EXHIBIT A

Case: 1:12-cv-03846 Document #: 1-1 Filed: 05/17/12 Page 1 of 7 PageID #:7
c12) United States Patent 

Pavliv 

(54) ACETYLCYSTEINE COMPOSITION AND 

USES THEREFOR 

(75) Inventor: Leo Pavliv, Cary, NC (US) 

(73) Assignee: Cumberland Pharmaceuticals, Inc., 

Nashville, TN (US) 

( *) Notice: Subject to any disclaimer, the term of this 

patent is extended or adjusted under 35 

U.S.C. 154(b) by 270 days. 

(21) Appl. No.: 11/209,804 

(22) Filed: Aug. 24, 2005 

(65) Prior Publication Data 

US 2007/0049640 AI Mar. 1, 2007 

(51) Int. Cl. 

A61K 31133 (2006.01) 

(52) U.S. Cl. ....................................................... 514/183 

(58) Field of Classification Search . ... ... ... ... .. ... . 514/183 

See application file for complete search history. 

(56) References Cited 

U.S. PATENT DOCUMENTS 

4,849,452 A 

5,114,974 A 

5,124,351 A 

5,206,269 A 

5,272,166 A 

5,354,748 A 

5,474,757 A 

5,691,380 A 

5,700,653 A * 

5,807,894 A * 

5,882,688 A 

6,103,748 A 

6,114,387 A 

6,149,891 A 

6,281,222 B1 

6,355,682 B1 

6,468,965 B1 

7 I 1989 Dulce eta!. 

5/1992 Rubin 

6/1992 Rabinovitz eta!. 

4/1993 Ludwig eta!. 

12/1993 Breslow eta!. 

10/1994 Sugita et a!. 

12/1995 Yang 

1111997 Mason eta!. 

12/1997 Lu et al ........................... 435/15 

9/1998 Stroppolo eta!. 514/562 

3/1999 Alonso et a!. 

8/2000 Bryan 

9/2000 Cutler 

1112000 Korenstein et al. 

8/2001 Salzman eta!. 

3/2002 Weinberg 

10/2002 Cutler 

200110031737 A1 

2002/0002146 A1 

2002/0025310 A1 

2002/0031513 A1 

2004/0022873 A1 * 

10/2001 Richardson eta!. 

112002 Halevie-Goldman 

212002 Bland 

3/2002 Leibovitz 

2/2004 Guilford eta!. .............. 424/702 

CA 

CA 

EP 

FR 

GR 

FOREIGN PATENT DOCUMENTS 

821 525 A 

2 526 208 A1 

0639375 A1 * 

2 788 436 A 

1 002 731 B 

8/1969 

12/2004 

2/1995 

7/2000 

7/1997 

111111 1111111111111111111111111111111111111111111111111111111111111 

US008148356B2 

(10) Patent No.: US 8,148,356 B2 

(45) Date of Patent: Apr. 3, 2012 

JP 

wo 

wo 

7309746 

WO 01180832 A2 

WO 03/011249 A 

* 1111995 

1112001 

2/2003 

OTHER PUBLICATIONS 

Merck Index 13th ed., n. 3546, pp. 620-621 (2001). 

Merck Index 131

h ed., n.90, p. 17 (2001). 

Handbook of Pharmaceutical Excipients, 225-228, (R. Rowe et al. 

eds), 41

h ed. (2003). 

Tepel at a!., "Prevention of Radiographic-Contrast-Agent-Induced 

Reductions in Renal Function by Acetyl cysteine," The New England 

Journal of Medicine 343(3):180-184 (2000). 

Package Insert of Acetadote®, Intravenous N -Acetylcysteine, 

Cumberland Pharmaceuticals, Inc. (2004). 

Package Insert of Parvolexe® Injection, Acetylcysteine, David Bull 

Laboratories (200 1 ). 

Package Insert of Acetylcysteine Solution, USP, American Regent 

Laboratories, Inc. (1998). 

Van Loenen A.C. et al., "Bereiding en houdbaarheid van een 

acetylcysteine-injectie/Formulation and shelf-life of acetyl cysteine 

injections," Pharm Weekbl120:313-317 (1985). 

International Search Report and Written Opinion of the International 

Searching Authority for International Application No. PCT /US2006/ 

020691 (Nov. 27, 2006). 

Package Insert of Fluimucil® Injection, Acetylcysteine, Zarnbon 

GmbH (2000). 

* cited by examiner 

Primary Examiner- Brandon Fetterolf 

Assistant Examiner- Christopher R Stone 

(74) Attorney, Agent, or Firm- Stites & Harbison PLLC; 

RichardS. Myers, Jr. 

(57) ABSTRACT 

This invention relates to novel acetylcysteine compositions in 

solution, comprising acetylcysteine and which are substantially free of metal chelating agents, such as EDT A. Further, 

this invention relates to methods of making and using the 

acetylcysteine compositions. The present compositions and 

methods are designed to improve patient tolerance and compliance, while at the same time maintaining the stability of the 

pharmaceutical formulation. The compositions and methods 

of this invention are useful in the treatment of acetaminophen 

overdose, acute liver failure, various cancers, methacrylonitrile poisoning, reperfusion injury during cardia bypass surgery, andradiocontrast-induced nephropathy, and can also be 

used as a mucolytic agent. 

14 Claims, No Drawings 

Case: 1:12-cv-03846 Document #: 1-1 Filed: 05/17/12 Page 2 of 7 PageID #:8
US 8,148,356 B2 

1 

ACETYLCYSTEINE COMPOSITION AND 

USES THEREFOR 

FIELD OF THE INVENTION 

The present invention relates to acetylcysteine compositions in solution and their use. In certain embodiments of this 

invention, the acetyl cysteine composition is substantially free 

of chelating agents, which does not significantly impact the 

stability of the formulation. In other embodiments of the 

invention, the acetyl cysteine composition is substantially free 

ofEDTA. 

BACKGROUND OF THE INVENTION 

Acetylcysteine is an antioxidant having a molecular weight 

of 163.2 and the following chemical structure: 

H 

I 

CH3YN~SH 

0 COOH 

(Merck Index 13'h ed., n90, page 17). Acetyl cysteine is marketed generically in the United States and worldwide, as well 

as under the trade names of Acetadote® Mucomyst® Parvolex®, Fluimucil®, and others. It is a~proved for s~veral indications including treatment of acetaminophen overdose, 

as an injectable and an oral agent, and as a mucolytic, as an 

inhalation product. Acety !cysteine is also being used or investigated to treat other indications including liver failure, various cancers, methacrylonitrile poisoning, reduction of radiocontrast-induced nephropathy, and reduction of reperfusion 

injury during cardia bypass surgery. 

Acetylcysteine is not a stable molecule and is oxidized and 

degraded when in solution and exposed to air. Several U.S. 

patents have addressed this problem. For example, U.S. Pat. 

No. 5,691,380 appears to describe the use of a topical silicone-based emulsion system to improve the stability of acetyl cysteine. 

Other U.S. patents appear to address the problem by using 

2 

example disodium EDTA, tetrasodium EDTA, dipotassium 

EDTA, and calcium disodium EDTA. 

U.S. Pat. No. 5,807,894, for instance, appears to describe 

the use of the chelating agent EDTA to improve the high 

reactivity of acetylcysteine in a syrup formulation. U.S. Pat. 

No. 6,114,387 appears to describe the use ofEDTA to stabilize acetylcysteine in a solid dosage form. Aqueous solutions 

of acetylcysteine on the market, such as those under the trade 

names ofAcetadote®, Mucomyst®, Parvolex®, Fluimucil®, 

10 also contain EDTA, in the form of the salt disodium edetate 

which aids in stabilizing the pharmaceutical product. ' 

While improving the stability of acetylcysteine formulations, chelating agents such as EDTA can cause undesirable 

effects when administered to humans or animals. Some of 

15 these undesirable effects include a significant drop in serum 

calcium levels (Handbook of Pharmaceutical Excipients 226 

(R. Rowe et a!. eds., 4'h ed., 2003)), which may result in 

fatality, hypokalemia, hypomagnesemia, hypotension, and 

EDTA has also been shown to produce reproductive develop20 mental toxicity in test animals. EDTA has also been associated with dose-related bronchoconstriction when used as a 

preservative in nebulizer solutions. Id. Based on the adverse 

effects ofEDTA, particular care should be taken when administering EDTA to patients with renal impairment, liver toxic25 ity, tuberculosis, and impaired cardiac function. Id. 

Since acetylcysteine may be used to prevent or treat a 

variety of disorders and conditions, including liver damage, 

the addition of a chelating agent such as EDTA to an acetylcysteine pharmaceutical product is of concern. Chelating 

30 agents, while stabilizing the acetyl cysteine composition, may 

also decrease the effectiveness of the composition. In addition, some individuals are allergic to chelating agents such 

that they cannot receive acety !cysteine compositions containing a chelating agent or may require additional care after 

35 receiving such compositions. 

It would therefore be desirable to have a stable acetylcysteine solution drug product that does not produce adverse 

effects upon administration. In certain conditions, such as the 

use of acetylcysteine to lessen or prevent the liver damage 

40 caused by acetaminophen overdose, removing EDTA or other 

chelating agents could improve efficacy by limiting any additionalliver toxicity resulting from the chelating agent. 

SUMMARY OF THE INVENTION 

It has been surprisingly found that an aqueous composition 

containing acetylcysteine, sterilized water, and a pH-adjusting agent, is stable without the addition of a chelating agent. 

Thus, the present invention relates to a solution containing 

a chelating agent to stabilize the acetylcysteine. Chelating 

agents, or chelators, are organic agents that bond with and 45 

thereby sequester free metal ions from solution. A widely 

used chelator is edetic acid or ethylenediaminetetraacetic 

acid, commonly referred to as EDTA, which has a molecular 

weight of 292.24 and the following chemical structure: 50 acetylcysteine, which is substantially free of chelating agents. 

(Merck Index 13'h ed., n3546, pages 620-621 ). EDTA is available commercially as the free acid and as various salts, for 

55 

60 

The pH of the aqueous pharmaceutical composition of the 

invention may be from 5 to 9, from 6 to 8, from 6.5 to 7 .0, or 

6.8. The pH of the composition may be adjusted by the addition of a pH -adjusting agent, such as sodium hydroxide. 

In one embodiment of the present invention the aqueous 

pharmaceutical composition is substantially free of chelating 

agents. In a further embodiment of the present invention, the 

aqueous pharmaceutical composition is substantially free of 

EDTA, or pharmaceutically acceptable salts thereof. 

In further embodiments of the invention, the aqueous pharmaceutical composition contains less than 0.05%, less than 

0.02%, or no chelating agents. In still other embodiments of 

the invention, the aqueous pharmaceutical composition contains less than 0.05%, less than 0.02%, or no EDTA or phar65 maceutically acceptable salts thereof. 

In yet another embodiment of the invention, the aqueous 

pharmaceutical composition consists of from 10 to 400 

Case: 1:12-cv-03846 Document #: 1-1 Filed: 05/17/12 Page 3 of 7 PageID #:9
US 8,148,356 B2 

3 

mg/mL acetylcysteine and an adequate amount of sodium 

hydroxide, dissolved in deaerated water, to achieve a final pH 

from 6 to 8. 

Another embodiment of the present invention is a method 

of making an aqueous pharmaceutical composition comprising acetyl cysteine, wherein the pH of the composition is from 

6 to 8 and wherein the composition contains less than 0.05% 

chelating agents or is substantially free of chelating agents, 

such as EDTA. 

Still other embodiments of the present invention are to 

methods of treating acetaminophen overdose, liver failure, 

various cancers, methacrylonitrile poisoning, reduction of 

radiocontrast-induced nephropathy, reduction of reperfusion 

injury during cardia bypass surgery, and diseases where a 

mucolytic is desired comprising administering an aqueous 

pharmaceutical composition comprising acetylcysteine, 

wherein the pH of the composition is from 6 to 8 and wherein 

the composition contains less than 0.05% chelating agents or 

is substantially free of chelating agents, such as EDTA. 

Additional objects and advantages of the invention will be 

set forth in part in the description which follows, and in part 

will be obvious from the description, or may be learned by 

practice of the invention. The objects and advantages of the 

invention will be realized and attained by means of the elements and combinations particularly pointed out in the 

appended claims. 

It is to be understood that both the foregoing general 

description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. 

DETAILED DESCRIPTION OF THE INVENTION 

A. Definitions 

In order that the present invention may be more readily 

understood, certain terms are first defined. Additional definitions are set forth throughout the detailed description. 

The term "stable" or "stability" refers to both the physical 

and chemical stability of a composition in any form, such as 

a solution. A composition is stable if it exhibits minimal 

change overtime relative to when it is manufactured. Stability 

is measured at various time points through a planned product 

expiration date with evaluation criteria including such items 

as therapeutic activity, appearance, levels of particulate matter, pH, content of active ingredient(s ), and levels of degradation products, impurities, or related substances. The stability of a composition can be measured as described in Example 

3. 

4 

tion, but may be present otherwise. For instance, the chelating 

agent may be present as an impurity or undesired contaminant. 

B. Description of the Invention 

The Applicant has discovered that liquid compositions of 

acetylcysteine can be produced with pharmaceutically 

acceptable stability in solution of at least one year at ambient 

10 conditions and six months at accelerated conditions (40° C.) 

without the need of a chelating agent. This stability is surprising given the generally unstable nature of acetyl cysteine. 

Chelating agents, or chelators, are organic agents that bond 

with and thereby sequester free metal ions from solution. A 

15 widely used chelator is edetic acid or ethylenediaminetetraacetic acid, commonly referred to as EDTA. Additional 

examples of chelating agents include, but are not limited to, 

diethylenetriaminepentaacetic acid (DTPA), triethylenetetraaminehexaacetic acid (TTHA), trans-! ,2-diaminocyclo20 hexane-N,N,N',N'-tetraacetic acid (CDTA), ethylenediaminedisuccinic acid (EDDS), dihydroxyethyl glycine, citric 

acid, succinic acid, and tartaric acid A chelator may be used in 

its acid form, but it may also be used as one of its salts. Salts 

of EDTA, for example, include edetate calcium disodium, 

25 edetate disodium, edetate sodium, edetate trisodium, and edetate dipotassium. 

In one embodiment, the compositions of the invention 

contain no chelating agents or are substantially free of chelating agents, such as EDTA. In another embodiment the com30 positions of the invention contain less than 0.05% of a chelating agent, such as EDTA. For example, the composition of the 

present invention may contain less than 0.050%, 0.045%, 

0.040%, 0.035, 0.030%, 0.025%, 0.020%, 0.015%, 0.010%, 

0.0050%, 0.0025%, 0.0010% of chelating agents, such as 

35 EDTA. 

Acety !cysteine is the nonproprietary name for theN -acety I 

derivative of the naturally occurring amino acid, L-cysteine 

(also known as N-acetyl-L-cysteine and NAC). In one 

embodiment of the invention, the aqueous compositions of 

40 the invention comprise an effective amonnt of acetyl cysteine. 

Acetylcysteine includes derivatives of acetylcysteine, and 

pharmaceutically acceptable salts thereof. Derivatives of acetylcysteine include, but are not limited to, esters, amides, 

anhydrides, and thio-esters and thio-ethers of the sulfhydryl 

45 moiety. Pharmaceutically acceptable salts of acetylcysteine 

and acetyl cysteine derivatives include, but are not limited to, 

sodium salts, potassium salts, magnesium salts, calcium salts, 

zinc salts, and ammonium salts. 

The amount of acetyl cysteine may vary depending on the 

50 desired characteristics of the solution and can be determined 

by one of ordinary skill in the art. In one embodiment of the 

invention, the acetylcysteine comprises 0.1-50%, in another 

embodiment 1.0-25%, in an additional embodiment 10%, and 

As used herein, the term "salt" or "pharmaceutically 

acceptable salt" refers to acidic salts formed with inorganic 

and/or organic acids, as well as basic salts formed with inorganic and/or organic bases. Examples of these acids and bases 55 

are well known to those of ordinary skill in the art. Salts 

according to the present invention may be used in a variety of 

forms. In water and other aqueous solutions, salts typically 

dissociate into an "anion," or negatively charged subcomponent, and a "cation," or positively charged subcomponent. 

The salts may also be those that are physiologically tolerated 

in yet another embodiment 20%. 

The present inventor has further discovered that a liquid 

composition of acetylcysteine can be produced, which is substantially free of or contains less than 0.05% chelating agents, 

which has a pH that is suitable for injection or inhalation and 

can also be used orally. Thus, another embodiment of the 

60 invention is a pharmaceutical composition comprising an 

aqueous solution of acetylcysteine, wherein the pH of the 

composition is from 5 to 9. In yet another embodiment of the 

invention, the pharmaceutical composition comprises an 

aqueous solution of acetylcysteine, wherein the pH of the 

by a patient, for example without nndue toxicity, incompatibility, instability, and allergic response. 

The term "substantially free" refers to compositions that 

have significantly reduced levels of chelating agents. In one 

embodiment, chelating agents are not added to the composi65 composition is from 6 to 8. A further embodiment of the 

invention is a pharmaceutical composition comprising an 

aqueous solution of acetyl cysteine, wherein the pH is about 

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US 8,148,356 B2 

5 

6.8. In still other embodiments, the pH of the composition is 

5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 

6.4, 6.5, 6.6, 6.7, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 

7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, or 9.0. 

6 

patient in need thereof an effective amount of a pharmaceutical composition comprising an aqueous solution of acetylcysteine, wherein the composition is substantially free of or 

contains less than 0.05% EDTA, or pharmaceutically acceptable salts thereof. Other conditions alleviated by the aqueous 

acetylcysteine compositions of the invention include, but are 

not limited to, liver failure, various cancers, methacrylonitrile 

poisoning, reduction of radio contrast induced nephropathy, 

reduction of reperfusion injury during cardia bypass surgery, 

Formulations of the present invention may further comprise pH-adjusting agents, for example, basic agents. Such 

agents include a number of inorganic or organic bases which 

are pharmaceutically acceptable, in the dosage ranges used, 

including a monovalent metal alkali and/or a divalent metal 

alkali, such as, for example, sodium hydroxide solution, 

potassium hydroxide solution, calcium hydroxide, magnesium hydroxide, ammonia, tertiary sodium phosphate, 

diethanolamine, ethylenediamine, N-methylglucamine, or 

L-lysine and/or mixtures thereof. In one embodiment of the 

invention sodium hydroxide is added to the composition to 

adjust the pH of the composition. 

10 and diseases where a mucolytic is desired. 

The pharmaceutical compositions of the invention may be 

administered by injection (intravenous or intramuscular), by 

inhalation, or by the oral route. In one embodiment of the 

invention, the composition of the invention is dissolved in an 

The amount of pH -adjusting agent may vary depending on 

the desired pH of the composition and the amount of acetylcysteine in the solution and can be determined by one of 

ordinary skill in the art. For example, in general, the amount 

of a pH-adjusting agent, such as sodium hydroxide, in formulations of the present invention will directly vary depending 

15 aqueous solution containing at least one of dextrose and 

sodium chloride prior to administration. In another embodiment of the invention, the composition of the invention is 

dissolved in an aqueous solution of0.45% or 0.90% sodium 

chloride (half normal and normal saline respectively). In yet 

on the desired concentration of the acetylcysteine. The exact 

amount of pH -adjusting agent to be employed will depend on 

the particular agent and upon the buffering capacity of the 

aqueous medium and other components of the formulation 

employed. Thus, the artisan will appreciate that the optimum 

amount of pH -adjusting agent will be readily determined, for 

example, by a process of titration to the desired pH. 

20 another composition of the invention, it is dissolved in an 

aqueous solution of 5% dextrose prior to administration. The 

composition of the invention may also be dissolved in water 

for injection prior to administration. Other diluents known to 

those of ordinary skill in the art can also be used. Dosages of 

25 the pharmaceutical composition range from 10 mg per dose to 

as much as 400 mg/kg of acety !cysteine in the pharmaceutical 

composition and can be determined by one of ordinary skill in 

the art. 

The present invention also provides for an aqueous phar- 30 

maceutical composition consisting of from 10 to 400 mg/mL 

acetylcysteine and the titrated amount of sodium hydroxide 

or other base, dissolved in deaerated water, to achieve the 

desired pH of the composition, for example from 6 to 8. 

In certain embodiments, the pharmaceutical composition 35 

may contain formulation materials for modifying, maintaining or preserving, for example, osmolarity, viscosity, clarity, 

color, isotonicity, odor, sterility, rate of dissolution or release, 

adsorption or penetration of the composition. In certain 

embodiments, suitable formulation materials include, but are 40 

not limited to, antioxidants (such as ascorbic acid or sodium 

metabislfuite); bulking/caking agent (such as mannitol, lactose, or trehalose); excipients and/or pharmaceutical adjuvants. (Remington's Pharmaceutical Sciences, 18'h Edition, 

In one embodiment the invention, the pharmaceutical composition is administered to treat acetaminophen toxicity. The 

composition of the invention is mixed in 5% dextrose and 150 

mg/kg of drug is given over a period of 15 minutes to 2 hours 

as a loading dose immediately followed by a second dose at 

50 mg/kg over 4 hours and then by a third dose of 100 mg/kg 

over 20 hours. Additional courses can be given if required. 

One of skill in the art will recognize that the appropriate 

dosage of the aqueous acetylcysteine compositions may vary 

depending on the individual being treated and the purpose. 

For example, the age, body weight, and medical history of the 

individual patient may affect the efficacy of the therapy. Further, a lower dosage of the composition may be needed to 

treat, for instance, lower weight patients, while heavier 

patients require a higher dose of acetylcysteine. A competent 

physician can consider these factors and adjust the dosing 

A. R. Gennaro, ed., Mack Publishing Company (1990). 45 regimen to ensure the dose is achieving the desired therapeutic outcome without undue experimentation. It is also noted 

that the clinician and/or treating physician will know how and 

when to interrupt, adjust, and/or terminate therapy in conThe present inventor has further discovered a method of 

making a pharmaceutical composition comprising an aqueous solution of acetylcysteine and a pH-adjusting agent, 

wherein the composition is substantially free of chelating 

agents or contains less than 0.05% chelating agents. The 50 

method comprises the following; adding acetylcysteine to 

deaerated water, adding a pH-adjusting agent until a pH of 

approximately 6.8 is reached and the acetylcysteine is fully 

dissolved. Alternatively, acetylcysteine can be added to an 

aqueous deaerated solution containing the pH adjusting solu- 55 

tion. The resulting product is a clear, colorless to light purple 

solution that can be readily passed through a sterilizing filter, 

such as a 0.2 micron filter. The product is then filled into vials 

and an inert atmosphere is placed over the solution prior to 

sealing. One of ordinary skill in the art will recognize meth- 60 

ods of varying the manufacturing process to optimize the 

dosage form or increase the product amount for large-scale 

manufacturing. 

Acetylcysteine administration has been shown to reduce 

the extent ofliver injury following acetaminophen overdose. 65 

The present inventor has discovered a method of treating 

acetaminophen overdose comprising administering to a 

junction with individual patient response. 

All references cited herein are incorporated herein by reference in their entirety and for all purposes to the same extent 

as if each individual publication or patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety for all purposes. To the 

extent publications and patents or patent applications incorporated by reference contradict the disclosure contained in 

the specification, the specification is intended to supersede 

and/or take precedence over any such contradictory material. 

All numbers expressing quantities of ingredients, reaction 

conditions, and so forth used in the specification and claims 

are to be understood as being modified in all instances by the 

term "about." Accordingly, unless indicated to the contrary, 

the numerical parameters set forth in the specification and 

attached claims are approximations that may vary depending 

upon the desired properties sought to be obtained by the 

present invention. At the very least, and not as an attempt to 

limit the application of the doctrine of equivalents to the scope 

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US 8,148,356 B2 

7 

of the claims, each numerical parameter should be construed 

in light of the number of significant digits and ordinary rounding approaches. 

All numbers expressing percentages of ingredients, components, and so forth used in the specification and claims are 

to be understood as being modified in all instances by the term 

"w/v." Accordingly, unless indicated to the contrary, the percentages set forth in the specification and attached claims are 

expressed in weight per unit volume. 

8 

ofdeaerated water for injection to make a 10% solution (total 

volume of 100 liters). Minimize exposure to air by displacing 

oxygen with nitrogen or other pharmaceutically inert gas. 

Pass the solution through a 0.2 micron or other sterilizing 

filter. Fill the product into vials or ampules minimizing exposure to oxygen by displacing the headspace with nitrogen or 

other pharmaceutically inert gas. 

Example 3 

Many modifications and variations of this invention can be 10 

made without departing from its spirit and scope, as will be 

apparent to those skilled in the art. The specific embodiments 

described herein are offered by way of example only and are 

not meant to be limiting in any way. It is intended that the 

specification and examples be considered as exemplary only, 15 

with a true scope and spirit of the invention being indicated by 

the claims. 

Stability of Acetylcysteine Compositions of the 

Invention 

To determine whether the stability of acetyl cysteine solutions required EDTA, three solutions containing different 

concentrations of edetate disodium were manufactured. The 

stability of a solution containing 0.05% edetate disodium, a 

solution containing 40% of that amount, 0.02% edetate disodium, and a solution containing no edetate disodium (0.00%) 

was examined. The three solutions were manufactured using 

The following examples represent specific embodiments 

of the foregoing discovery, and they are not representative of 

the entire scope of the invention. The acetylcysteine, water, 

sodium hydroxide, and disodium edentate are Pharmacopea 

grade but other pharmaceutically acceptable materials can be 

utilized. 

C. Examples 

The following examples are offered for illustrative purposes only. 

Example 1 

Preparation of an Acetyl cysteine Formulation 

Twenty kilograms of acetyl cysteine were added to appro ximately 60 liters of deaerated water for injection and the solution was mixed. A solution of sodium hydroxide was added to 

adjust the pH to approximately 6.5 to 7.0 and mixed until 

dissolved. A sufficient quantity of deaerated water for injection was added to make a 20% solution (total volume of 100 

liters). Exposure to air was minimized by displacing oxygen 

with nitrogen. The solution was passed through a 0.2 micron 

sterilizing filter. The product was filled into vials or ampules 

and exposure to oxygen minimized by displacing the headspace with nitrogen. 

Example 2 

Preparation of an Acetyl cysteine Formulation 

Add 10 kg of acetylcysteine to approximately 60 liters of 

deaerated water for injection and mix. Add a solution of 

sodium hydroxide to adjust the pH to approximately 6.5 to 7.0 

and continue mixing until dissolved. Add a sufficient quantity 

Disodiwn 

20 similar processes to the process described in Example 1. 

Briefly, the edetate disodium, if any, was added in approximately 60% of the required deaerated water and mixed until 

dissolved. Acetylcysteine was then added and mixed until 

dissolved. The pH was adjusted to approximately 6.8 with 

25 sodium hydroxide and deaerated water was added to the 

target level. Nitrogen was used to purge the solutions. The 

product was then passed through a 0.2 micron filter to remove 

potential microbial contamination and was filled into vials. 

At an initial time point, high performance liquid chroma30 tography (HPLC) was used to assess the acetylcysteine content and chromatographic purity of the three solutions. Measurements were taken of various impurities including, 

L-cysteine, impurity C, (disulfide), impurity D, and other 

impurities or degradation products. The peak areas for these 

35 HPLC measurements are presented in Table 1. An analysis of 

unknown peaks in the chromatograms was also undertaken. 

The "highest unknown" represents the area of the highest 

individual unidentified peak in the chromatogram, while 

"total unknowns" represents the total area of unidentified 

40 peaks in the chromatogram. See Table 1. In addition to HPLC, 

the visual appearance, pH, and levels of particulates of each 

of the three solutions were examined. Vials containing the 

three solutions were then placed at either 25° C. or 40° C. and 

vials were removed at 3 months, 6 months, and 12 months and 

45 assayed for the parameters described above. See Table 1. 

Appearance, pH, and particulate matter remained constant 

over time between the three formulations. As shown in Table 

1, there were no significant differences between each of the 

three solutions in acetylcysteine content or purity. The results 

so demonstrate that edetate is not required to produce a product 

with pharmaceutically acceptable stability. These results are 

surprising given the generally unstable nature of acetylcysteine. 

TABLE 1 

Acetylcysteine L- Impurity C Highest Total 

Time-point EDTA Temp Content Cysteine (Disulfide) Impurity D Unknown Unknowns 

Initial 0.00% N!A 202.4 0.15 0.55 0.18 0.01 0.02 

Initial 0.02% N!A 203.9 0.19 0.44 0.23 0.03 0.05 

Initial 0.05% N!A 204.7 0.20 0.50 0.30 0.04 0.10 

3 Months 0.00% 25° C. 204.2 0.181 0.482 0.137 0.053 0.080 

3 Months 0.00% 40° C. 201.8 0.370 0.540 0.90 0.070 0.132 

3 Months 0.02% 25° C. 204.9 0.259 0.436 0.191 0.074 0.141 

3 Months 0.02% 40° C. 204.5 0.463 0.467 0.142 0.065 0.183 

3 Months 0.05% 25° C. 206.1 0.299 0.444 0.214 0.044 0.119 

3 Months 0.05% 40° C. 205.4 0.532 0.507 0.165 0.045 0.154 

Case: 1:12-cv-03846 Document #: 1-1 Filed: 05/17/12 Page 6 of 7 PageID #:12
US 8,148,356 B2 

9 10 

TABLE !-continued 

AcetylDisodiwn cysteine L- Impurity C Highest Total 

Time-point EDTA Temp Content Cysteine (Disulfide) Impurity D Unknown Unknowns 

6 Months 0.00% 25° C. 202.4 0.262 0.523 

6 Months 0.00% 40° C. 201.7 0.707 0.509 

6 Months 0.02% 25° C. 205.9 0.338 0.391 

6 Months 0.05% 25° C. 207.1 0.369 0.483 

6 Months 0.05% 40° C. 204.6 0.932 0.509 

6 Months 0.02% 40° C. 204.3 0.856 0.525 

12 Months 0.00% 25° C. 204.5 0.364 0.597 

12 Months 0.02% 25° C. 206.0 0.435 0.475 

12 Months 0.05% 25° C. 207.1 0.514 0.435 

I claim: 

1. A stable aqueous pharmaceutical composition comprising between 200 and 250 mg/mL acetylcysteine, wherein the 

composition is free from a chelating agent, or pharmaceutically acceptable salts thereof, wherein said composition is in 

a suitable form for intravenous injection, wherein the pH of 

the composition is from 6 to 7, and wherein said composition 

is sealed in an airtight container comprising a fill volume of 

said composition and a headspace volume occupied by a 

pharmaceutically inert gas. 

2. The aqueous pharmaceutical composition of claim 1, 

wherein the composition contains no EDTA, or pharmaceutically acceptable salts thereof. 

0.106 0.013 0.013 

0.053 0.133 0.133 

0.167 0.013 0.013 

0.186 0.013 0.013 

0.104 0.135 0.135 

0.093 0.135 0.135 

0.079 0.034 0.071 

0.134 0.042 0.130 

0.160 0.055 0.122 

15 8. An aqueous pharmaceutical composition consisting of 

between 200 and 500 mg/mL acetylcysteine, or pharmaceutically acceptable salts thereof, dissolved in deaerated water 

and wherein the pH of the composition is adjusted with ~ 

20 pH-adjusting agent to a pH of from 6 to less than 7, wherein 

said composition is in a suitable form for intravenous injection and is free of a chelating agent, and wherein said composition is sealed in an airtight container comprising a fill 

volume of said composition and a headspace volume occu25 pied by a pharmaceutically inert gas. 

9. A container comprising: 

3. The aqueous pharmaceutical composition of claim 1, 

wherein the pH of the composition is from 6.5 to less than 7 .0. 30 

4. The aqueous pharmaceutical composition of claim 3, 

wherein the pH of the composition is 6.8. 

an aqueous pharmaceutical composition comprising 

between 200 and 500 mg/mL acetylcysteine, wherein 

the composition is free of a chelating agent and has a pH 

of about 6 to less than 7, or pharmaceutically acceptable 

salts thereof, and wherein said composition is in a suitable form for intravenous injection; and 

a headspace consisting essentially of a pharmaceutically 

inert gas. 

5. The aqueous pharmaceutical composition of claim 1, 

wherein the composition is stable for at least 12 months at 25° 

C. 35 10. The container of claim 9, wherein the pharmaceutically 

inert gas is nitrogen. 6. The aqueous pharmaceutical composition of claim 1, 

wherein the composition is stable for at least 6 months at 40° 

C. 

7. An aqueous pharmaceutical composition consisting of 

between 200 and 250 mg/mL acetylcysteine, or pharmaceu- 40 

tically acceptable salts thereof dissolved in deaerated water 

and wherein the pH of the composition is adjusted with ~ pH-adjusting agent to a pH of from 6 to less than 7, wherein 

said composition is in a suitable form for intravenous injection and is free of a chelating agent, and wherein said com- 45 

position is sealed in an airtight container comprising a fill 

volume of said composition and a headspace volume occupied by a pharmaceutically inert gas. 

11. The composition of claim 1, wherein the composition 

has a substantially constant acetyl cysteine amount through at 

least 3 months of storage. 

12. The composition of claim 1, wherein the composition 

has a substantially constant acetyl cysteine amount through at 

least 12 months of storage. 

13. The composition of claim 1, wherein the acetylcysteine 

amount through at least 12 months of storage is at least 99% 

of the original amount. 

14. The composition of claim 9, wherein the chelating 

agent is EDTA. 

* * * * * 

Case: 1:12-cv-03846 Document #: 1-1 Filed: 05/17/12 Page 7 of 7 PageID #:13