Lyophilized compositions of phenobarbital sodium salt
A composition of, method for producing, and use of an amorphous lyophilized Phenobarbital Sodium having high purity are presented. The amorphous lyophilized Phenobarbital Sodium is storage-stable being essentially void of impurities (e.g., phenyl ethylacetylurea (PEAU), 2-ethyl-2-phenylmalonamide (2EPMM), and/or alpha-phenylbutyrylguanidine (PBG)) upon reconstitution in water.
1 . A pharmaceutical product, comprising:
a container enclosing sterile storage stable lyophilized amorphous phenobarbital;
wherein the lyophilized phenobarbital is storage stable such that, upon storage at 25° C. and 60% relative humidity for 3 months and reconstitution with water to a concentration of 65 mg/mL, less than 0.05% of degradation products from the phenobarbital are detectable in the reconstituted solution;
wherein the degradation products are selected form the group consisting of 2-ethyl-2-phenylmalonamide (2EPMM), alpha-phenylbutyrylguanidine (PBG), and phenylethylacetylurea (PEAU); and
wherein the lyophilized phenobarbital is stored under vacuum in the container.
2 . The product of claim 1 , wherein no more than 0.05% total degradation products, including 2EPMM, PBG, and PEAU, are detectable in the reconstituted solution.
3 . The product of claim 1 , wherein the lyophilized amorphous phenobarbital contains no more than 1.8% water.
4 . The product of claim 1 , wherein the lyophilized amorphous phenobarbital contains no more than 1.5% water.
5 . The product of claim 1 , wherein at least 90% of total lyophilized phenobarbital is amorphous phenobarbital.
6 . The product of claim 1 , wherein the lyophilized amorphous phenobarbital is storage stable such that, upon storage at 25° C. and 60% relative humidity for 6 months and reconstitution with water, less than 0.05% of degradation products from the phenobarbital are detectable in the reconstituted solution.
7 . The product of claim 6 , wherein no more than 0.05% total degradation products, including 2EPMM, PBG, and PEAU, are detectable in the reconstituted solution.
8 . The product of claim 1 , wherein the container contains 65 mg of the sterile storage stable lyophilized amorphous phenobarbital.
9 . The product of claim 1 , wherein the container contains 130 mg of the sterile storage stable lyophilized amorphous phenobarbital.
10 . The product of claim 1 , wherein the container contains 65-200 mg of the sterile storage stable lyophilized amorphous phenobarbital.
11 . The product of claim 1 , wherein the lyophilized amorphous phenobarbital is storage stable such that, upon storage at 40° C. and 75% relative humidity for 3 months and reconstitution with water, less than 0.05% of degradation products from the phenobarbital are detectable in the reconstituted solution.
12 . The product of claim 11 , wherein no more than 0.1% total degradation products, including 2EPMM, PBG, and PEAU, are detectable in the reconstituted solution.
13 . The product of claim 1 , wherein the lyophilized amorphous phenobarbital is storage stable such that, upon storage at 40° C. and 75% relative humidity for 6 months and reconstitution with water, less than 0.05% of degradation products from the phenobarbital are detectable in the reconstituted solution.
14 . A method of preparing a phenobarbital solution in an aqueous carrier, comprising:
reconstituting the pharmaceutical product of claim 1 in the container in an aqueous carrier to produce a clear colorless solution comprising the phenobarbital;
wherein the clear colorless solution comprises, upon reconstitution to a concentration of 65 mg/mL, initial quantities of degradation products from the phenobarbital in an amount of less than 0.05%; and
wherein the degradation products are selected form the group consisting of 2-ethyl-2-phenylmalonamide (2EPMM), alpha-phenylbutyrylguanidine (PBG), and phenylethylacetylurea (PEAU).
15 . The method of claim 14 , wherein the clear colorless solution comprises, upon reconstitution, initial quantities of total degradation products, including 2EPMM, PBG, and PEAU, in an amount of no more than 0.05%.
16 . The method of claim 14 , wherein the aqueous carrier is water for injection, a 0.9% saline solution, or a 5% dextrose solution.
17 . The method of claim 14 , wherein the clear colorless solution comprises the phenobarbital at a concentration of 20 mg/mL.
18 . The method of claim 14 , wherein the clear colorless solution contains, upon storage for 20 hours at 25° C. and 60% relative humidity, less than 0.05% of degradation products from the phenobarbital.
19 . The method of claim 18 , wherein the clear colorless solution contains, upon storage for 20 hours at 25° C. and 60% relative humidity, no more than 0.3% total degradation products, including 2EPMM, PBG, and PEAU.
20 . The method of claim 16 , wherein the clear colorless solution has, upon reconstitution, an initial pH of between 9.5 and 9.9.