Amobarbital Sodium for Injection

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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1 DEFINITION

Amobarbital Sodium for Injection is Amobarbital Sodium suitable for parenteral use. It contains NLT 98.5% and NMT 100.5% of the labeledamount of amobarbital sodium (C₁₁H₁₇N2NaO₃), calculated on the dried basis.

2 IDENTIFICATION

Change to read:

A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197K (CN 1-May-2020)

Sample: Residue obtained in the Assay

Acceptance criteria: Meets the requirements

B. Identification Tests - General, Sodium 〈191〉

Sample: Nominally 200 mg of amobarbital sodium from Amobarbital Sodium for Injection

Analysis: Ignite the Sample.

Acceptance criteria: The residue effervesces with acid and meets the requirements of the tests.

3 ASSAY

Procedure

Sample solution: Transfer nominally 500 mg of amobarbital sodium from Amobarbital Sodium for Injection to a suitable separator, and dissolve in 15 mL of water. Add 2 mL of hydrochloric acid, and shake. Completely extract the amobarbital with 25-mL portions of chloroform. Combine the chloroform extractions, and pass through a glass filter funnel into a tared beaker. Wash the separator and the filter with several small portions of chloroform. Use the combined chloroform extractions and the washings.

Test for completeness of extraction: Extract the remaining solution in the separator with an additional 10-mL portion of chloroform, and evaporate the solvent; NMT 0.5 mg of residue remains.

Analysis: Evaporate the Sample solution on a steam bath with the aid of a current of air. Dry the residue at 105° for 30 min, cool, and weigh.

Calculate the percentage of the labeled amount of amobarbital sodium (C₁₁H₁₇N2NaO₃) in the portion of Amobarbital Sodium for Injection taken:

Result = (W_R/W_S) × (M_r1/M_r2) × 100

W_R = weight of the residue from the Analysis (mg)

W_S = nominal weight of amobarbital sodium in the Sample solution (mg)

M_r1 = molecular weight of amobarbital sodium, 248.25

M_r2 = molecular weight of amobarbital, 226.27

Acceptance criteria: 98.5%–100.5% on the dried basis

4 PERFORMANCE TESTS

Uniformity of Dosage Units 〈905〉: Meets the requirements

5 SPECIFIC TESTS

Injections and Implanted Drug Products 〈1〉, Specific Tests, Completeness and clarity of solutions: At the time of use, it meets the requirements.

Completeness of Solution 〈641〉

Sample solution: 1 g of amobarbital sodium from Amobarbital Sodium for Injection in 10 mL of carbon dioxide-free water

Acceptance criteria: After 1 min, the solution is clear and free from undissolved solid.

Loss on Drying 〈731〉

Sample: 1 g

Analysis: Dry the Sample at 105° for 4 h.

Acceptance criteria: NMT 1.0%

pH 〈791〉

Sample solution: Nominally 100 mg/mL of amobarbital sodium from Amobarbital Sodium for Injection in carbon dioxide-free water

Acceptance criteria: NMT 11.0

Sterility Tests 〈71〉: Meets the requirements

Bacterial Endotoxins Test 〈85〉: It contains NMT 0.4 USP Endotoxin Units/mg of amobarbital sodium.

Other Requirements: It meets the requirements in Labeling 〈7〉, Labels and Labeling for Injectable Products.

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve as described in Packaging and Storage Requirements 〈659〉, Injection Packaging, Packaging for constitution.

USP Reference Standards 〈11〉

USP Amobarbital RS