STABILIZATION OF EPINEPHRINE FORMULATIONS

Abstract

The disclosure herein relates to the innovative epinephrine formulations in aqueous solution of medicinal products that enhance the physicochemical stabilities of epinephrine and extend the product shelf life. In some instances, the formulations comprise epinephrine or a salt thereof, a complexing agent, and a “non-sulfite” antioxidant. The epinephrine formulations substantially demonstrated the superior physicochemical stabilities to conventional sulfite formulation of commercial medications currently available. In some instances, sulfite-free formulations further provide further benefit (e.g., safety benefits) to sulfite-sensitive patients. The compositions, methods for preparing the formulations, and methods of using the same (e.g., in the treatment of anaphylaxis) are also provided.

Claims

1. A pharmaceutical composition comprising: l-epinephrine; one or more antioxidant, the antioxidant being present in the composition in an amount of about 0.005 wt. % to about 0.07 wt. %, wherein the one or more antioxidant comprises cysteine, acetylcysteine, thioglycerol, or any combination thereof; and an aqueous medium; wherein the pharmaceutical composition has a pH of at least 3.5.

2. A pharmaceutical composition comprising: l-epinephrine; and cysteine, the cysteine being present in the composition in a cysteine to l-epinephrine weight ratio of about 7:10 or less.

3. (canceled)

4. The pharmaceutical composition of claim 1, wherein the one or more antioxidant is cysteine.

5. The pharmaceutical composition of claim 1, wherein the antioxidant is present in a concentration of about 0.005 wt. % to about 0.035 wt. %.

6. The pharmaceutical composition of claim 4, wherein the antioxidant is present in a concentration of about 0.005 wt. % to about 0.03 wt. %.

7. The pharmaceutical composition of claim 1, wherein (i) after six months of storage at 40±2° C. and 75±5% relative humidity (RH), the composition comprises at least 90 wt. % of the l-epinephrine in the composition prior to storage; (ii) after 12 months of storage at 25±2° C. and 60±5% relative humidity (RH) the composition comprises at least 90 wt. % of the l-epinephrine in the composition prior to storage; and (iii) after 12 months of storage at 25±2° C. and 60±5% relative humidity (RH) the composition is substantially colorless.

8. The pharmaceutical composition of claim 6, wherein after at least 1 year of storage at 25° C./60% RH, less than 10% of the l-epinephrine is d-epinephrine.

9. The pharmaceutical composition of claim 1, wherein the l-epinephrine is present in the composition in an amount of about 0.01 wt. % to about 1 wt. % on a free base basis.

10. The pharmaceutical composition of claim 6, wherein the l-epinephrine is present in the composition in an amount of about 0.05 wt. % to about 0.15 wt. % on a free base basis.

11. The pharmaceutical composition of claim 1, further comprising a complexing agent, wherein the complexing agent is one or more cyclodextrin.

12. The pharmaceutical composition of claim 11, wherein the cyclodextrin is present in the composition in a molar ratio of cyclodextrin-to-l-epinephrine of about 1:10 to about 10:1.

13. The pharmaceutical composition of claim 12, wherein the cyclodextrin is present in the composition in a molar ratio of cyclodextrin-to-l-epinephrine of about 1:3 to about 2:1.

14. The pharmaceutical composition of claim 1 wherein the antioxidant is present in the composition in a weight ratio of antioxidant to l-epinephrine of about 7:10 or less.

15. The pharmaceutical composition of claim 1, further comprising one or more pH buffering agent, the combined weight of pH buffering agent(s) constituting about 0.01 wt. % or less of the composition.

16. The pharmaceutical composition of claim 1, further comprising an edetate, the edetate being present in the composition in an amount of about 0.01 wt. % or less.

17. The pharmaceutical composition of claim 1, wherein a tonicity modifier is present in the composition in an amount suitable to provide a solution osmolality in the range of about 200 mOsm/kg to about 400 mOsm/kg.

18. The pharmaceutical composition of claim 1, wherein the composition is an aqueous solution having a pH of about 3.5 to about 6.5.

19-20. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0083] FIG. 1 demonstrated the fraction of epinephrine complex with SBEβCD at pH 3.5 (K=488 M.sup.−1) and pH 5.5 (K=111 M.sup.−1).

[0084] FIG. 2 illustrates an HPLC chromatogram of epinephrine degradation in a presence of 1:1 weight ratio of cysteine-to-drug at pH 2.5 after 1 month at 50° C.

[0085] FIG. 3 illustrates an HPLC chromatogram of epinephrine stability in SBEβCD formulation containing 1:10 weight ratio of cysteine-to-drug after 1 month at 50° C.

[0086] FIG. 4 illustrates an HPLC chromatogram of epinephrine stability in HPβCD formulation containing 1:10 weight ratio of cysteine-to-drug after 1 month at 50° C.

[0087] FIG. 5 illustrates an HPLC chromatogram of epinephrine stability in non-complex formulation containing 1:10 weight ratio of cysteine-to-drug after 1 month at 50° C.

[0088] FIG. 6 illustrates the HPLC chromatogram of epinephrine stability in SBEβCD formulation after 6 months at 40° C.

[0089] FIG. 7 illustrates the HPLC chromatogram of epinephrine stability in HPβCD formulation after 6 months at 40° C.

[0090] FIG. 8 illustrates the HPLC chromatogram of epinephrine chirality in SBEβCD formulation after 3.5 months at 40° C.

[0091] FIG. 9 illustrates the HPLC chromatogram of epinephrine chirality in HPβCD formulation after 3.5 months at 40° C.

DETAILED DESCRIPTION OF THE INVENTION

[0092] In order to prevent the thermal and/or oxidative degradations of epinephrine, commercial formulations available on the market are currently using a common conventional antioxidant of sulfite related compounds such as sodium bisulfite and/or sodium metabisulfite etc. The examples of marketed products of epinephrine auto injectors for anaphylaxis treatment include EpiPen®, Twinject®, Adenaclick® and Auvi-Q™. The sulfite related compounds can directly react with epinephrine, resulting in a substantial loss of epinephrine potency and generating degradation products, such as epinephrine sulfonic acid (ESA), which rapidly increases with time and becomes a major limiting factor to the product shelf life.

[0093] In some instances, sulfite related compounds in foods and/or medications cause a severe allergy or asthma reaction. For instance, some people have experienced severe reactions from sulfite-containing medications including intravenous drugs and inhaled medications, these reactions including flushing, hives, and a drop in lung function. The present invention provides the compositions of a “sulfite free” formulation of epinephrine, which significantly improves the product stability and eliminates the patient's risk of a potential exposure to a severe allergy or asthma reaction from the aforementioned antioxidant of sulfite related compounds.

[0094] In certain embodiments, present invention provides compositions and methods of using a novel formulation to enhance the physicochemical stability of epinephrine in an aqueous solution and subsequently extend the product shelf life. In some embodiments, the invention also provides a safer medication for patients by reducing and/or eliminating additives, such as a conventional “sulfite” antioxidant, in the formulation that degrade the epinephrine potency, generates degradation products, and potentially causes the subsequent severe asthma and/or allergy reactions. In some embodiments, compositions provided herein reduce a patient's risk of exposure to unwanted degradation products (e.g., high ESA levels and unnecessary asthma and/or allergy reactions associated therewith), a patient's risk of exposure to drastic dosage overages and/or underages depending on the manufacture date of the product, a patient's exposure to unnecessary additives and agents, etc.

[0095] In certain embodiments provided herein are pharmaceutically acceptable compositions comprising epinephrine and any one or more excipients. In specific embodiments, compositions provided herein comprise epinephrine and a complexing agent, an antioxidant, a pH buffering agent, a chelating agent, a tonicity modifier, or any combination thereof. In more specific embodiments, provided herein are compositions comprising epinephrine and an antioxidant (e.g., cysteine, acetylcysteine, thioglycerol, or any combination thereof). In more specific embodiments, provided herein are compositions comprising epinephrine, a complexing agent (e.g., a cyclodextrin), and an antioxidant (e.g., cysteine, acetylcysteine, thioglycerol, or any combination thereof). In one embodiment, the pharmaceutical formulation comprises of epinephrine (e.g., formulated as a free base or a pharmaceutically acceptable salt thereof), a complexing agent, an antioxidant, a pH buffering agent, a chelating agent and a tonicity modifier in an aqueous based media. In another embodiment, the pharmaceutical formulation comprises of epinephrine (e.g., formulated as a free base or a pharmaceutically acceptable salt thereof), an antioxidant, a pH buffering agent, a chelating agent and a tonicity modifier in an aqueous based media.

[0096] In various embodiments, compositions provided herein are optionally formulated with any suitable epinephrine, such as the free base, conjugate acid, or a pharmaceutically acceptable salt thereof. In specific embodiments, the epinephrine utilized to formulate a composition provided herein is selected from epinephrine (free base), epinephrine bitartrate, and epinephrine hydrochloride and/or a combination thereof. Generally, compositions described herein as comprising epinephrine refer to a dissolved epinephrine, whether dissolved free base, conjugate acid, or a salt thereof. Compositions provided herein optionally comprise epinephrine in the free base form and/or in a protonated cation (conjugate acid) or salt form. In some embodiments, the epinephrine is provided in a composition herein and/or formulated into a composition herein in a free base equivalent amount of about 0.0001 wt. % to about 5 wt. %. In some instances, concentrations vary with varying therapeutic treatments and/or administration routes. In specific embodiments, compositions provided herein comprise about 0.0001 wt. % to about 1 wt. % epinephrine (e.g., for injectable formulations or topical formulations), about 0.5 wt. % to about 2 wt. % epinephrine (e.g., for ophthalmic drops), about 1 wt. % to about 5 wt. % (e.g., for inhalation formulations). In certain embodiments, the epinephrine is l-epinephrine or (−) epinephrine, such as at a concentration of about 0.01 wt. % to about 1.0 wt. %.

[0097] In some instances, provided herein is the use of cyclodextrin as a complexing agent to chemically form an inclusion complex with epinephrine. In various embodiments herein, any suitable complexing agent is optionally utilized, such as a native and/or modified cyclodextrin derivative. In specific embodiment, a cyclodextrin utilized in a formulation provided optionally includes, e.g., a α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, modified α-cyclodexin, modified β-cyclodextin, modified γ-cyclodextrin, and/or a combination thereof. In certain embodiments, the complexing agent is utilized in a composition herein in a molar ratio of about 1:10 to about 10:1 of cyclodextrin to epinephrine. In some embodiments, preferred cyclodextrins include, by way of non-limiting example, modified β-cyclodextins, such as hydroxypropyl β-cyclodextrin (Kleptose® HPB, Kleptose® HP, Trappsol® HPB), sulfobutyl ether β-cyclodextrin (Captisol®), randomly methylated β-cyclodextrin (Kleptose® Crysmeb Exp), or a combination thereof. In specific embodiments, the compositions comprise and/or are formulated with a complexing agent (e.g., cyclodextrin) at a molar ratio of about 1:10 to about 2:1, such as about 1:3 to about 2:1 molar ratio, of cyclodextrin to epinephrine

[0098] Cyclodextrins (sometimes called cycloamyloses) are a family of compounds made up of sugar molecules bound together in a ring (cyclic oligosaccharides). For example, sulfobutylether β-cyclodextrin (SBEβCD) is a polyanionic beta-cyclodextrin derivative with a sodium sulfonate salt separated from the lipophilic cavity by a butyl ether spacer group, or sulfobutylether. SBEβCD is not a single chemical species, but comprised of a multitude of polymeric structures of varying degrees of substitution and positional/regional isomers. SBEβCD is an approved pharmaceutical ingredient for commercial injectable products. Hydroxypropyl β-cyclodextrin (HPβCD) is the most widely used modified β-cyclodextrin with the lipophilic cavity formed by 7 glucose units. HPβCD has the most extensive collection of safety data in the technical literature with no adverse reactions reported, and is approved for use for injectable products and parenteral products.

[0099] While not being bound by any theory, examples of association constants (K) of the inclusion complex between epinephrine and SBEβCD in aqueous solution were reported 488 M.sup.−1 and 111 M.sup.−1 at pH 3.5 and 5.5, respectively (US 2015/0374832 A1). The K value can be used to determine free or unbound drug in the complex solution (Rajewski, R. A. and Stella, V. J. Pharmaceutical Applications of Cyclodextrins. 2. In Vivo Drug Delivery, Journal of Pharmaceutical Sciences, 85(11), 1142-1169, 1996) as shown in Equation 1.

[00001]$\begin{array}{cc}{\mathrm{Drug}}_{free}+C{D}_{free}\stackrel{K}{\iff }\mathrm{Drug}/{\mathrm{CD}}_{complex}& \left(1\right)\end{array}$

where CD is cyclodextrin. The total solubility of epinephrine, a weakly basic drug in a presence of CD at a low pH range can be described in Equation 2.

S.sub.Total=S.sub.0+S.sub.ionic+S.sub.Complex  (2)

where S.sub.total is total drug solubility, S.sub.0 is an intrinsic solubility of drug, S.sub.ionic is an ionization solubility of drug, and S.sub.Complex is a complex solubility of drug-CD. Equation 2 can also be described in Equation 3.

[00002]$\begin{array}{cc}{S}_{\mathrm{total}}=S_0+S_{\mathrm{ionic}}+\frac{K\left[S_0+S_{ionic}\right]\left[C{D}_{\mathrm{total}}\right]}{K\left[S_0+S_{ionic}\right]+1}& \left(3\right)\end{array}$

where [CD.sub.total] is total cyclodextrin added to the solution, and K is 1:1 association constant defined by Equation 4.

[00003]$\begin{array}{cc}K=\frac{\left[\mathrm{Drug}-{\mathrm{CD}}_{comp1ex}\right]}{\left[{\mathrm{Drug}}_{free}\right]\left[C{D}_{free}\right]}& \left(4\right)\end{array}$

Since S.sub.ionic>>>S.sub.0, therefore S.sub.0+S.sub.ionic≈S.sub.ionic and Equation 3 can be rewritten by Equation 5.

[00004]$\begin{array}{cc}{S}_{\mathrm{total}}=S_{\mathrm{ionic}}+\frac{K\left[S_{ionic}\right]\left[C{D}_{\mathrm{total}}\right]}{K\left[S_{ionic}\right]+1}& \left(5\right)\end{array}$

[0100] The fraction of epinephrine in the formulation that would be in complex with CD at any once instance as determined by Equation 5 is shown in FIG. 1. This data demonstrates that epinephrine is expected to weakly complex with SBEβCD at lower pH—where in general, the K values of any drug and CD complex of 10 to 1×10.sup.3 M.sup.−1 are common, values of 1×10.sup.4 M.sup.−1 are seen occasionally, and values >1×10.sup.5 M.sup.−1 are unusual (Stella V. J. and He Q., Cyclodextrins, Toxicologic Pathology, 36(1), 30-42, 2008).

[0101] Generally, this is an important mechanism as the free drug should be immediately released from the complex after injection in order to provide its pharmacological effect. In some instances provided herein, the drug is easily released with a minimum dilution of body aqueous fluid like blood upon intramuscular or subcutaneous injection. In one illustrative example, an injection of 0.3 mL epinephrine (1:1000) in a presence of 1:2 molar ratio of SBEβCD to drug at pH 3.5 (K=488 M.sup.−1) would rapidly release 90% and 99% free drug approximately after the dilutions with 3 mL (10×) and 30 mL (100×) body aqueous fluid, respectively as summarized in TABLE 1. A similar exercise may be performed for a 0.15 mL epinephrine injection of the same above formulation for the pediatric patient where the free drug would be rapidly released ˜90% and ˜99% after the dilutions with 1.5 mL (10×) and 15 mL (100×) body aqueous fluid, respectively (TABLE 1). This conservative example assumes fixed volumes, which of course is not the case in-vivo where the drug is rapidly diffused from the injection site.

TABLE-US-00001 TABLE 1 An example of free epinephrine released from 0.15 and 0.3 mL injection of drug complex (1:1000) containing 1:2 molar ratio of SBEβCD to drug at pH 3.5 (K = 488 M.sup.−1). Dilution % Drug % Free Time (×) Volume (mL) Complex Drug 1 0.3* 0.15** 26.7 73.3 10 3 1.5 9.5 90.5 100 30 15 1.3 98.7 1000 300 150 0.1 99.9 *Injection volume for adult patient, **Injection volume for pediatric patient

[0102] However, the fraction of non-complex free drug is still susceptible to the oxidation that could cause the solution discoloration due to a weak association constant (K) of epinephrine complex. In some embodiments, compositions further comprise a “non-sulfite” antioxidant, e.g., to protect the non-complexed free drug in the formulation from the oxidation.

[0103] Unexpectedly, a new discovery of antioxidant (e.g., cysteine) level in the present invention that efficiently inhibit drug oxidation and minimize the cross reaction with drug was found at very low concentrations. Indeed, low concentrations of antioxidant (e.g., cysteine) and low weight ratios of antioxidant to drug are demonstrated herein to provide dramatically improved physiochemical stability (improved potency, reduced degradation products, and improved color profile) over time, relative to both compositions lacking antioxidant (e.g., cysteine) and compositions with higher amounts of antioxidant (e.g., cysteine).

[0104] In various embodiments, a composition provided herein comprises any suitable “non-sulfite” antioxidant (including a single antioxidant or a combination of antioxidants). In specific embodiments, “non-sulfite” antioxidants include by way of non-limiting example oxine, boric acid, borate, ascorbic acid, erythorbic acid, malic acid, acetylcysteine (N-acetylcysteine or N-acetyl-L-cysteine), thioglycerol (monothioglycerol or 1-thioglycerol), cysteine (L-cysteine), cysteine hydrochloride, citric acid, polyvinylpyrrolidone and/or any combination (of two or more) thereof. In specific embodiments, antioxidants are included in an amount of about 0.001 wt. % to about 2.6 wt. %, e.g., about 0.001 wt. % to about 0.1, about 0.001 wt. % to about 0.05 wt. %, about 0.005 wt. % to about 0.05 wt. %, about 0.001 wt. % to about 0.02 wt. %, or the like. In some embodiments, antioxidant (comprising one or more antioxidant, such as cysteine, acetylcysteine, thioglycerol, or any combination (of two or more) thereof) is present in an amount of about 0.005 wt. % to about 0.07 wt. %. In specific embodiments, antioxidant is present in an amount of about 0.01 wt. % to about 0.07 wt. %. In some embodiments, antioxidant is present in an amount of about 0.005 wt. % to about 0.05 wt. %. In specific embodiments, antioxidant is present in an amount of about 0.01 wt. % to about 0.05 wt. %. In some embodiments, antioxidant is present in an amount of about 0.015 wt. % to about 0.07 wt. %. In specific embodiments, antioxidant is present in an amount of about 0.015 wt. % to about 0.05 wt. %. In more specific embodiments, the antioxidant is present in an amount of about 0.02 wt. % to about 0.04 wt. %, such as about 0.03 wt. %.

[0105] In specific embodiments, a composition herein comprises cysteine (e.g., as the antioxidant), such as having a concentration of about 0.005 wt. % to about 0.05 wt. % (e.g., about 0.01 wt. % to about 0.04 wt. %). In some embodiments, a composition herein comprises thioglycerol (e.g., as the antioxidant), such as having a concentration of about 0.005 wt. % to about 0.07 wt. %. In some embodiments, a composition herein comprises acetylcysteine (e.g., as the antioxidant), such as having a concentration of about 0.005 wt. % to about 0.07 wt. %. In certain embodiments, the antioxidant comprises cysteine and acetylcysteine. In other embodiments, the antioxidant comprises cysteine and thioglycerol. In still other embodiments, the antioxidant comprises acetylcysteine and thioglycerol.

[0106] In further or alternative embodiments, a weight ratio of antioxidant (e.g., cysteine) to drug is less than 1:1, such as about 1:20 to about 1:2, e.g., about 1:20 to about 1:5, or the like. In specific embodiments, the weight ratio is about 1:20 to about 1:1, about 1:20 to about 7:10, about 1:20 to about 1:2, about 1:20 to about 3:10, about 1:10 to about 1:1, about 1:10 to about 7:10, about 1:10 to about 1:2, about 1:10 to about 3:10, or the like.

[0107] In some embodiments, the weight ratio of antioxidant (e.g., cysteine, acetylcysteine, thioglycerol, or any combination thereof) to drug is about 7:10 or less (e.g., about 1:2 or less, about 7:20 or less, about 3:10 or less, or about 1:5 or less). In some embodiments, the ratio of antioxidant to drug is about 1:20 or more (e.g., up to an upper limit described above), or about 1:10 or more, about 1:7 or more, about 1:5 or more, or the like. In certain embodiments, the weight ratio of antioxidant to drug is about 1:20 to about 7:10 (e.g., about 1:10 to about 7:10, or about 1:10 to about 5:10). In specific embodiments, the weight ratio of antioxidant-to-epinephrine is about 2:10 to about 4:10 (e.g., about 3:10).

[0108] In certain embodiments, antioxidants are provided in the composition in an amount as described herein, such as about 0.05 mg/mL to less than 1 mg/mL, about 0.05 mg/mL to about 0.7 mg/mL, about 0.05 to about 0.5 mg/mL, about 0.05 mg/mL to about 0.35 mg/mL, about 0.05 mg/mL to about 0.3 mg/mL, about 0.1 mg/mL to less than 1 mg/mL, about 0.1 mg/mL to about 0.7 mg/mL, about 0.1 mg/mL to about 0.5 mg/mL, about 0.1 mg/mL to about 0.35 mg/mL, or about 0.1 mg/mL to about 0.3 mg/mL.

[0109] In some instances, pH maintenance is an important contributor to the rate of release of active from a complexing agent (e.g., as relating the K value discussed herein). In certain embodiments, a buffering agent is utilized, such as to maintain the pH within the target range. In some embodiments, such as wherein a complexing agent is omitted, the buffering agent is optionally omitted. The buffering agent formulated into a composition herein can be any suitable agent. In specific embodiments, the buffering agent is or comprises, by way of non-limiting example, acetic acid, acetate (e.g., formulated with sodium acetate, sodium acetate anhydrous), ascorbic acid, ascorbate (e.g., formulated with sodium ascorbate), benzoic acid, benzyl benzoic acid, benzyl benzoate, benzoate (e.g., formulated with sodium benzoate), benzenesulfonic acid, citric acid (e.g., formulated with citric acid (anhydrous), citric acid (monohydrate)), citrate (e.g., formulated with sodium citrate, disodium citrate (sesquihydrate), disodium hydrogen citrate, trisodium citrate (anhydrous), or trisodium citrate (dihydrate)), maleic acid, methanesulfonic acid, phosphoric acid, metaphosphoric acid, phosphate (e.g., formulated with potassium phosphate (monobasic), potassium phosphate (dibasic), sodium phosphate, sodium phosphate (dibasic), sodium phosphate (dibasic, anhydrous), sodium phosphate (dibasic, heptahydrate), sodium phosphate (monobasic), sodium phosphate (monobasic anhydrous), sodium phosphate (monobasic, monohydrate), or sodium phosphate (monobasic, dihydrate)), succinic acid, succinate (e.g., formulated with sodium succinate, or sodium succinate hexahydrate), tartaric acid, tartarate (e.g., formulated with sodium tartarate), and/or a combination thereof. It is to be understood that a composition provided herein and formulated with such a composition may comprise the buffering agent as is, or as a conjugate acid or base thereof (e.g., a composition formulated with citric acid may comprise citric acid and/or citrate at varying concentrations depending on the pH of the composition). In certain embodiments, a composition provided herein comprises 0.001 wt. % to about 2 wt. % (e.g., about 0.001 wt. % to about 1 wt. %, about 0.001 wt. % to about 0.01 wt. %, about 0.001 wt. % to about 0.02 wt. %, about 0.001 wt. % to about 0.05 wt. %, or the like) buffering agent (e.g., based on combined weight of conjugate acid and base thereof). In specific embodiments, of the composition comprises about 0.005 wt. % to about 0.05 wt. %. In further or alternative embodiments, the weight ratio of buffering agent (e.g., citric acid/citrate) to drug is about 1:20 to about 1:2, such as about 1:20 to about 1:5, about 1:10 to about 1:2, about 1:10 to about 1:5, or the like.

[0110] In some embodiments, a composition provided herein comprises a chelating agent, such as to further reduce epinephrine degradation, e.g., due to the presence of any trace metallic catalyst. Any suitable chelating agent is optionally utilized. In specific embodiments, the chelating agent is, by way of non-limiting example, edetate. In various embodiments, edetate is ethylenediaminetetraacetic acid, or an anion (e.g., −1, −2, −3, or −4 anion), solvate, or salt thereof, such as a compound represented by the formula: (ROOCCH.sub.2).sub.2NCH.sub.2CH.sub.2N(CH.sub.2COOR).sub.2, wherein each R is independently H or a negative charge (which negative charge may be in association with a cationic species, such as Na.sup.+, Ca.sup.2+, H.sub.3O.sup.+, or the like). In various embodiments herein, compositions comprising edetate are formulating using ethylenediaminetetraacetic acid or a pharmaceutically acceptable salt thereof, such as, by way of non-limiting example, calcium disodium, edetate disodium, edetate disodium anhydrous, edetate sodium, edetate disodium dehydrate, edetate tetrasodium, and/or a combination thereof. In some embodiments, chelating agent (e.g., edetate) is utilized in an amount of about 0.001 wt % to about 1 wt. %. In specific embodiments, edetate disodium is utilized to formulation a composition herein. In further or alternative embodiments, chelating agent (e.g., edetate, such as formulated with edetate disodium) is utilized in an amount of about 0.001 wt. % to about 0.05 wt. % (e.g., about 0.005 wt. % to about 0.05 wt. %, about 0.005 wt. % to about 0.01 wt. %, or the like). In some embodiments, the weight ratio of chelating agent (e.g. edetate—e.g., using edetate disodium in formulating) to epinephrine is about 1:20 to about 1:2.

[0111] In some embodiments, water suitable for injection (WFI) is utilized as an aqueous diluent. In some instances, the pH of WFI is adjusted to effectively enhance the physicochemical stability of epinephrine complex formulation (e.g., using hydrochloric acid and/or sodium hydroxide) to a specific range of pH 2-5 (e.g., about pH 2.5, about pH 3.5, about pH 2.5 to about pH 3.5, or the like).

[0112] In some embodiments, a tonicity modifier is utilized to adjust the solution osmolality within a body physiological range. Any suitable tonicity modifier is optionally utilized, such as, by way of non-limiting example, sodium chloride and/or dextrose or a combination thereof. In specific embodiments, sodium chloride is utilized (dissolved/disassociated sodium chloride being present in a composition herein). In specific embodiments, a tonicity modifier is used to provide the solution osmolality within a range of about 200-400 mOsm/kg.

[0113] In another embodiment, epinephrine complex and non-complex formulations is used in a conjunction with an administrative device. Any suitable device is utilized. In specific embodiments, the device is, by way of non-limiting example, a pre-filled syringe or cartridge with or without the auto injector for both manual and auto injections. In some instances, such devices are calibrated and/or configured to precisely and accurately deliver effective amount of epinephrine medication.

[0114] In another embodiment, epinephrine complex and non-complex formulations can be used for treating anaphylactic shock by administrating epinephrine formulation to patients via intramuscular injection or subcutaneous injection or intravenous injection.

[0115] It is to be understood that any reference to a composition comprising an associate compound described herein (e.g., a salt or an acid) includes a composition comprising disassociated and/or solvated forms of that compound (e.g., ions of a salt and/or conjugate base of an acid).

[0116] The following non-limiting examples are provided to further explain and illustrate the invention.

EXAMPLES

[0117] Pharmaceutical formulations are prepared by mixing cyclodextrin, edetate, citric acid, cysteine, and sodium chloride into a pH 2.0 WFI prior to adding and mixing epinephrine. Adjust formulation pH to the target pH using HCl and/or NaOH solutions. Adjust the final volume using a target pH WFI. Examples 1-10 are prepared using this procedure.

Example 1

[0118]

TABLE-US-00002 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 SBEβCD 6.0 Cysteine 5.0 Citric Acid 5.0 Edetate 2.0 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 2

[0119]

TABLE-US-00003 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 SBEβCD 6.0 Cysteine 5.0 Citric Acid 5.0 Edetate 2.0 Sodium Chloride 7.8 HCl and/or NaOH (pH 3.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 3

[0120]

TABLE-US-00004 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 HPβCD 4.0 Cysteine 5.0 Citric Acid 5.0 Edetate 2.0 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 4

[0121]

TABLE-US-00005 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 HPβCD 4.0 Cysteine 5.0 Citric Acid 5.0 Edetate 2.0 Sodium Chloride 7.8 HCl and/or NaOH (pH 3.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 5

[0122]

TABLE-US-00006 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 SBEβCD 6.0 Cysteine 2.0 Citric Acid 2.0 Edetate 0.2 Sodium Chloride 7.8 HCl and/or NaOH (pH 3.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 6

[0123]

TABLE-US-00007 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 HPβCD 4.0 Cysteine 2.0 Citric Acid 2.0 Edetate 0.2 Sodium Chloride 7.8 HCl and/or NaOH (pH 3.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 7

[0124]

TABLE-US-00008 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 SBEβCD 6.0 Cysteine 1.0 Citric Acid 1.0 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 8

[0125]

TABLE-US-00009 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 HPβCD 4.0 Cysteine 1.0 Citric Acid 1.0 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 9

[0126]

TABLE-US-00010 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 SBEβCD 6.0 Cysteine 0.1 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 10

[0127]

TABLE-US-00011 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 HPβCD 4.0 Cysteine 0.1 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

[0128] The method of preparing non-complex formulations and using an antioxidant in Examples 11-15 is carried out by mixing edetate, citric acid, cysteine, and sodium chloride into a pH 2.0 WFI prior to adding and mixing epinephrine. Adjust formulation pH to the target pH using HCl and/or NaOH solutions. Adjust the final volume using a target pH WFI.

Example 11

[0129]

TABLE-US-00012 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 Cysteine 0.1 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 12

[0130]

TABLE-US-00013 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 Cysteine 0.3 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 13

[0131]

TABLE-US-00014 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 Cysteine 0.5 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 14

[0132]

TABLE-US-00015 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 Cysteine 0.7 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 15

[0133]

TABLE-US-00016 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 Cysteine 1.0 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

[0134] The method of preparing non-complex formulation and using an antioxidant in Examples 16-20 is carried out by mixing edetate, citric acid, thioglycerol, and sodium chloride into a pH 2.0 WFI prior to adding and mixing epinephrine. Adjust formulation pH to the target pH using HCl and/or NaOH solutions. Adjust the final volume using a target pH WFI.

Example 16

[0135]

TABLE-US-00017 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 Thioglycerol 0.1 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 17

[0136]

TABLE-US-00018 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 Thioglycerol 0.3 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 18

[0137]

TABLE-US-00019 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 Thioglycerol 0.5 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 19

[0138]

TABLE-US-00020 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 Thioglycerol 0.7 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 20

[0139]

TABLE-US-00021 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 Thioglycerol 1.0 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

[0140] The method of preparing non-complex formulations and using an antioxidant in Examples 21-25 is carried out by mixing edetate, citric acid, acetylcysteine, and sodium chloride into a pH 2.0 WFI prior to adding and mixing epinephrine. Adjust formulation pH to the target pH using HCl and/or NaOH solutions. Adjust the final volume using a target pH WFI.

Example 21

[0141]

TABLE-US-00022 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 Acetylcysteine 0.1 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 22

[0142]

TABLE-US-00023 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 Acetylcysteine 0.3 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 23

[0143]

TABLE-US-00024 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 Acetylcysteine 0.5 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 24

[0144]

TABLE-US-00025 Concentration Ingredient (mg/mL) Epinephrine (as free base) 1.0 Acetylcysteine 0.7 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 25

[0145]

TABLE-US-00026 Ingredient Concentration (mg/mL) Epinephrine (as free base) 1.0 Acetylcysteine 1.0 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

[0146] The method of preparing non-complex formulations and using mixed antioxidants in Examples 26-28 is carried out by mixing edetate, citric acid, antioxidants (i.e. cysteine, thioglycerol and acetylcysteine) and sodium chloride into a pH 2.0 WFI prior to adding and mixing epinephrine. Adjust formulation pH to the target pH using HCl and/or NaOH solutions. Adjust the final volume using a target pH WFI.

Example 26

[0147]

TABLE-US-00027 Ingredient Concentration (mg/mL) Epinephrine (as free base) 1.0 Cysteine 0.1 Thioglycerol 0.1 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 27

[0148]

TABLE-US-00028 Ingredient Concentration (mg/mL) Epinephrine (as free base) 1.0 Cysteine 0.1 Acetylcysteine 0.1 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 28

[0149]

TABLE-US-00029 Ingredient Concentration (mg/mL) Epinephrine (as free base) 1.0 Thioglycerol 0.1 Acetylcysteine 0.1 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s. Water for Injection (WFI) q.s.

[0150] The method of preparing non-complex pediatric formulations in Examples 29-32 is carried out by mixing edetate, citric acid, antioxidants (i.e. cysteine, thioglycerol and acetylcysteine) and sodium chloride into a pH 2.0 WFI prior to adding and mixing epinephrine. Adjust formulation pH to the target pH using HCl and/or NaOH solutions. Adjust the final volume using a target pH WFI.

Example 29

[0151]

TABLE-US-00030 Ingredient Concentration (mg/mL) Epinephrine (as free base) 0.5 Cysteine 0.1 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 30

[0152]

TABLE-US-00031 Ingredient Concentration (mg/mL) Epinephrine (as free base) 0.5 Cysteine 0.1 Thioglycerol 0.1 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 31

[0153]

TABLE-US-00032 Ingredient Concentration (mg/mL) Epinephrine (as free base) 0.5 Cysteine 0.1 Acetylcysteine 0.1 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 32

[0154]

TABLE-US-00033 Ingredient Concentration (mg/mL) Epinephrine (as free base) 0.5 Thioglycerol 0.1 Acetylcysteine 0.1 Citric Acid 0.1 Edetate 0.1 Sodium Chloride 7.8 HCl and/or NaOH (pH 2.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

Example 33

[0155] The method of preparing a typical commercial “sulfite” formulation in Examples 33 was carried out by mixing sodium chloride and sodium bisulfite into a pH 2.2 WFI prior to adding and mixing epinephrine. Adjust formulation pH to the target pH using HCl and/or NaOH solutions. Adjust the final volume using a target pH WFI.

TABLE-US-00034 Ingredient Concentration (mg/mL) Epinephrine (as free base) 1.0 Sodium Bisulfite 1.5 Sodium Chloride 8.5 HCl and/or NaOH (pH 3.5 ± 0.1) q.s. Water for Injection (WFI) q.s.

[0156] All epinephrine formulation candidates were tested for drug potency, pH and appearance of coloration and precipitation. Selected samples were also tested for drug chirality. The potency and chirality of drug were analyzed using HPLC methods. The degree of coloration was visually inspected and analytically measured their optical densities using a UV/VIS spectrophotometer at the maximum absorption wavelength (λmax) at 485 nm. Iodine solution (0.0005 N) in water was used as a reference standard to confirm the instrument read-out consistency.

[0157] Surprisingly, as illustrated in TABLES 2-4, after 1 month storage at 50° C., substantial drug degradations were observed in samples having cysteine levels of 0.1 wt. % to 0.5 wt. % or 1:1 to 5:1 weight ratio of cysteine-to-drug (compositions of Examples 1-8).

[0158] At 5:1 weight ratio of cysteine-to-drug, epinephrine in both SBEβCD and HPβCD formulations was rapidly degraded in the same fashion to be ˜67% (Examples 1 and 3) and ˜86-90% (Examples 2 and 4) at pHs 2.5 and 3.5, respectively as shown in TABLE 2. The appearances of precipitation and slight discoloration were similarly observed in both complex formulations at pH 2.5 and 3.5, respectively (TABLE 2).

TABLE-US-00035 TABLE 2 Stabilities of epinephrine complex formulations containing about 0.5 wt. % antioxidant (cysteine) (5:1 weight ratio of cysteine-to-drug) after 1 month storage at 50° C. Potency Example CD (%) pH Appearance O.D. 1 SBEβCD 66.5 2.6 Colorless & precipitation 0.0039 2 SBEβCD 86.0 3.5 Slightly light tan 0.0086 3 HPβCD 67.4 2.6 Colorless & precipitation 0.0057 4 HPβCD 89.5 3.6 Slightly light tan 0.0086 NA 0.0005N NA NA Slightly brownish 0.1290 Iodine ND = Not detected; NA = Not Applicable; O.D. = Optical density (Absorbance at λmax = 485 nm)

[0159] At 2:1 weight ratio of cysteine-to-drug (Examples 5 and 6), epinephrine degradations in both complex formulations at pH 3.5 were found to be ˜87-93% and comparable to that (˜86-90%) at 5:1 weight ratio (Examples 2 and 4) and same pH condition as shown in TABLE 3. The appearances of both formulations were “clear, colorless & no particulates”.

TABLE-US-00036 TABLE 3 Stabilities of epinephrine complex formulations containing about 0.2 wt. % antioxidant (cysteine) (2:1 weight ratio of cysteine-to-drug) after 1 month storage at 50° C. Ex- Potency ample CD (%) pH Appearance O.D. 5 SBEβCD 87.1 3.4 Clear, colorless & 0.0142 no particulates 6 HPβCD 92.9 3.5 Clear, colorless & 0.0024 no particulates NA 0.0005N NA NA Slightly brownish 0.1206 Iodine ND = Not detected; NA = Not Applicable; O.D. = Optical density (Absorbance at λmax = 485 nm)

[0160] At 1:1 weight ratio of cysteine-to-drug (Examples 7 and 8), epinephrine degradations in both complex formulations at pH 2.5 were found to be ˜85-92% with some improvements over that (˜67%) at 5:1 weight ratio (Examples 1 and 3) and same pH condition as shown in TABLE 4. The appearances of both formulations were “clear, colorless & no particulates”.

TABLE-US-00037 TABLE 4 Stabilities of epinephrine complex formulations containing about 0.1 wt. % antioxidant (cysteine) (1:1 weight ratio of cysteine-to-drug) at after 1 month storage at 50° C. Ex- Potency ample CD (%) pH Appearance O.D. 7 SBEβCD 85.3 2.5 Clear, colorless & 0.0146 no particulates 8 HPβCD 91.7 2.5 Clear, colorless & 0.0018 no particulates NA 0.0005N NA NA Slightly brownish 0.1206 Iodine ND = Not detected; NA = Not Applicable; O.D. = Optical density (Absorbance at λmax = 485 nm)

[0161] As demonstrated in FIG. 2, an example of HPLC chromatogram of related degradants were observed ˜11.2% (peak area) in an epinephrine solution containing 0.1 wt. % cysteine or 1:1 weight ratio of cysteine-to-drug at pH 2.5 (Example 15) after 1 month storage at 50° C.

[0162] Unexpectedly, at lower antioxidant (cysteine) levels (e.g., below 0.1 wt. % or lower than 1:1 weight ratio of antioxidant (cysteine)-to-drug), degradation of epinephrine actually decreased. For instance at 0.01 wt. % cysteine or 1:10 weight ratio of cysteine-to-drug, an excellent improvement of physicochemical stability of epinephrine in both complex formulations (Examples 9 and 10) were discovered to remain ˜100% drug potency after 1 month storage at 50° C. as shown in TABLE 5.

[0163] A typical commercial “sulfite” formulation (Example 33) was also studied and compared as a benchmark for physicochemical improvements of “sulfite free” formulations. After 1 month storage at 50° C., drug potency in commercial formulation rapidly degraded to be ˜74% compared to ˜100% of that in both SBEβCD and HPβCD formulations. The degradation products in the commercial formulation mainly epinephrine sulfonic acid (ESA) was found >37% compared to “not detected” levels in both formulations. The appearances of both complex formulations were observed to be “clear, colorless & no particulates” compared to a discoloration of “slightly brownish-tan” of that from the commercial one. The testing results are summarized and compared in TABLE 5.

[0164] Examples of HPLC chromatograms demonstrating novel physicochemical stability improvements in SBEβCD and HPβCD formulations with insignificant degradant levels in the present invention are illustrated in FIGS. 3 and 4, respectively.

TABLE-US-00038 TABLE 5 Stabilities of epinephrine complex formulations containing about 0.01 wt. % antioxidant (cysteine) (1:10 weight ratio of cysteine-to-drug) and a commercial formulation after 1 month storage at 50° C. Potency ESA Example CD (%) (%) pH Appearance O.D.  9 SBEβCD 100.1 ND 2.5 Clear, colorless & no 0.0059 particulates 10 HPβCD 99.5 ND 2.5 Clear, colorless & no 0.0060 particulates 33 None 74.0 >37 3.4 Slightly brownish-tan N/A (Commercial Formulation) 0.0005N None NA NA NA Slightly brownish 0.1354 Iodine ND = Not detected; NA = Not Applicable; O.D. = Optical density (Absorbance at λmax = 485 nm)

[0165] The physicochemical improvement of epinephrine was also discovered in a non-complex formulation containing low levels of cysteine (0.01 and 0.03 wt. % or 1:10 and 3; 10 weight ratio of cysteine-to-drug in Example 11 and 12, respectively) to be ˜99% drug potency compared to ˜90-97% at higher levels (0.05, 0.07 and 0.1 wt. % or 5:10, 7:10 and 1:1 weight ratio of cysteine-to-drug in Example 13, 14 and 15, respectively) after 1 month storage at 50° C. as shown in TABLE 6.

TABLE-US-00039 TABLE 6 Stabilities of non-complex epinephrine formulations at different antioxidant levels of cysteine after 1 month storage at 50° C. Potency Degradant Example Cysteine:Drug (%) (% peak area) pH Appearance O.D. 11 1:10 98.7 ND 2.5 Clear, colorless & no 0.0028 particulates 12 3:10 99.2 ND 2.5 Clear, colorless & no 0.0019 particulates 13 5:10 97.4 2.6 2.5 Clear, colorless & no 0.0025 particulates 14 7:10 95.0 5.0 2.5 Clear, colorless & no 0.0029 particulates 15 1:1  89.8 11.2  2.5 Clear, colorless & no 0.0038 particulates 0.0005N N/A NA NA NA Slightly brownish 0.1354 Iodine ND = Not detected; NA = Not Applicable; O.D. = Optical density (Absorbance at λmax = 485 nm)

[0166] The physicochemical improvement of epinephrine was also discovered in a non-complex formulation containing low levels of thioglycerol (0.0, 0.03, 0.05 and 0.07 wt. % or 1:10, 3; 10, 5:10 and 7:10 weight ratio of thioglycerol in Examples 16, 17, 18, 19 and 20, respectively) to be ˜99% drug potency compared to ˜97% at a higher level (0.1 wt. % or 1:1 weight ratio of thioglycerol in Example 20) after 1 month storage at 50° C. as shown in TABLE 7.

TABLE-US-00040 TABLE 7 Stabilities of non-complex epinephrine formulations at different antioxidant levels of thioglycerol after 1 month storage at 50° C. Potency Degradant Example Thioglycerol:Drug (%) (% peak area) pH Appearance O.D. 16 1:10 99.2 ND 2.5 Clear, colorless & no 0.0018 particulates 17 3:10 99.1 ND 2.5 Clear, colorless & no 0.0023 particulates 18 5:10 98.9 ND 2.5 Clear, colorless & no 0.0022 particulates 19 7:10 99.2 ND 2.5 Clear, colorless & no 0.0019 particulates 20 1:1  97.3 2.7 2.5 Clear, colorless & no 0.0025 particulates 0.0005N N/A NA NA NA Slightly brownish 0.1354 Iodine ND = Not detected; NA = Not Applicable; O.D. = Optical density (Absorbance at λmax = 485 nm)

[0167] The physicochemical improvement of epinephrine was also discovered in a non-complex formulation containing low levels of acetylcysteine (0.0, 0.03, 0.05 and 0.07 wt. % or 1:10, 3; 10, 5:10 and 7:10 weight ratio of acetylcysteine in Examples 21, 22, 23 and 24, respectively) to be ˜99% drug potency compared to ˜97% at a higher level (0.1 wt. % or 1:1 weight ratio of acetylcysteine in Example 25) after 1 month storage at 50° C. as shown in TABLE 8.

TABLE-US-00041 TABLE 8 Stabilities of non-complex epinephrine formulations at different antioxidant levels of acetylcysteine after 1 month storage at 50° C. Potency Degradant Example Acetylcysteine:Drug (%) (% peak area) pH Appearance O.D. 21 1:10 99.9 ND 2.5 Clear, colorless & no 0.0022 particulates 22 3:10 97.6 ND 2.5 Clear, colorless & no 0.0019 particulates 23 5:10 100.4 ND 2.5 Clear, colorless & no 0.0028 particulates 24 7:10 98.8 ND 2.5 Clear, colorless & no 0.0015 particulates 25 1:1  97.0 3.0 2.5 Clear, colorless & no 0.0023 particulates 0.0005N N/A NA NA NA Slightly brownish 0.1354 Iodine ND = Not detected; NA = Not Applicable; O.D. = Optical density (Absorbance at λmax = 485 nm)

[0168] The physicochemical improvement of epinephrine was also discovered in a non-complex formulation containing low levels of mixed antioxidants at 0.01 wt. % or 1:10 weight ratio of each antioxidant to drug. The formulations of mixed antioxidants of cysteine/acetylcysteine, cystenine/thioglycerol and thioglycerol/acetylcysteine are described Examples 26, 27 and 28, respectively. All combinations of mixed antioxidants demonstrated the drug potency to be ˜99-100% after 1 month storage at 50° C. as shown in TABLE 9.

TABLE-US-00042 TABLE 9 Stabilities of non-complex epinephrine formulations using mixed antioxidants at 1:10 ratio of antioxidant to drug or 0.01 wt. % after 1 month storage at 50° C. Potency Degradant Example Antioxidants (%) (% peak area) pH Appearance O.D. 26 Cysteine/ 99.5 ND 2.5 Clear, colorless & no 0.0022 Acetylcysteine particulates 27 Cysteine/ 99.5 ND 2.5 Clear, colorless & no 0.0019 Thioglycerol particulates 28 Thioglycerol/ 98.6 ND 2.5 Clear, colorless & no 0.0028 Acetylcysteine particulates 0.0005N N/A NA NA NA Slightly brownish 0.1354 Iodine ND = Not detected; NA = Not Applicable; O.D. = Optical density (Absorbance at λmax = 485 nm)

[0169] The pediatric formulations of epinephrine injection (1:2000) for anaphylaxis treatment were also explored to enhance their physicochemical stabilities and extend the product shelf lives. The non-complex formulations were investigated using a single antioxidant in Example 29 or mixed antioxidants in Examples 30-32. The physicochemical stability improvements were discover in all formulations with the drug potency greater than 99% as shown in Table 10.

TABLE-US-00043 TABLE 10 Stabilities of non-complex pediatric epinephrine formulations (1:2000) using single or mixed antioxidants at 1:10 ratio of antioxidant to drug or 0.01 wt. % after 1 month storage at 50° C. Potency Degradant Example Antioxidant(s) (%) (% peak area) pH Appearance O.D. 29 Cysteine 100.0 ND 2.5 Clear, colorless & no 0.0020 particulates 30 Cysteine/ 99.2 ND 2.5 Clear, colorless & no 0.0017 Acetylcysteine particulates 31 Cysteine/ 99.7 ND 2.5 Clear, colorless & no 0.0025 Thioglycerol particulates 32 Thioglycerol/ 99.7 ND 2.5 Clear, colorless & no 0.0013 Acetylcysteine particulates 0.0005N N/A NA NA NA Slightly brownish 0.1354 Iodine ND = Not detected; NA = Not Applicable; O.D. = Optical density (Absorbance at λmax = 485 nm)

[0170] The physicochemical stabilities of two complex formulations (Examples 9 and 10) were also evaluated and compared with a commercial product at a longer accelerated stability condition at 40° C./75% RH for six months under a guidance from ICH (The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use).

[0171] After six months under an ICH storage condition at 40° C./75% RH, epinephrine in the commercial formulation was rapidly degraded to be ˜79% compared to >95% of certain exemplified formulations in the present invention. The degradation products in the commercial formulation mainly epinephrine sulfonic acid (ESA) was found ˜32% compared to “not detected” levels in both formulations of the present invention. The testing results are summarized and presented in TABLE 11.

TABLE-US-00044 TABLE 11 Physicochemical stabilities of epinephrine complex formulations containing 0.01 wt. % antioxidant (cysteine) (1:10 weight ratio of cysteine-to-drug) and a typical commercial “sulfite” formulation after 6 month storage at 40° C./75% RH Potency ESA Example CD (%) (%) pH Appearance 9 SBEβCD >95 ND 2.6 Clear, colorless & no particulates 10 HPβCD >95 ND 2.6 Clear, colorless & no particulates 33 None 79.1 31.8 3.4 Clear, colorless & (Commercial no particulates Formulation) ND = Not detected

[0172] After twelve (12) months under an ICH storage condition at 25° C./60% RH, epinephrine in all commercial formulations including EpiPen, Adrenaclick and Auvi-Q were similarly degraded to be ˜91-93% from their initial values at 110-112% overages compared to ˜100% from that at 100% target of certain exemplified formulations in the present invention. The degradation products in the commercial formulations mainly epinephrine sulfonic acid (ESA) was found ˜9-11% compared to “not detected” levels in both formulations of the present invention. The testing results are summarized and presented in TABLE 8.

TABLE-US-00045 TABLE 8 Physicochemical stabilities of epinephrine complex formulations containing about 0.01 wt. % antioxidant (cysteine) (1:10 weight ratio of cysteine-to-drug) and the other commercial products after 12 month storage at 25° C./60% RH Potency ESA Example CD (%) (%) pH Appearance 9 SBEβCD ~100 ND 2.5 Clear, colorless & no particulates 10 HPβCD ~100 ND 2.5 Clear, colorless & no particulates EpiPen None ~91-93 ~9-11 2.5-4.5 Clear, colorless & Adrenaclick no particulates Auvi-Q ND = Not detected

[0173] In addition, after 3.5 months under ICH storage condition at 40° C./75% RH, the chirality of epinephrine racemization was also found <3% d-epinephrine in both complex formulations (Examples 9 & 10) as shown in TABLE 9. Examples of HPLC chromatograms demonstrating drug racemization in both SBEβCD and HPβCD formulations are shown in FIGS. 8 and 9, respectively.

TABLE-US-00046 TABLE 9 Chirality of epinephrine complex formulations at pH 2.5 after 3.5 month storage at 40° C./75% RH d-Epinephrine (%) Example CD Initial 3.5 Months Appearance 9 SBEβCD 1.4 2.9 Clear, colorless & no particulates 10 HPβCD 1.4 1.7 Clear, colorless & no particulates

Example 34

[0174] Epinephrine formulations as described herein are indicated in the treatment (e.g., emergency treatment) of allergic reactions (e.g., Type I) including, for example, anaphylaxis to stinging insects (e.g., order Hymenoptera, which include bees, wasps, hornets, yellow jackets and fire ants) and biting insects (e.g., triatoma, mosquitoes), allergen immunotherapy, foods, drugs, diagnostic testing substances (e.g., radiocontrast media) and other allergens, as well as idiopathic anaphylaxis or exercise-induced anaphylaxis. Epinephrine formulations in the present invention are intended for immediate administration in patients who are determined to be at increased risk for anaphylaxis, including individuals with a history of anaphylactic reactions.

[0175] Anaphylactic reactions may occur within minutes after exposure and consist of flushing, apprehension, syncope, tachycardia, thready or unobtainable pulse associated with a fall in blood pressure, convulsions, vomiting, diarrhea and abdominal cramps, involuntary voiding, wheezing, dyspnea due to laryngeal spasm, pruritus, rashes, urticaria or angioedema. Epinephrine formulations in the present invention are intended for immediate administration as emergency supportive therapy only and are not a substitute for immediate medical care.

[0176] Selection of the appropriate dosage strength of the epinephrine formulations (e.g., a formulation of any one of Examples 9-31) is determined according to patient body weight. Patients greater than or equal to 30 kg (approximately 66 pounds or more) are required 0.3 mg dose or 0.3 mL epinephrine formulation (1:1000). Patients of 15 to 30 kg (33 pounds to 66 pounds) are required 0.15 mg dose or 0.15 mL epinephrine formulation (1:1000) or alternatively 0.3 mL epinephrine formulation (1:2000). The epinephrine formulation is intramuscularly or subcutaneously injected into the anterolateral aspect of the thigh, through clothing if necessary.

[0177] The prescriber should carefully assess each patient to determine the most appropriate dose of epinephrine, recognizing the life-threatening nature of the reactions for which this drug is indicated. With severe persistent anaphylaxis, repeat injections may be necessary. More than two sequential doses of epinephrine should only be administered under direct medical supervision.

[0178] Epinephrine formulation should only be injected into the anterolateral aspect of the thigh. Do not inject intravenously. Rapidly acting vasodilators can counteract the marked pressor effects of epinephrine if there is such inadvertent administration. Do not inject into digits, hands or feet. Since epinephrine is a strong vasoconstrictor when injected into the digits, hands, or feet, treatment should be directed at vasodilatation if there is such an accidental injection to these areas. Do not inject into buttock. If there is an accidental injection into these areas, advise the patient to inform the healthcare provider of the accidental injection when he/she goes to the nearest emergency room for further treatment of anaphylaxis.

[0179] Epinephrine should be administered with caution to patients who have heart disease, including patients with cardiac arrhythmias, coronary artery or organic heart disease, or hypertension. In such patients, or in patients who are on drugs that may sensitize the heart to arrhythmias, epinephrine may precipitate or aggravate angina pectoris as well as produce ventricular arrhythmias. Epinephrine should be administered with caution to patients with hyperthyroidism, diabetes, elderly individuals, and pregnant women. Patients with Parkinson's disease may notice a temporary worsening of symptoms.

[0180] Unlike all commercial products currently available on the market, certain epinephrine formulations in the present invention are a “sulfite free” formulation and safe for the sulfite-sensitive patient.