephrine and ketorolac for injection.

Description

STABLE PRESERVATTVE-FREE MYDRIATIC AND ANTI-INFLAMMATORY SOLUTIONS FOR INJECTION

I. Field of the Invention

The présent invention relates to stable, preservative-free and antioxidant-free 5 liquid pharmaceutical formulations of ketorolac and phenylephrme for injection into intraocular ophthalmologic irrigation solutions.

Π. Background of the Invention

Ophthalmologic surgery often requires the use of a physiologie irrigation solution to protect and maintain the physiological integrity of intraocular tissues. 10 Examples of ophthalmologic surgical procedures typically requiring irrigation solutions include cataract extraction and lens replacement and refractive lens exchange procedures, comeal transplant procedures and vitreoretinal operations and trabeculectomy procedures for glaucoma. Throughout the intraocular surgery, a patient’s pupil must be sufïiciently dilated to permit a clear operative field and to 15 limit the trauma that can be associated with the procedure.

Pupil dilation (mydriasis) is typically achieved by dilating the eye preoperatively by topical administration of a mydriatic agent. Preoperatively applied mydriatic agents that may typically be administered include sympathomimetics, such as alpha-1 adrenergic receptor agonists, and anticholinergic agents, such as anti20 muscarinics. Anticholinergic agents may be selected when longer action is desired, because they provide both cycloplegia (paralysie of the ciliary muscle) and mydriasis, e.g., tropicamide exhibits a half-life of approximately 4-6 hours.

However, for many procedures, alpha-1 adrenergics will be preferred because they provide mydriasis but not cycloplegia. Alpha-1 adrenergics are thus shorter acting, causing mydriasis during a surgical procedure and allowing the pupil to retum to its normal state shortly after completion of the procedure.

During the surgery, as the tips of surgical tools are insertcd into the anterior chamber of the eye, the iris sphincter muscle tends to constrict (miosis), reducing the window defined by the pupil. If pupil diameter is not maintained adequately throughout the procedure, the’risk of injuring structures within the eye increases and the required operating time is often prolonged. Clinically significant réductions in pupil diameter are associated with an increase in procedure-related complications, inciuding posterior capsule tears, retained lens fragments and vitreous leaks.

Many ophthalmologic surgeons may incorporate epinephrine into the intraocular irrigation solution to assist in the maintenance of pupil dilation. Toxic anterior segment syndrome (TASS) is an acute, noninfectious inflammation of the anterior segment of the eye. TASS is a serions complication that can be associated with anterior segment eye surgery, most commonly cataract surgery. Various contaminants hâve been implicated as causes of TASS. The use of epinephrine inciuding preservatives in intraocular irrigation solutions is one of a number of factors that has been associated with incidences of TASS after cataract surgery. See, e.g., http77www.cdc.gov/mmwr/preview/mmwrhtml/mm5625a2.htm, accessed July 9, 2012. Even “preservative-free” epinephrine, meanîng epinephrine that does not include an antimicrobial agent, still includes sodium metabisulfîte as an antioxidant, which has also been implicated by ophthalmologists as associated with potential toxicity to the comeal endothélium (Slack, et al., A bisulfîte-free intraocular epinephrine solution, Am J OphthalmoL;l 10(1):77-82 (1990)).

Phenylephrine is another alpha-1 adrenergic agent that is sometimes administered topically prior to surgery to promote mydriasis, but is not approved in the United States in a preservative- and antioxidant-free form for single-use injection. Examples of approved phenylephrine HCL solutions include either 0.01% benzalkonium chloride (AK-DILATE™ from Akom, available in 2 ml and 5 ml plastic dropper bottles; from Falcon Pharmaceuticals and Alcon Laboratories in multi-use 3 ml and 5 ml dropper bottles) and a “preservative-free” formulation that does not include an antimicrobial preservative but that still includes 2 mg of sodium metabisulfîte as an antioxidant (Neo-Synephrine® from InterMed Medical Ltd., available in a spray bottle).

It is also désirable to reduce postoperative pain and irritation for patient comfort. Because of this, patients may be treated preoperatively or postoperatively with a nonsteroidal anti-inflammatory drug (NSAID). Although cataract surgery (for example) is typically not associated with a high degree of post-operative pain, there 5 is a need to minimize the number of those patients in the minorîty who do expérience more severe post-operative pain. This is significant both because such patients expérience dîscomfort and may hâve concem that their procedure did not go well, and because patients may need to reexamined as a précaution to ensure that there is not a serious complication leading to the pain.

Various methods of deliveiy of ocular drugs, such as NSAIDs, are conventionally employed, each of which has limitations. These limitations may include comeal and conjuctival toxicity, tissue injury, globe perforation, optic nerve trauma, central retinal artery and/or vein occlusion, direct retinal drug toxicity, and systemic side effects. For example, topical médications applied drop-wise are frequently impeded in reaching a targeted ocular site due to the eye’s natural protective surface. In many situations, a rather small percentage of the médication applied to the surface of the eye will actualty reach the desired therapeutic site of action.

To achieve sufficient concentration of drug delivered to the back of the eye, drugs such as NSAIDs are frequently administered systemically at veiy high doses. These levels are necessary to overcome the blood-retina barrier that protects the back of the eye from selected drug molécules coming from the blood stream. For surgical procedures, injectable drug solutions are sometimes injected directly into the back of the eye. Subconjuctival and peribulbar periocular injections are used when higher local concentrations are needed and when drugs with poor pénétration characteristics need to be delivered. Intracameral injections directly into the anterior chamber are used in cataract surgery.

Ketorolac is an NSAID that is commercially available in preserved form for ocular use. Acular® from Allergan is a ketorolac tromethamine solution that 30 includes benzalkonium chloride 0.01% as a preservative, available in 3 ml and 6 ml dropper bottles. Bedford Laboratoires also supplies ketorolac tromethamine in a concentrated form (15 mg or 30 mg in 1 mL or 60 mg or 300 mg in 10 mL) for injection for intravascular or intramuscular administration. Allergan supplies a preservative-free 0.45% ketorolac tromethamine ophthalmic solution, which is 35 formulated with carboxymethylcellulose sodium, sodium chloride, sodium citrate dehydrate, in individual use vials under the tradename Acuvail®.

While intracameral injection provides a prompt method of achieving a concentration, it can be associated with comeal toxicity. However, this method • suffers from the fact that these drugs are quickly removed by the eye's natural circulatory process. Thus, injectable solutions rapidly lose their therapeutic benefit, often necessitating frequent, large dose injections that can cany toxicity risks. Sustained release formulations, such as viscoelastic gels containing microcapsules, may be injected intraoculariy for a longer duration of action. However, there may be some delay in reaching a local therapeutic concentration of drug. Hence, there exists a need for controlled methods of ocular delivery during ophthalmologic procedures.

Solutions that hâve been used in ophthalmologic surgical irrigation include normal saline, lactated Ringer’s solution and Hartmann’s lactated Rînger’s solution, but these are not optimal due to potential unfavorable comeal and endothélial effects. Other aqueous solutions that include agents such as etectiolytes, buffering agents for pH adjustment, glutathione and/or energy sources such as dextrose, better protect the tissues of the eye, but do not address other physiologie processes associated with surgery. One commonly used solution for ophthalmologic irrigation is a two part buffered electroiyte and glutathione solution disclosed in U.S. Patent 4,550,022 to Garabedian et al., the disclosurc of which is hereby exprcssly incorporated by reference. The two parts of this solution are mixed just prior to administration to ensure stability. These solutions are formulated with a goal of maïntaining the health of ocular tissues during surgery.

Another example of a modified solution is disclosed in International PCT Application WO 94/08602 in the name of inventors Gan et al., the disclosurc of which is hereby incorporated by reference. This application discloses the inclusion of a mydriatic agent, such as epinephrine, in ocular irrigation solutions. Still another example is provided by International PCT Application WO 95/16435 in the name of inventors Cagle et al., which discloses the inclusion of non-steroidal antiinflammatory drugs (NSAIDs) in an ophthalmologic irrigation solution.

ΠΙ. Summary of the Invention

The présent invention provides a stérile, preservative-free and antioxidantfree liquid formulation of a mydriatic agent, phcnylephrine, and an anti-inflammatory agent, ketorolac, for injection. The formulation can be suitably injected into an intraocular irrigation carrier and used to irrigate ocular tissues during surgery. The formulation avoids the potential toxicity that may be associated with preservatives and antioxidants yet has adéquate stability.

One embodiment of the invention provides a preservative-free and antioxidant-free stérile liquid pharmaceutical formulation including phenylephrine, ketorolac and a buffer system in an aqueous carrier, that is stable for at least six months when stored at a température of from 5+/-3°C to 25+/-2°C. Preferably, the 5 formulation is stable for a period of at least 24 months when stored at a température of from 5+/-3°C to 25+/-2°C.

In one aspect of the invention, the buffer system is selected from a sodium phosphate buffer System and a sodium citrate buffer system. Preferably the buffer system is a sodium citrate buffer System, such as an about 20 mM sodium citrate 10 buffer System. In another aspect of the invention, the formulation has a pH of from 5,8 to 6.8.

In another aspect of the invention, the formulation is contained within a single-use container, such as a vial that is closed with a closure through which an injection can be drawn and a pre-fiUed syringe.

A suitable formulation of the présent invention includes from 46 to 76 mM phenylephrine and from 8.5 to 14 mM ketorolac, and as one example may contain about 60.75 mM phenylephrine and about 11.25 mM ketorolac. The formulations of the présent invention may include phenylephrine and ketorolac at a molar ratio of from 1:1 to 13:1 phenylephrine to ketorolac, and suitably may include these agents at 20 a molar ratio of from 3:1 to 10:1 phenylephrine to ketorolac.

Another embodiment of the invention provides a preservative-free and antioxidant-free stérile liquid pharmaceutical formulation including phenylephrine, ketorolac and a buffer system in an aqueous carrier, and an întraocular irrigation carrier into which the formulation is injected, such that after injection the 25 phenylephrine is présent at a concentration of from 30 to 720 μΜ and the ketorolac is présent at a concentration of from 44 to 134 μΜ. In another aspect of the invention, after injection into an întraocular irrigation carrier the phenylephrine is présent at a concentration of fromn 240 to 720 μΜ and the ketorolac is présent at a concentration of from 10 to 270 μΜ.

Another embodiment of the invention provides a stérile liquid pharmaceutical formulation that consists essentially of phenylephrine, ketorolac and a buffer system in an aqueous carrier, wherein the formulation is stable for at least six months when stored at a température of from 5+/-3°C to 25+/-2°C. Preferably, the formulation is stable for a period of at least 24 months when stored at a température of from 5+/-3°C 35 to25+/-2°C.

In one aspect of the invention, the buffer System îs selected from a sodium phosphate buffer System and a sodium citrate buffer system. Preferably the buffer system is a sodium citrate buffer system, such as an about 20 mM sodium citrate buffer System. In another aspect of the invention, the formulation has a pH of from 5.8 to 6.8.

In another aspect of the invention, the formulation is contained within a single-use container, such as a vial that is closed with a stopper through which an injection can be drawn and a pre-fïlled syringe.

Another aspect of the invention provides a stérile liquid pharmaceutical dosage form for injection, including phenylephrine, ketorolac, a buffer system and an aqueous carrier, packaged in a single-use container for injection.

In another aspect of the invention, a stérile liquid pharmaceutical formulation is provided that includes phenylephrine, ketorolac, a buffer system and an intraocular irrigation carrier, in which the phenylephrine is included at a concentration of from 30 to 720 μΜ and the ketorolac is included at a concentration of from 10 to 270 μΜ, or preferably the phenylephrine is included at a concentration of from 90 to 720 μΜ and the ketorolac is included at a concentration of from 44 to 134 μΜ. This formulation may also be près ervative- free and antioxidant-free.

Also disclosed is a method of preparing a preservative-free and antioxidantfree stérile liquid pharmaceutical formulation including phenylephrine, ketorolac and a buffer System in an aqueous carrier, that is stable for at least six months when stored at a température of from 5+/-3°C to 25+/-2°C. Preferably, the formulation îs stable for a period of at least 24 months when stored at a température of from 5+/-3°C to25+/-2°C.

Further disclosed is a method of preparing a stérile liquid pharmaceutical formulation including phenylephrine, ketorolac, a buffer system and an intraocular irrigation carrier, in which the phenylephrine is included at a concentration of from 30 to 720 μΜ and the ketorolac is included at a concentration of from 10 to 270 μΜ, or preferably the phenylephrine is included at a concentration of from 90 to 720 μΜ and the ketorolac is included at a concentration of from 44 to 134 μΜ. This formulation may also be preservative-free and antioxidant-free.

IV. B rief Description of the Drawings

The présent invention will now be described in greater detail, by way of example, with reference to the accompanying drawings in which:

FIGURES 1-12 provide the results of a study of the stability of phenylephrine and ketorolac combination formulations at different time points over a 12 month period when stored at controlled températures from 2-8 °C to 60 °C, as determined by measurement of the percentage of related substances from dégradation of the 5 active phannaceutical ingrédients, with variables of concentration of the active pharmaceutical ingrédient concentrations, different buffer Systems, addition of the preservative EDTA and addition of the preservative EDTA plus the antioxidant sodium metabisulfite.

FIGURES 13-14 provide the results of a study evaluating the effect of a 10 nitrogen overlay on the stability of two phenylephrine and ketorolac combination formulations, with or without the preservative EDTA, at different time points over a one year period when stored at controlled températures from 4 °C to 60 °C.

FIGURES 15-18 provide the results of a study evaluating the effects of different antioxidants on the stability of a phenylephrine and ketorolac combination 15 formulation at time points over a one month period after storing samples at températures ranging from 2-8 °C to 60 °C.

FIGURE 19 provides the resuit of a study evaluating the stability of a high concentration phenylephrine formulation over a four month time period when stored at températures from 4 °C to 40 °C.

FIGURES 20A and 20B demonstrate the potency of phenylephrine and ketorolac, respectively, in phenylephrine and ketorolac combination formulation when stored for 30 months at 2-8°C.

FIGURES 21-25 illustrate the results of a non-human primate concentrationranging efficacy study evaluating phenylephrine and ketorolac when given 25 individually and when combined via intraocular irrigation in a balanced sait solution (BS S) during phacoémulsification lens extraction and exchange surgery, with measures of mydriasis (FIGURES 21 and 22) and flare (FIGURES 23-25) being observed.

FIGURES 26-28 illustrate the results of a non-human primate study 30 evaluating the effect of a phenylephrine and ketorolac combination formulation on mydriasis (FIGURE 26) and flare (FIGURES 27-28) when delivered via intraocular irrigation in BSS during phacoémulsification lens extraction and exchange surgery.

FIGURE 29 illustrâtes the results of a dose-ranging study evaluating different concentrations of a phenylephrine and ketorolac combination formulation on 35 mydriasis when delivered in BSS during phacoémulsification lens extraction and exchange surgery in a non-human primate.

V. Detailed Description

The présent invention provides stérile formulations of irrigation solutions for perioperative local application to ocular tissues, inciuding intraocular and topical application, that include phenylephrine as a mydriatic agent and ketorolac as an antiinflammatory agent These formulations are free of both preservatives and antioxidants, yet exhibit unexpectedly good stability. They are preferably packaged in single-use containers for injection and can be injected into a larger volume of an intraocular irrigation carrier prior to and used during intraocular procedures, such as cataract extraction and lens replacement and refractive lens exchange procedures.

Définitions

A “preservative” as used herein means an antimicrobîal agent that is added to a pharmaceutical product to maintaîn stability and prevent décomposition by microbial growth. Common antimicrobîal preservatives that may be included in a pharmaceutical compositions include sorbic acid and its salts, benzoic acid and its salts, calcium propionate, sodium nitrite (and sodium nitrate which couverts to sodium nitrite in situ), sulfites (sulfur dioxide, sodium bisulfite, potassium hydrogen sulfite, etc.) and the métal chelator sodium ethylenediamine tetraacetic acid, also referred to as edetate disodium, EDTA or Na₂ EDTA.

An “antioxidant” as used herein refers to a substance that preferentially reacts with oxygen and thereby protect a pharmaceutical product to which it is added from dégradation due to oxidation. Examples of water- or oil-soluble antioxidants that may be included in a pharmaceutical composition include sodium bisulphite, sodium sulphite, sodium metabisulphite, sodium thiosulphite, sodium formaldéhyde sulphoxylate, l- and d-ascorbic acid, acetylcysteine, cysteine, thioglycerol, thioglycollic acid, thiolactic acid, thieurea, dihithreitol, glutathione, propyl galtate, butylated hydroxyanisole, butylated hydroxytoluene, tertiary butyl hydroquinone, ascorbyl palmitate, nordihydroguaiaretic acid and alpha-tocopherol.

A “preservative-free” solution refers to a solution that does not include benzalkonium chloride or other antimicrobîal agent.

An “antioxidant-free” solution refers to a solution that does not include sodium metabisulfite or other agent that has been included for the sole function or serving as an antioxidant, though an antioxidant-free solution may include a pH buffering system, one component of which may hâve antioxidant activity.

-9“Ketorolac” means ketorolac in a sait form, such as ketorolac tromethamine [(+/-)-5-Benzoyl-2,3-dihydro-lH-pyrrolizme-l-carboxylic acid:2-amino2(hydroxymethyl)-l,3-propanediol (1:1)].

Phenylephrine” means phenylephrine În a sait form, such as phenylephrine 5 HCL [(-)-m-Hydroxy-a-[(methyl amino)methyl]benzyl alcohol hydrochloride].

“Related substances” with respect to a given pharmaceutical ingrédient refera to substances that resuit from dégradation of the ingrédient, expressed as a percentage of the total concentration of the pharmaceutical ingrédient in the formulation. As used herein with respect to the présent invention, “total related 10 substances” refera to the total of ail related substances resulting from dégradation of the active pharmaceutical ingrédients ketorolac and phenylephrine in the formulation, expressed as a percentage of the total concentration of the pharmaceutical ingrédient in the formulation. Any related substance that is présent at below the lower limit of quantitation, e.g., 0.1%, for the assay used to measure related substances is not 15 included in the summation in determining total related substances. In the figures accompanying the examples herein, reference to a 0% related substances for an ingrédient means that there were no related substances for the ingrédient that were présent at a level above the lower limit of quantitation, e.g., 0.1%, for the substance being assayed.

“Stable” refera to a liquid pharmaceutical formulation that, at the end of a specified storage period of time, contains less than 5% total related substances. In one embodiment, a stable liquid formulation is stable at a température from 5+/-3°C (i.e., 2-8 °C) to 25+/-2°C (i.e., 23-27 °C) for a period of at least six months. In a preferred embodiment, a stable liquid formulation is stable at a température from 5+/25 3°C to 25+/-2°C for a period of at least one year. In a preferred embodiment, a stable liquid formulation is stable at a température from 5+/-3°C to 25+/-2°C for a period of at least 24 months. In a preferred embodiment, a stable liquid formulation is stable at a température from 5+/-3°C to 25+/-2°C for a period of at least 30 months. In a preferred embodiment of the invention, the stable formulations of the invention hâve 30 less than 1.0% total related substances after a given storage period.

The term “about” is understood to mean that there can be variation in the concentration of a component of the described formulation that can be to 5%, 10%, 15% or up to and including 20% of the given value. For example, the phrase “a formulation having about 20 mM sodium citrate” is understood to mean that the 35 formulation can hâve from 16 mM to 24 mM sodium citrate.

The term “stérile” refera to a pharmaceutical product that has been aseptically processed and that is devoid of viable bacteria, fungi or other microorganisms.

Pharmaceutical Agents

This invention provides stable, liquid preservative-free and antioxidant-free pharmaceutical formulations of a combination of two active pharmaceutical ingrédients (APIs), phenylephrine as a mydriatic agent and the NSAID ketorolac as an anti-inflammatory agent

Ketorolac “Ketorolac” in the preferred formulation of the présent invention is included as the ketorolac tromethamine sait [(+/-)-5-Benzoyl-2,3-dihydro-lH-pyrTolizme-lcarboxylic acid:2-amino-2(hydroxymethyl)-l,3-propanediol (1:1)]. Ketorolac is a member of the pyrrolo-pyrrole group of nonsteroidal anti-inflammatory drugs. Ketorolac HCL is a racemic mixture of the R-(+) and S-(-) enantiomers that may exist in three crystal forms, ail of which are equally soluble in water. This agent discolors upon prolonged exposure to light and accordingly light shielded packaging (e.g., over-boxing or use of an amber vial) may be suitably utilized for packaging of formulations of the présent invention.

Phenylephrine “Phenylephrine” means phenylephrine in a sait form, such as phenylephrine HCL [(-)-m-Hydroxy-a-[(methyl amino)methyl]benzyl alcohol hydrochloride]. Phenylephrine is an alpha receptor sympathetic agonist Phenylephrine HCl is freely soluble in water and alcohol.

-nAqueous Carriers

The APIs are added to an aqueous solvent as a carrier, and the inventors hâve determined that no solubilizing agents are reqüjred. The aqueous carrier is suitably water for injection (WFI), which is a stérile, solute-free préparation of distilled water.

Altemately, other aqueous carriers that are not harmful to intraocular tissues and which would not adversely affect the stability of the formulation may be used, such as deionized water, or, after first evaluating for potential impact on stability, saline or a balanced sait solution such as that described below.

Buffering Systems

The formulation of the présent invention is adjusted to a pH from 5.8 to 6.8, and preferably to about 6.3. Sodium hydroxide and hydrochloric acid may be added as required to adjust the formulation to this pH. The desired pH is suitably maintained by use of a buffering system. One such suîtable system is a citrate buffer, including citric acid monohydrate and sodium citrate dehydrate, and another suîtable system is a sodium phosphate buffer, including dibasïc sodium phosphate and monobasic sodium phosphate. Either buffer system may be used at an appropriate concentration in the range of 10 mM to 100 mM, and suitably may be 20 mM. As described below in Example 1, sodium citrate is a preferred buffer for use in a preservative-free formulation. The citric acid in the citrate buffer, which has the 20 ability to chelate divalent cations and can thus also prevent oxidation, provides an antioxidant effect as well as a buffering effect. However, its presence does not dégradé stability, as did other antioxidants (Example 3 below). As used herein, the term “antioxidant free” precludes the use of other antioxidants but does not preclude the use of a buffering agent, such as citric acid, that is included as part of the buffering system.

No Other Excipients

In a further aspect of the invention, in addition to being free of any preservatives or antioxidants, a formulation in accordance with the présent invention also does not include any excipients other than the buffering system. For example, 30 no solubilizing agents, such as éthanol or éthanol, are used (i.e., the formulation is solubilizing-agent free.) Preferred formulations of the présent invention consist essentially of the two APIs and the buffering system in water for injection, yielding a very pure formulation with reduced potential for toxicity to intraocular tissues.

Single-Use Containers

In a further aspect of the invention, the phenylephrine and ketorolac combination formulation of the présent invention is contaîned in a quantîty sufficient for a single-use during intraocular surgery in a container that facilitâtes such singleuse and does not facilitate multi-use administration. Thus a sufficient quantity of drug composition formulated in accordance with the présent invention, that is equal to or just slightly more (i.e., not more than 25% excess) than the amount of the drug composition desired to be added to a standard container of intraocular irrigation carrier, is contaîned within a single use container that facilitâtes dispensing of the drug composition by injection. For example, the desired single-use quantity of phenylephrine and ketorolac combination drug composition may be packaged in a glass vial closed with a stopper or other closure that includes a septum through which a hypodermic needle may be inserted to withdraw the drug composition, or may be packaged in a prefilled syringe. One example of a suitable container and closure system is a 5 mL USP Type 1 borosilicate flint glass vial with a West 20-mm gray butyl stopper and a 20-mm flip-off seal.

Before closing the container it may be désirable, based on the results described in Example 2 below, for the drug composition formulated in accordance with the présent invention to be exposed to a nitrogen overtay (i.e., the displacement of air from the head space in the vial with nitrogen before sealing the vial). Other methods of evacuating air and displacing it with an inert gas may also be utilized, such as sparging an inert gas through the solution.

Intraocular Irrigation Carriers

The phenylephrine and ketorolac combination drug composition (i.e., combination drug product) is suitably added by injection into a bag, bottle or other container of an intraocular irrigation solution prior to administration by intraocular or topical irrigation or lavage. Suitable intraocular irrigation solutions include saline, lactated Ringer’s, balanced sait solution or any other irrigation solution that is compatible with the aqueous formulation and not harmful to ocutar tissues. One suitable intraocular irrigation carrier includes one or more, and preferably ali, of the following adjuvants: sufficient electrolytes to provide a physiological balanced sait solution; a cellular energy source; a buffering agent; and a free-radical scavenger. One suitable solution (referred to in the examples below as a “balanced sait solution” or “BSS” includes: electrolytes of from 50 to 500 millimolar sodium ions, from 0.1 to 50 millimolar potassium ions, from 0.1 to 5 millimolar calcium ions, from 0.1 to 5 millimolar magnésium ions, from 50 to 500 millimolar chloride ions, and from 0.1 to

millimolar phosphate; bicarbonate as a buffer at a concentration of from 10 to 50 millimolar, a cellular energy source selected from dextrose and glucose, at a concentration of from 1 to 25 millimolar, and glutathione as a free-radical scavenger (i.e., antioxidant) at a concentration of from 0.05 to 5 millimolar.

One example of a suitable method of diluting and administering the combination drug composition of the présent invention utilizes the formulation of the présent invention described as Formula 2 in Table 2 below. An aliquot of 4.5 mL of this solution, including 4.0 mL as the intended quantity for single use and 0.5 mL of overfîll, is contained within a stérile closed single-use vial and is intended for admixture with irrigation solution for administration during intraocular surgeiy. From the vial, 4 mL is withdrawn by syringe and mixed with 500 mL of BSS by injection into a 500 mL bag or bottle of BSS to provide a final concentration of 483 μΜ phenylephrine and 89 μΜ ketorolac tn the irrigation solution for local delivery to the eye.

In another aspect of the invention, a stérile liquid pharmaceutical formulation for irrigation may be provided in which the phenylephrine and ketorolac is already admixed within an intraocular irrigation carrier, such that it has been diluted to the concentration of each active pharmaceutical ingrédient desired for local delivery to intraocular tissues during surgeiy, and contained within a stérile bag, bottle or other single-use irrigation container. For example, such a formulation for irrigation may include phenylephrine at a concentration of from 30 to 720 μΜ and ketorolac at a concentration of from 10 to 270 μΜ, or preferably may include the phenylephrine at a concentration of from 90 to 720 μΜ and the ketorolac at a concentration of from 44 to 134 μΜ. In one embodiment, the phenylephrine and ketorolac combination is admixed within a balanced sait solution, such as that described above, as the intraocular irrigation carrier. This pharmaceutical formulation for irrigation may suitably be totally preservative-free and antioxidant-free, or optionally may include onîy an anti-oxidant that is typically included in the non-medicated intraocular irrigation carrier, such as the glutathione in the balanced sait solution described above, but no preservative.

Exemplary Formulations

As described above, the stable, liquid pharmaceutical formulations of the présent invention include phenylephrine and ketorolac in a buffered aqueous carrier. Suitable concentrations of phenylephrine in the combination drug compositions of the présent invention range from 10 mM to 500 mM, and preferably from 45 mM to 112 mM. Suitable concentrations of ketorolac in the combination drug compositions

-14of the présent invention range from 2 mM to 75 mM, and preferably from 8.5 mM to mM. The buffer system, such as a sodium citrate buffer system, is suitably included at a concentration of from 10 to 100 mM, and preferably at about 20 mM.

Two exemplary formulations in accordance with the présent invention are set forth in 5 Tables 1 and 2 below. In each case, sodium hydroxide and/or hydrochloric acid may be added when preparing the formulation if necessary to adjust the pH to about 6.3.

Table 1

Example Formulation 1

Component (USP) added to water for injection	Preferred Concentration	Suitable Concentrations	Représentative Diluted Doslng Concentration (μΜ)
	mg/ml	mM	mg/ml	mM	Preferred	Suitable
Phenylephrine HCl	18.33	90	13.7-22.9	68-112	720	360-1,080
Ketorolac tromethamine	424	1125	32-5.3	8.5-14	89	44-134
Citric acid monohydrate	024*		0.12- 120**
Sodium citrate dihydrate	5.48*		2.74- 27.4**

♦Corresponding to a 20 mM citrate buffer. •♦Corresponding to a lOmM to lOOmM citrate buffer.

Table 2

Example Formulation 2

Component (USP) added to water for injection	Preferred Concentration	Suitabie Concentrations	Représentative Diluted Dosing Concentration (μΜ)
	mg/ml	mM	mg/ml	mM	Preferred	Suitabie
Phenylephrine HCl	1237	60.75	9.2-15.5	45-76	483	240-720
Ketorolac tromethamine	4.24	11.25	3.2-53	8.5-14	89	44-134
Citric acid monohydrate	0.24*		0.12- 1.20**
Sodium citrate dihydrate	5.48*		2.74- 27.4**

* Correspondîng to a 20 mM citrate buffer.

** Correspondîng to a lOmM to lOOmM citrate buffer.

The amounts of pharmaceutically active ingrédients included in the formulation can be expressed in molar ratios. The molar ratio of phenylephrine to ketorolac may range from 1:1 to 13:1, and more suitably may range from 3:1 to 10:1. An exemplary molar ratio of phenylephrine and ketorolac as represented by Formula 10 1 in Table 1 above is 8:1 of phenylephrine to ketorolac. Another exemplary molar ratio of phenylephrine and ketorolac as represented by Formula 2 in Table 2 above is 5.4:1 of phenylephrine to ketorolac.

Following dilution of the formulation of the présent invention into an intraocular irrigation carrier for local delivery, the dosing concentration of 15 phenylephrine may be from 3 to 7,200 μΜ, more suitably from 30 to 720 μΜ, more preferably from 90 to 720 μΜ, still more preferably from 240 to 720 μΜ, and most preferably about 483 μΜ. Following dilution of the formulation of the présent invention into an intraocular irrigation carrier for local delivery, the dosing concentration of ketorolac may be from 3 to 900 μΜ, more suitably from 10 to 270 20 μΜ, more preferably from 44 to 134 μΜ, still more preferably from 30 to 90 μΜ, and most preferably about 90 μΜ.

Methods of use

The stable liquid formulations of the présent invention may be utilized after mixing with an intraocular irrigation carrier in a variety of ophthalmologic procedures. These include cataract extraction and lens replacement and refractive lens exchange procedures, comeal transplant procedures and vitreoretinal operations and trabeculectomy procedures for glaucoma.

One example of a suitable method of diluting and administering the combination drug composition of the présent invention utilizes the formulation of the présent invention described as Formula 2 in Table 2 above. A stérile, single-use 5 mL vial containing 4.5 mL of the composition in provided, from which 4 mL of the composition is withdrawn by syringe and mixed with 500 mL of BSS by injection into a 500 mL bag or bottle of BSS to provide a final concentration of 483 μΜ phenylephrine and 89 μΜ ketorolac. This solution is irrigated through the anterior chamber of the eye at a constant concentration throughout the procedure. As such, in this example, the drug product is only administered intracamerally during the procedure.

The active pharmaceutical agents are included at dilute concentrations in the intraocular irrigation carrier. The concentrations of the agents are determined in accordance with the teachings of the invention for direct, local application to ocular tissues during a surgical procedure. Application of the solution may be carried out perioperatively, i.e.: intra-operatively; pre- and intra-operatively; intra- and postoperativety; or pre-, intra- and post-operatively.

It must be noted that as used herein and in the appended claims, the singular forms a, and, and the include plural référents unless the context clearly dictâtes otherwise. Thus, for example, référencé to an excipient includes a plurality of such excipients and équivalents thereof known to those skilled in the art, and so forth.

The publications discussed herein are provided solely for their disclosure prior to the filing date of the présent application. Nothing herein is to be construed as an admission that the présent invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed. Ail citations are incoiporated herein by référencé.

EXAMPLES

Examples 1-5

In the studies described in the following Examples 1 - 5, the presence of related substances (RS) and potency was measured by high performance liquid

chromatography with UV detector (HPLC-UV) as an indication of stability, with an increase in the percentage of related substances detected indicating the presence of dégradation products. In these studies, the HPLC-UV utilized a Zorbax XDB-C8, 5 μΜ, 4.6 mm x 150 mm column with a flow rate of 1.2 ml/min. Mobile phases A and B were as follows: Mobile phase A: 650 mL of 1.1 mg/mL 1-octansulphonîc acid, pH 3.0:50 mL of Milli-Q water:300 mL methanol. Milli-Q water. 300 mL methanol; Mobile phase B: 300 mL of 1.1 mg/mL l-octansu!phonic acid, pH 3.0:50 mL of Milli-Q water:650 mL methanol. The diluent used was mobile phase A. A gradient of 100% A to 100% B in 40 minutes was used. A 280 nm UV detector was used.

Exampie 1

Comparlson of Stability of Formulations Depending on Use of a Preservative and an Antioxidant and Using Dlffering Buffer s.

A study was run to compare different formulations of combinations of two active pharmaceutical ingrédients (APIs), phenylephrine HCl (PE) and ketorolac tromethamine (KE), each at an equai concentration of either 5 mM or 1 mM in an aqueous solution. Two different buffering Systems were utilized to maintain the solution at three different pHs: a 20 mM sodium phosphate buffer (dibasic sodium phosphate and monobasic sodium phosphate) for a pH of 7.4; a 20 mM sodium citrate buffer (citric acid monohydrate and sodium citrate dehydrate) for a pH of 6.5; and a 20 mM sodium citrate buffer for a pH of 5.5. Four preservative- and antioxidant-free formulations of these APIs were developed, each aliquoted into multiple 1 mL vials for storage and sampling, as follows:

-18Tabîe3

Formulation ID	pH	Buffer	API Concentration
Fl	7.4	Na phosphate	5mMKE 5mMPE
F2	6.5	Na citrate	5mMKE 5mMPE
F3	5.5	Na citrate	5mMKE 5mMPE
F4	4.5	Na citrate	ImMKE 1 mMPE

Additional formulations were then prepared by adding either no preservatives or antioxidants (the control group), or by adding the preservative sodium ethylenediamine tetraacetic acid (also referred to as edetate disodium or EDTA) or EDTA plus the antioxidant sodium metabisulfite, as follows:

Table 4

Study Group	Study Conditions
Group 1 (Gl)	Fl	F2	F3	F4
Group 2 (G2)	Fl +0.05% w/v EDTA	F2 +0.05% w/v EDTA	F3 +0.05% w/v EDTA	F4 +0.05% w/v EDTA
Group 3 (G3)	Fl +0.05% w/v EDTA+ 0.05% w/v Na metabisulfite	F2 + 0.05% w/v EDTA+ 0.05% w/v Na metabisulfite	F3 +0.05% w/v EDTA+ 0.05% w/v Na metabisulfite	F4 +0.05% w/v EDTA+ 0.05% w/v Na metabisulfite

Samples of the various formulations in each of these groups were then stored under light shielded conditions at controlled températures of either 2-8 °C, 25 °C, 40 °C or 60 °C. Samples of each formulation were pulled at various time points over a 15 period of 12 months and analyzed for dégradation of the APIs, as determined by measuring related substances for each API. The results from this study are set forth in the tables of FIGURES 1-12, and the following conclusions were reached.

Based on stability assessments after one month of storage:

1. The control group (G 1 ) demonstrated that both APIs were stable in a Na Phosphate buffer at a pH of 7.4, and in a Na Citrate buffer at a pH of 6.5 and a pH of5.5. The control group exhibited show some dégradation at 60°C, with pH 4.5 (Na Citrate) showing the most

2. The G2 group compared to the G1 group demonstrates that EDTA inhîbits the dégradation of PE at higher températures.

3. The G3 group surprisingly demonstrates that Na metabisulfïte significantly increases the dégradation of APIs, especially KE, at elevated températures. Additionally, at one month, some G3 samples stored at 40°C and 60°C tumed yellowish.

Based on stability assessments after six months of storage:

4. EDTA surprisingly does not appear to hâve a significant effect on the stability of either API, especially in citrate buffer at a pH of 6.5.

5. The largest increase in the percent ofrelated substances at 6 months occurs in the samples held at 60 °C

6. Both APIs appear stable at 4 °C and 25 °C, with a small increase in percent of related substances at 40 °C, especially in citrate buffer at a pH of6.5.

7. At 6 months, samples at 40 °C and 60 ^PC appear bright yellow but without visible précipitation or crystallization.

Example 2

Effect of Nitrogen Overlay on Stability.

A study was then run to détermine the effect of a nitrogen overlay (i.e., the displacement of air from the head space in the vial with nitrogen before sealing the vial). The formula F2 from Example I (5 mM ketorolac, 5 mM phenylephrine in a sodium citrate buffer adjusted to pH 6.5 in an aqueous solution) was evaluated, either without any added preservative or antioxidant (group 1, Gl) or with added 0.05% w/v EDTA as a preservative (group 2, G2). Related substances for each API were measured at time points over a one year period after storing samples at températures ranging from 4 °C to 60 °C.

The results of this study are shown in FIGURES 13 and 14, and demonstrate that the use of a nitrogen overlay, as compared to the presence of oxygen containing air, significantly decreased the dégradation of both APIs, especially at elevated températures of40 °C and 60 °C. When a nitrogen overlay was used, the presence or absence of EDTA made little différence on the stability of the APIs.

Exemple 3

Effect of Different Antioxidants on Stability.

A study was then carried out to evaiuate the effect of adding altemate antioxidant agents to the formula F2 from Example 1 (5 mM ketorolac, 5 mM phenylephrine in a sodium citrate buffer adjusted to pH 6.5 in an aqueous solution) that also included 0.05% w/v EDTA as a preservative (group 2, G2). The antioxidants evaluated were 0.1% ascorbic acid (Al), 0.1% L-cysteine HCL monohydrate (A2), 0.1% L-glutathione, reduced (A3) and 0.1% monothioglycerate (A4). Related substances for each API were measured at time points over a one month period after storing samples at températures ranging from 2-8 °C to 60 °C.

The results of this study are shown in FIGURES 15-18, and demonstrate that, at the one month time ροϊηζ these four antioxidants each surprisingly increased the dégradation of each API, especially at elevated températures of 40 °C and 60 °C.

Example 4

Evaluation of Stability of Higher Concentrations of Phenylephrine

To evaiuate whether the concentration of phenylephrine in the phenylephrine HCl and ketorolac tromethamine combination formulations could be increased without deleterious effect on stability of the phenylephrine, an aqueous formulation of 450 mM phenylephrine in a calcium citrate buffer adjusted to a pH of 6.5, and no added preservatives, antioxidants or other excipients, was prepared and evaluated when samples were stored at températures between 4 °C and 40 °C over a period of 4 months.

The results of this study are provided in Figure 19. This high concentration phenylephrine formulation was stable between 4 °C and 30 °C for 4 months.

Example 5

Evaluation of Extended Stability of Phenylephrine and Ketorolac Combination

An extended stability study was performed for a formulation of a fixed combination of phenylephrine HCl (12.37 mg/mL) and ketorolac tromethamine (4.24 mg/mL) in a 20 mM sodium citrate buffer adjusted to pH 6.5, without the addition of any preservatives or antioxidants. Samples of the formulation where aliquoted into 5 mL USP Type 1 glass vials, closed with Daiko D777-1 Flurotec® coated 20 mm stoppera, and stored inverted and foil wrapped for light shielding, and then were held under long term (5 ± 3°C) and accelerated storage conditions (25 ± 2°C / 60 ± 5% RH). Each vial contained 4.5 mL of solution, including a 0.5 mL overfill.

There was no measurable change in product appearance, pH of solution, or patency when measured after 30 months of storage under these conditions. At this

month time point, storage at 5°C and 25°C resulted in a total of 1.17% and 136% related substances, respectively. A graphie display of measured potency of phenyïephrine HCI and ketorolac tromethamine for this formulation hetd under labeled storage conditions of 2°C to 8°C is provided in FIGURE 20A and FIGURE 20B, respectively. As evidenced in these figures, there was no significant décliné in. :. potency observed through 30 months (three vials were assayed at each time point).

Examples 6-9

The following Examples 6-9 provide the results of in vivo studies of phenyïephrine HCl and ketorolac tromethamine combination formulations in accordance with the présent invention, which hâve been diluted by injections into an irrigation solution that was then used for intraocular irrigation during lens replacement and exchange surgery. The following formulations were evaluated in this sériés of studies: (a) phenyïephrine HCL alone (PE), (b) ketorolac trometahamine alone (KE), (c) a combination of phenyïephrine HCL and ketorolac trometahamine (PE-KE) or (d) no active pharmaceutical ingrédients (vehicle control), in each case formulated in an aqueous solution including a 20 mM sodium citrate buffer adjusted to pH 6.5, without the addition of any preservatives or antîoxidants, in each case provided in 2.5 mL aliquots. In each case an aliquot of the formulation was injected into a balanced sait solution (BSS, Baxter Healthcare, produce code 1A7233) as the irrigation vehicle carrier to a particular final dosing concentration as described below. The studies also utilized Proparacaine HCl (0.5%, Bausch & Lomb), Tropicamide (1.0%, Bausch & Lomb) and Ciprofloxacin HCl (3%, Alcon) to the extent described below.

The mydriatic and anti-inflammatory properties of the test agents were evaluated in an African green monkey model of human phacoémulsification surgery. Prior to surgery, baseline measures and assessments were performed on both eyes in each monkey to détermine pupil diameter, lens and iris integrity, comeal thickness, and anterior chamber flare and cell count by qualitative scoring under biomicroscopy and quantitative flare photometry using a Kowa FM-500 instrument. A phacoémulsification surgery with lens replacement with a polymethyl méthacrylate (PMMA) artificial lens was performed using a Storz Premier anterior phacoémulsification machine. The procedure was only performed on the right eye to minimize surgery position variability, allow the left to serve as control, and to minimize the conséquence of any possible vision loss induced.

Test animais were placed in a prone position under ketamine/xylazine anesthesïa augmented with one drop of topical proparacaine. A small incision was

-22made in the comea of the right eye with a MVR 20 G lance blade, through which 0.40.6 mL of viscoelastic (2% hydroxypropyl methylcellulose, EyeCoat, Eyekon Medical) was introduced into the anterior chamber via a viscoelastic injector. A comeal incision was made 1.0 mm anterior to the limbus using a 2.65 mm straight 5 clear comea bi-beveled blade. Irrigation was applied with the phacoémulsification hand piece to remove viscoelastic and introduce the test perfusate. After irrigation for a total of four minutes, irrigation was stopped and the anterior chamber refilled with viscoelastic. A capsulorhexis was performed and the phacoémulsification tip reintroduced into the anterior chamber with the application of phacoémulsification 10 energy to disrupt the lens and allow aspiration and lens fragment removal. Irrigation was extended for a period after lens removal to standardize intraocular perfusate delivery across ail treatment groups (a total of 14 minutes during this phacoémulsification segment of the irrigation). Following the phacoémulsification and irrigation procedure, a PMMA intraocular lens (IOL) was inserted and an 15 additional two minutes of irrigation perfûmed, after which the comeal incision was closed with two 12.0 nylon sutures. Irrigation with a test fluid or vehicle control, as described below, was performed for a total of 20 minutes at a flow rate of 20 mL/min, prior to, during and after phacoémulsification and lens replacement.

In these studies, laser flare photometry was performed at baseline, 4.5,24,48 20 hours and 1 week after the initiation of the surgicat procedure using a Kowa FM-500 (Kowa Company, Tokyo Japan). The Kowa FM-500 measures laser light scattering to quantify anterior chamber flare. A laser is directed into the anterior chamber and protein molécules, released into the anterior chamber during an infiammatory response, pass through the focal point scattering laser light This light scattering is 25 quantifîed by a photomultiplier tube as photon counts per millisecond. At each observation point measurements were collected until scven acceptable readings (différence between two background measurements < 15%) were obtained and the lowest and highest readings were deleted and the mean value +/- the standard déviation calculated, as specified by the manufacturer.

The time course of the mydriatic effect was documented through video recording of the pupil during the perfusion procedure. Pupil diameter and the fixed width of the lid spéculum (11 mm) were measured from the screen image to allow calculation of the pupil diameter in millimeters. Measurements were made at periodic intervals during the course of the infusion procedure according to the video 35 time log for each documented procedure.

The primary efficacy variables were the pupil diameter and the laser flare photometer measures. Primary efficacy variables were analyzed in the protocol correct population (ail subjects who completed the study without a major protocol déviation) using a one-way, repeated measure ANOVA method with post hoc Student Newman-Keuls tests employing SAS (SAS Institute Inc.). Terms of the ANOVA analysis included sequence (= time, confounded with canyover effect), eye, monkey and treatment Appropriate model-based comparisons were employed to detect treatment différence at the significance Ievel of p < 0.05 for pupil diameter and flare measures at ail time points.

Example 6

Concentration-Ranging Study of Phenylephrine and Ketorolac Following Intraoperative Irrigation in a Phacoémulsification Surgical Model

A non-GLP study was conducted as a concentration-ranging efficacy study to evaluate PE and KE when given individually and combined via intraocular irrigation in BSS during cataract surgery. The objectives were to evaluate the benefit of each agent on both mydriatic and inflammatory endpoints.

In a first sériés of experiments, designated Phase 1, 16 animais were divided into groups of four and studied to establish the maximally effective concentration of phenylephrine in a BSS irrigation solution in this model of phacoémulsification surgery. Four of the monkeys in the Phase 1 cohort received tropicamide, a muscarmic mydriatic, to serve as a positive control and allow détermination of the endpoint measures of interest under adéquate pupil dilation by the standard topical preoperative route of delivery. The phenylephrine treatment groups received a low (3 uM), intermediate (10 uM), high (30 uM) and highest (90 uM) concentration of phenylephrine-containing BSS perfusate. The low and highest treatment groups consisted of 2 animais each as the decision was made to evaluate a higher concentration of phenylephrine as the phase 1 portion was underway. The primary endpoint for phenylephrine efficacy was mydriasis. Inflammatory endpoints following the surgery were also evaluated.

BSS perfusate was delivered through the phacoémulsification needle either without phenylephrine or containing phenylephrine at a concentration of 3.0 μΜ, 10 μΜ, 30 μΜ or 90 μΜ (see Table 1). Stage 1 irrigation (0:00 - 2:00 minutes) was applied to remove the viscoelastic and assess the mydriatic effect of phenylephrine and continued through Stage 2 irrigation (2:00 - 4:00 minutes), after which viscoelastic was reintroduced into the anterior chamber and a capsulorhexis was performed. Stage 3 irrigation (4:00 - 18:00 minutes) was begun after the

capsulorhexis and continued for a total of 14 minutes, during the early stage of which the lens was fragmented and aspîrated by application of phacoémulsification energy. Stage 4 irrigation took place after the introduction of the PMMA lens to evacuate viscoelastic material introduced for that procedure and to remove any additional lens 5 fragments. The tropicamide controi animais were pre-treated with two drops of 1% tropicamide 20 minutes prior to the initiation of anterior chamber irrigation with BSS alone.

Following the first few animal surgeries, the duration of the initial prephacoemulsifîcation irrigation was extended from 2 to 4 minutes to capture maximal 10 pupil dilation.

The second sériés of experiments, designated Phase 2, evaluated mydriasîs and inflammation following phacoémulsification surgery in which a BSS perfusate containing low, mid and high concentration of ketorolac, or no ketorolac (négative controi) was employed. Anterior chamber perfusions were initiated using no 15 mydriatic agent in the irrigation solution to assess the mydriatic effect of ketorolac and BSS alone. After 2 minutes of irrigation and assessment of mydriasîs, a concentration of phenylephrine (30 uM), found to be effective in achieving mydriasîs in Phase 1 experiments, was included in the perfusate solution to provide sufficient dilation for the phacoémulsification procedure to be performed. The secondary 20 endpoint for ketorolac efficacy was mydriasîs, and the primary endpoint was laser flare photometry, a validated measure of anterior chamber inflammation.

BSS perfusate was delivered through the phacoémulsification needle either without ketorolac or containing ketorolac at a concentration of 3.0 μΜ, 10 μΜ, or 30 μΜ (see Table 1). Stage 1 irrigation (0:00 - 2:00 minutes) was applied to remove the 25 viscoelastic and assess the mydriatic effect of ketorolac. High concentration phenylephrine was then added to the perfusate bottle (to achieve a concentration of 30 μΜ), the fines were flushed and irrigation was continued through stage 2 (2:00 4:00 minutes), after which viscoelastic was reintroduced into the anterior chamber and a capsulorhexis was performed. Stage 3 irrigation (4:00 - 18:00 minutes) was 30 begun after the capsulorhexis and continued for a total of 14 minutes, during the early stage of which phacoémulsification energy was applied. Stage 4 irrigation took place after the introduction of the PMMA lens.

Results

After an initial pupil dilation of 1-2 mm within the first minute of the start of 35 anterior chamber perfusion, the pupil diameter asymptotically approached maximal dilation within approximately five minutes for ail treatment groups (see FIGURES 21

and 22) with a significant effect of time on diameter (F ~ 2.75, P < 0.0001). In the first set of experiments, trends suggest that the presence of phenylephrine in the BSS perfusate contributed to a concentration-dependent increase in pupil diameter. The initial dilation (0-2 min) exhibited in the control group, which received topical 5 tropicamide 20 minutes prior to irrigation with BSS alone, was likely not a pharmacologie effect and reflects a component of the dilation measured within the first 2 minutes of the onset of anterior chamber irrigation in ail groups was related to clearance of the viscoelastic introduced to allow création of the comeal incision and a possible hydrodynamic effect of irrigation/aspiration. Of note, however, the early 10 additional dilation in the tropicamide control group started from a baseline dilation greater than ail other treatment groups (F = 7.73, P < 0.0001) at the begînning of the procedure and resulted in a lower maximal dilation than exhibited by the mid, high and highest concentration phenylephrine groups. Différences between the highest, high and mid phenylephrine groups and the low phenylephrine group were 15 significant at the 6:00, 8:00, 10:00, 14:00, 18:00 and 19:00 minute time points (F =

2.41, p < 0.043; F = 2.66, p < 0.0315; F = 324, p < 0.0136; F = 6.62, p < 0.0002; F = 9.26, p < 0.0001; F = 3.79, p < 0.005; respectively, Student Newman-Keuls test, a 0.05, df = 23, see FIGURE 21), confîrming a concentration -dépendent effect of phenylephrine perfusate on the amplitude of intraoperative mydriasis. Différences 20 between the highest, high and mid- concentration phenylephrine groups versus the low concentration phenylephrine and tropicamide control group were significant at the 14:00 and 18:00 minute time points (F = 6.62, p < 0.0002; F = 926, p < 0.0001; respectively, Student Newman-Keuls test, a = 0.05, df = 23, see FIGURE 21), indicating the concentration-dependent effect of phenylephrine in prolonging 25 intraoperative mydriasis. Différences between ali other groups at ail other time points were not significant by the Student Newman-Keuls criteria, but trends observed in the mean pupil diameter within groups would suggest a concentration dependence to both rate of onset and amplitude of mydriatic effect across phenylephrine groups. At later time points mean dilation in the high phenylephrine 30 treatment group approaches the anatomie limit of pupil mydriasis of 8.3 mm in the adult eye in this species (corresponding to the inner diameter of the comeal limbus).

In the second set of experiments, in which the anterior chamber was irrigated with BSS containing 3-30 μΜ ketorolac or BSS alone for 2 minutes prior to the introduction of 30 μΜ phenylephrine, there was a rapid 1-2 mm increase in pupil 35 diameter within 30 seconds of the start of perfusion followed by a Iess rapid concentration -independent rise between 30 seconds and two minutes. No statistical

-26différences were seen between the ketorolac-treated groups and the BSS-treated animais during the initial two minutes. Given that the same behavior was demonstrated by the BSS control group it is likely that this initial dilation is related to viscoelastic clearance and the hydrodynamic effects of irrigation/aspiration, as 5 evidenced by the behavior of the phenylephrine and tropicamide control groups in the first set of experiments. After introduction of 30 μΜ phenylephrine in ail ketorolac- and BSS-treated animais at two minutes there was a further rapid increase in pupil diameter in ail groups reaching maximum dilation at four minutes. Maximal dilation was sustained through the remaining perfusion period after a s light decrease 10 in pupil diameter in the interval between the four minute initial perfusion and the start of phacoémulsification when the capsulorhexis was performed. There were no statistically significant group différences, except between the low and mid concentration ketorolac groups versus the BSS and high concentration ketorolac groups at the 14:00 and 18:00 minute time points (Low and Mid > BSS and High; F 15 = 6.62, p < 0.0002; F = 9.26, p < 0.0001; respectively; Student Newman-Keuls test, a = 0.05, df = 23, see Figure 2). The treatment grouping of this différence, however, would suggest that the différence did not resuit from a ketorolac effect, and was likely related to the limited sample size, and reflective of inter-animal and interprocedure différences. In ail treatment groups in both sets of experiments studies the 20 pupil constricted following lens placement at the end of the procedure.

Baseline preoperative anterior chamber flare measures ranged from 3.0 to 12.7 photon units/ms (mean = 6.0 +/- 2.4 SD) in ail treatment groups in the treated (right) eye. Flare measures in the control (teft) eye remained within this range throughout the duration ofthe study. These measures matched anterior chamber flare 25 assessments performed by slit lamp biomicroscopy, validating the utility of the laser flare photometer in quantifying the protein density in the anterior chamber in the eye’s quiescent naturel state. In ali treatment groups there was a significant effect of time on flare measurements in the treated eye (F = 2.16, p < 0.0034), further confîrming the utility of flare photometry in quantifying intervention related 30 inflammation (see Figures 23,24 and 25). Flare measures in treated eyes at baseline versus 4.5 and 24 hours versus 48 and 168 hours were sîgnificantly different across ail treatment groups (F = 2.16, p < 0.0034; Student Newman-Keuls test, a = 0.05, df = 75). Différences between the control and treated eye were different at ail postoperative exam time points across ail subjects (F = 236.64, P < 0.0001; Student 35 Newman-Keuls test, a ~ 0.05, df = 195).

of

-27In the first set of experiments, phacoémulsification duration differed within treatment groups as idéal parameters were being refined. It was established in the first 4 surgi cal procedures that the phacoémulsification time was causing a severe inflammatory response and réduction in phacoémulsification was agreed to. Analysis of longer duration phacoémulsification (45-55 secs) versus shorter duration (15-25 secs) groups at the 4.5 hour and 24 hour time points revealed a statisticalty significant increase in flare measures with phacoémulsification duration (F = 4.42, p< 0.0018; Student Newman-Keuls test, a = 0.05, df = 14; see Figure 24), confirming the utility of laser flare photometry in quantifying the extent of anterior chamber injury and inflammation. This différence resolved by the 48 and 1 week time points.

Analysis with the exclusion of the high phacoémulsification energy subjects, which included 2 monkeys in each of the high phenylephrine and tropicamide groups, revealed no treatment effect on flare measures of phenylephrine relative to the tropicamide control at ail time points (Student Newman-Keuls test, a = 0.05, df=

7)·

In the second set of experiments, despite the small group sizes, there was a consistent trend for a réduction in the flare measurements in the mid and high ketorolac groups. There was a statistically significant différence between flare measures in the BSS control group versus the mid and high concentration ketorolac groups which achieved signifîcance at the 4.5 hour time point when these two treatment groups were combined to add power to the analysis (F = 5.17, P < 0.0223; Student Newman-Keuls test, a = 0.05, df = 13; see Figure 25). Flare measurements in the high and mid dose ketorolac group remained lower relative to the control group at the 24 and 48 hour time points, but these différences did not achieve statistical signifîcance, whether the high and mid dose ketorolac groups were analyzed in combination or separately, given the power of the analysis. At one week there were not statistically significant différence between any of the treatment groups but the high concentration ketorolac group maintained a similar trend.

Conclusions

The African green monkey phacoémulsification model allowed the quantification of mydriatic and inflammatory measures relevant to human clinical endpoints. Of these measures, video pupil diameter assessments and anterior chamber flare photometry were the most responsive to treatment effects at the time points assessed. Video pupil data demonstrated that intraoperative delivery of phenylephrine in the anterior chamber perfusate resulted in a rapid onset mydriasis which was maintained throughout the surgical procedure. The maximal mydriasis

attained was concentration-dependent, with adéquate mydriasis for a phacoémulsification surgical procedure to be performed at ali concentrations evaluated. Concentrations equal to or greater than 10 μΜ resulted in a mydriasis exceeding that obtained by preoperative topical 1% tropicamidc, a standard of care 5 for cataract procedures. Flare photometry and pachymetry measures did not indicate a réduction in anterior chamber inflammation or comeal edema associated with the addition of phenylephrine to the anterior chamber perfusate.

Video pupil data demonstrated that intraoperative delivery of ketorolac in the anterior chamber perfusate did not resuit in a change in mydriasis substantially 10 different from that observed with BSS alone. Once phenylephrine at a concentration of 30 μΜ was added to the perfusate, however, rapid dilation occurred, confïiming the previously demonstrated utility of the intraoperative delivery of phenylephrine. Flare photometry measures indicated a positive effect of ketorolac on anterior chamber inflammation immediately postoperatively at 4.5 hours.

Example 7 Study of Phenylephrine and Ketorolac Combination ln Phacoémulsification Surgical Model

A non-GLP study was conducted with an irrigation solution containing 20 90 μΜ PE . and 30 μΜ KE to evaluate the effect of the combination when administered via intraocular irrigation during cataract surgery on mydriasis and inflammatory endpoints. In this sériés of experiments, 14 monkeys were divided into groups of seven and studied to establish the efficacy of BSS alone versus a BSS perfusate containing the PE and KE combination. Efficacy endpoints included 25 mydriasis and laser flare photometry as a measure of anterior chamber inflammation.

The control group additionally received the muscarinic mydriatic tropicamide preoperatively to allow sufïïcient dilatation to employ the African green monkey model of phacoémulsification surgery.

Results

Animais irrigated with the PE-KE combination achieved 6.0-6.5 mm pupil dilation within approximately 60 sec of irrigation (see FIGURE 26). These values were équivalent to those obtained after preoperative treatment with tropicamide. After an initial pupil dilation of 3.0-4.0 mm within the first minute of the start of anterior chamber perfusion, the pupil diameter plateaued within approximately 2.5 and 3.5 minutes for both the tropicamide control and the PE-KE treatment groups, respectively (see Figure 1), with a significant effect of time on pupil diameter (F =

86.69, P < 0.0001; Student Newman-Keuls test, a = 0.05, df - 12). The initial dilation (0-2 min) exhîbited in the control group, which received topical tropicamide 20 minutes prior to irrigation with BSS alone, was likely not a pharmacologie effect and reflects hydrodynamic effects of imgation/aspiration and/or dilation associated with clearance of the viscoelastic introduced to allow création of the comeal incision. Of note, however, the early additional dilation in the tropicamide control group started from a baseline dilation greater than the treatment group (F = 86.69, P < 0.0001; see FIGURE 26) at the beginning of the procedure and resulted in a lower maximal dilation than exhibited by the PE-KE treatment group. PE-KE-mediated pupil dilation exceeded the dilation achieved by the preoperative administration of tropicamide within 90 seconde of the initiation of anterior chamber irrigation. Différences between the control group and the treatment group receiving PE-KE were significant at the 0:00, 3:30, 4:00, 4:30, 5:00, 5:30, 6:00, 8:00, 10:00, 12:00, 12:30 and 13:00 minute time points (F = 25.08, p < 0.003; F = 5.61, p < 0.0355; F = 9.95, p < 0.0083; F = 14.71, p < 0.0024; F - 18.01, p < 0.0011; F = 9.93, p < 0.0084; F = 10.39, p < 0.0073; F = 14.77, p < 0.0023; F = 14.77, p < 0.0023; F = 28.65, p < 0.0002; F = 20.51, p < 0.0007; F = 8.66, p < 0.0134; F = 5.48, p < 0.0391, respectively; Student Newman-Keuls test, a = 0.05, df = 12; see FIGURE 26).

The observed group différences confîrmed a treatment effect of the PE-KE perfusate containing phenylephrine and ketorolac on the amplitude of intraoperative mydriasis and on the prolongation of intraoperative mydriasis. Différences between the two groups at early time points were not significant by the Student NewmanKeuls criteria, reflecting intra-group variability, but trends observed in the mean pupil diameter suggest a treatment effect to both rate of onset and amplitude of mydriatic effect. At later time points mean dilation in some subjects in the PE-KE treatment group approached the anatomie limit of pupil mydriasis of ~10.5 mm in the adult eye in this species (corresponding to the inner diameter of the comeal limbus).

Baseline preoperative anterior chamber flare measures ranged from 1.6 to 9.9 photon units/ms (mean = 53 +/- 23) in both treatment groups in the operative (right) eye. In both treatment groups there was a significant effect of time on flare measurements in the treated eye, further confînning the utility of flare photometry in quantifying intervention related inflammation (see FIGURE 27). Flare measures in treated eyes at baseline versus 2, 4.5, 24, 48 hours and 1 week were significantly different across both treatment groups (F = 4.94, p < 0.0008; Student Newman-Keuls test, a = 0.05, df - 59).

The PE-KE treatment group had lower values of flare measures over time relative to the tropicamide control group, but they did not achieve statistical significance at any time point (F = 3.32, P < 0.0935; Student Newman-Keuls test, a = 0.05, df = 12; see FIGURE 27), in part reflecting a large variabilîty in subject 5 response to the experimental intervention. One PE-KE treated subject exhibited a more limited pupil dilation during anterior chamber irrigation, complicating lens removal. Analysis of flare measures with the exclusion of this animal reveal a statistically significant différence between the PE-KE treatment group and the tropicamide control group at the 2-, 4.5-, 24- and 48-hour time points (F = 9.74, P < 10 0,0097; Student Newman-Keuls test, a = 0.05, df - 11; see FIGURE 28). At one week there was not a statistically significant différence between the treatment groups.

Conclusions

The African green monkey phacoémulsification model allowed the quantification of mydriatic and inflammatory measures relevant to human clinical endpoints. Of these measures, video pupil diameter assessments and anterior chamber flare photometry were the most responsive to treatment effects at the time points assessed. Video pupil data demonstrated that intraoperative deliveiy of PEKE in the anterior chamber perfusate resulted in a rapid onset of mydriasis, which was maîntained throughout the surgical procedure. The mydriasis attained was adéquate for a phacoémulsification surgical procedure to be performed within the initial 60 seconds of irrigation. The degree of mydriasis exceeded that obtained by preoperative topical 1% tropicamide, a standard of care for cataract procedures. Flare photometry measures suggest a positive effect of PE-KE on anterior chamber inflammation immediately postoperatively.

Example 8

Dose Response Study of Phenylephrine and Ketorolac Combination In Phacoémulsification Surgical Model

This non-GLP study was conducted to establish the dose response and time course of mydriasis following intracameral delivery of low-, mid-, and highconcentration irrigation solutions containing PE and KE to African green monkeys. The PE-KE formulation contained a fixed ratio of 3:1 of 45 mM phenylephrine and 15 mM ketorolac in a 20 mM sodium citrate buffer (pH 6.5). An additional concentrated 450 mM phenylephrine HCl (PE) formulation was provided to elevate the phenylephrine concentration in the high dose group. The time course of mydriasis was evaluated by video in four monkeys following intracameral administration of the low concentration of PE and KE (90:30 μΜ) irrigation solution, in four monkeys following the mid concentration (268:89 μΜ) and four monkeys following the high concentration (1165:89 μΜ). The volumes of ail intracameral administrations were 150 pL with éjection of the syringe volume into the anterior chamber occurring over approximately a fîve-second period.

To mix the low concentration (PE:KE at 90:30 μΜ), 1.0 mL from one vial of PE-KE drug composition was withdrawn and injected into a 500-mL BSS irrigation bottle. For the mid concentration (PE:KE at 268:89 μΜ), three vials of PE-KE drug composition were used with 1.0 mL from each vial withdrawn and injected into a 500-mL BSS irrigation bottle. For the high concentration group (PE:KE at 1165:89 μΜ), additional phenylephrine HCl was added to the PE:KE in BSS solution.

Results

Monkeys injected with intracameral PE/KE irrigation solution achieved approximately 6-7 mm pupil dilation within 60 seconds of irrigation. As shown in FIGURE 29, after an initial rapid pupil dilation, the pupil diameter plateaued at approximately the 1-minute time point, with a significant effect of time on pupil diameter among ail treatment groups (F = 64.33, p < 0.0001). Différences between the low-dose group (90:30 μΜ) and the high-dose group (1165:89 μΜ) were statistically significant at the 1:30-, 3:00- and 3:30-minute time points (Student Newman-Keuls test, a = 0.05, df - 9).

Conclusions

The African green monkey mydriasis model allowed the quantification of pupil responses that are relevant to human clinical endpoints. Video pupil data demonstrated that intracameral delivery of PE-KE into the anterior chamber resulted in a rapid onset mydriasis, which was maintained throughout the ten minute period during which video documentation occurred. The mydriasis attained was adéquate for a phacoémulsification surgical procedure to be performed within the initial 60 seconds following administration. The degree of mydriasis was greater than that obtained in the control arm of previous efficacy studies by the preoperative delivery of topical 1% tropicamide (mean pupil diameter of 5.9 mm), a standard of care for cataract procedures.

Example 9 Safety Study of Phenylephrine and Ketorolac Combination in Phacoémulsification Surgical Model

A nonclimcal GLP toxicology study was carried out in African green monkeys. Twelve male and twelve female monkeys underwent phacoémulsification surgcry with lens replacement and two-week recovery in this study. Continuons irrigation of PE-KE irrigation solution throughout the anterior chamber and associated ocular structures was conducted during the surgery and represents the intended route of administration of this product. Three concentrations were evaluated: 720 μΜ PE and 90 μΜ KE (720:90 μΜ) in the low concentration group, 2160 μΜ PE and 270 μΜ KE (2160:270 μΜ) in the mid concentration group, and 7200 μΜ PE and 900 μΜ KE (7200:900 μΜ) in the high concentration group.

A separate control group was evaluated as well. An equai number of male and female animais were allocated to each group with assignaient based on weight rank to achieve a balanced mean weight. AU animais underwent a surgical procedure on Day 0 to replace the întraocular lens.

Results

Ail animais tolerated the surgical procedures well, had uneventful recoveries, and survived to the scheduled sacrifice and necropsy. No treatment-related effects were observed on respiratory and cardiovascular observations and ail clînical laboratory parameters.

The initial intracameral delivery of 150 pL of each PEZKE irrigation solution resulted in rapid pupîl dilation within 30 seconds, with dilation increasing to 6.76 ± 0.15 to 7.29 ±0.15 mm (mean ± SD) in a dose-dependent manner. Thirty seconds following intracameral delivery of 150 μΐ of BSS alone, the pupil diameter of the tropicamide control group was 5.18 ± 0.18 mm.

The low-concentration treatment group had Iower values of flare measures relative to the tropicamide control group at 4.5 hours and 14 days, but they did not achieve statistical signifîcance at any time point, while flare response in the hîghconcentration treatment group was nearly identical to that of the control group at ail time points. The mid-concentration treatment group had higher flare measures relative to the tropicamide control, low-concentration and high-concentration at ail post-surgical time points, achieving signifîcance at 2, 4.5, and 24 hours. These fîndings are believed secondary to greater surgical trauma in the mid-concentration treatment group. No concentration-dependent effects on flare were seen. At two weeks, there was not a statistically sîgnifîcant différence between the treatment 20 groups.

In the control, low-concentration, and high-concentration treatment groups, there was a decrease in intraocular pressure following phacoémulsification surgery, but différences from baseline did not achieve signifîcance. At the 4.5-hour time point, the intraocular pressure in the mid-concentration treatment group was 25 significantiy greater than in the other treatment groups, but not different than baseline. There was an overall trend of decreasing postoperative intraocular pressure.

Baseline clînical évaluations of the pupil, comea, lens, and iris were within normal limita in the operative (right) and nonoperative (left) eye of ail animais. The pupil diameter retumed to baseline by the 24-hour time points, indicating minimal 30 residual treatment-associated mydriatic or miotic effect

Example 10

Clinlcal Study

A Phase 2b human clînical study evaluated a ketorolac and phenylephrine combination drug composition, fonnulated in accordance with Formula 1 of the 35 présent invention-, for its effect on the maintenance of intra-operative mydriasis (pupil dilation) and réduction of postoperative pain and irritation resulting from

-34cataract and other lens replacement surgeiy. The combination drug composition was diluted into a balanced sait solution irrigation carrier prior to intraocular administration during intraocular surgical procedures.

The subject Phase 2b study was a randomized, parallel group, vehîclecontrolled, factorial design study, and was run to compare phenylephrine (PE), ketorolac (KE) and the combination drug composition containing both PE and KE in subjects undergoing unilatéral cataract extraction with lens replacement (CELR) using a coaxial phacoémulsification process with insertion of an acrylic lens. Administration of test irrigation solutions occurred in a double-masked fashion. The study evaluated, in a four-arm full-factorial design, the contribution of the two active pharmaceutical ingrédients (PE and KE, alone and in combination) to the maintenance of mydriasis and post-operative réduction in pain when administered diluted in balanced sait solution (BSS). The study also explored the effect of the combination drug composition, PE, and KE on postoperative inflammation. Subjects were randomized to one ofthe following four treatment arms in a 1:1:1:1 fashion:

a. BSS vehide

b. 483 μΜ PE in BSS

c. 89pMKEinBSS

d. the combination drug composition containing 483 μΜ PE and 89gMKEinBSS.

Ail subjects in this study received preoperative mydriatics and anesthetics. In each of the four groups, the respective irrigation treatment was administered as a single irrigation of the anterior chamber of the eye during the CELR surgical procedure, with a mean of 8 minutes of exposure in this study. In addition, at the end of the procedure, the anterior chamber was filled with the irrigation treatment. The change in pupil diameter over time from surgical baseline (immediately prior to surgical incision) to the end of the surgical procedure (wound closure) was measured, as was postoperative pain on the day of operation as measured by the Visual Analog Scale (VAS) at 2,4 6, 8 and 10-12 hours and at other times recorded by the patient prior to taking rescue pain médication.

In this 223-patient Phase 2b clinical study, subjects treated with the combination drug composition demonstrated statistically significant (p<0.0001) and clinically meaningful maintenance of mydriasis throughout the cataract procedure as compared to either the BSS or KE groups. Maintenance of mydriasis is critical to performing lens exchange safely and proficiently given that the ophthalmologist opérâtes through the pupil. If mydriasis is not maintained throughout the procedure,

-35the risk of injuring structures within the eye increases and the required operating time is often prolonged. Any réduction in pupil size during surgery may interfère with surgical technique. In this study the mean pupil diameter was 8.3 mm at the time of the incision. A réduction of 2.5 mm or more (‘extreme constriction”) represents a loss of 30% of the diameter and 52% of the area ofthe average pupil, with a potential for extreme impact on the procedure. Unexpectedly, this study demonstrated that 21% of subjects in the BSS group and 21% of subjects in the KE group experienced this extreme constriction, as compared to only 4% of subjects in the combination drug composition group.

Intraoperative complications increase when the pupil diameter is less than 6 mm during lens exchange surgery. A categorical analysis on an intent-to-treat basis of intraoperative pupil diameters to identify the proportions of study subjects who experienced this level of pupil constriction. In this Study, the combination drug composition was statistically significantly superior (Table XX) in preventing this degree of pupil constriction, i.e., miosis to a diameter of less than 6 mm, when compared to each of the other three treatment arms.

Table5

Subjects Having Punil Diameter < 6mm during CELR

BSS >54)	KE/PE Combination (n=49)	KE >52)	PE (n=49)
25 (46%)	3 (6%)	18(35%)	11(22%)
p<0.0001*		p=0.0005*	p=0.0404*

*FET comparison to PE-KE combination

Clmically signifïcant réductions in pupil diameter are associated with an increase in procedure-related complications, including posterior capsule tears, retained lens fragments and vitreous leaks. These fîndings demonstrate that the phenylephrine and'ketorolac each contribute and act synergistically in preventing clinically meaningfiil mioisis.

This fînding is surprising because phenylephrine is a strong mydriatic agent and would be expected to inhibit miosis alone. Surprisingly, ketorolac also provided an anti-miotic effect on top of the effect of phenylephrine.

Additionally, the combination drug composition also significantly decreased pain in the early postoperative period (10-12 hours post-surgery) relative to either the

PE (p=0.0089) or BSS (p=0.0418) groups. Surprisingly, the combination drug composition also reduced the frequency of complaints of moderate and severe pain (2.5 times more complainte in the BSS-treated subjecte). The drug composition was safe and well tolerated in this study.

This study demonstrates that the composition and use of the invention claimed in the above-identifïed application prevents a surprising degree of extreme pupil constriction, as well as resulting in an unexpected réduction of moderate and severe post-operative pain up to 10-12 hours after surgery following mere minutes of exposure to the test drug during surgery.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be readily apparent to one of ordinary skill in the art in light of the teachings of this invention that certain changes and modifications may be made thereto without departing from 15 the spirit or scope of the appended claims.

Claims (5)

The embodiments of the invention in winch an exclusive property'ürpnvilege is claimed are defined as follows:

1. A stérile liquid pharmaceutical formulation comprising phenylephrine, ketorolac and a buffer system in an aqueous carrier, wherein the formulation is preservative-free and

5 antioxidant-free and is stable for at least six months when stored at a température of from 5+/3°Cto25+/-2°C.

2. The pharmaceutical formulation of claim 1, wherein the buffer system is selected from a sodium phosphate buffer system and a sodium citrate buffer system.

3. The pharmaceutical formulation of claim 2, wherein the buffer system comprises 10 an about 20 mM sodium citrate buffer system.

4. The pharmaceutical formulation of claim 1, wherein the pharmaceutical formulation has a pH of from 5.8 to 6.8.

5. The pharmaceutical formulation of claim 1, wherein formulation is stable for a period of at least 24 months when stored at a température of from 5+/-3°C to 25+/-2°C.

15

6. The pharmaceutical formulation of claim 1, wherein the formulation is contained within a single-use container.

7. The pharmaceutical formulation of claim 1, wherein the formulation comprises from 46 to 76 mM phenylephrine and from 8.5 to 14 mM ketorolac.

8. The pharmaceutical formulation of claim 7, wherein the formulation comprises 20 about 60.75 mM phenylephrine and about 11.25 mM ketorolac.

9. The pharmaceutical formulation of claim 1, further comprising an intraocular irrigation carrier into which the formulation is injected, wherein after injection the phenylephrine is présent at a concentration of from 30 to 720 μΜ and the ketorolac is présent at a concentration of from 44 to 134 μΜ.

25

10. The pharmaceutical formulation of claim 1, further comprising an intraocular irrigation carrier into which the formulation is injected, wherein after injection the phenylephrine is présent at a concentration of from 240 to 720 μΜ and the ketorolac is présent at a concentration of from 10 to 270 μΜ.

11. lhe pharmaceutical formulation of claim 1, wherein the phenylephrine and ketorolac are included at a molar ratio of from 1:1 to 13:1 phenylephrine to ketorolac.

12. The pharmaceutical formulation of claim 1, wherein the phenylephrine and ketorolac are included at a molar ratio of from 3:1 to 10:1 phenylephrine to ketorolac.

5 13. A stérile liquid pharmaceutical dosage form for injection, comprising phenylephrine, ketorolac, a buffer system and an aqueous carrier packaged in a single-use container for injection, wherein the dosage form is preservative-free and antioxidant-free.