Gonadorelin 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

Gonadorelin for Injection is a sterile mixture of Gonadorelin Hydrochloride with suitable diluents. It contains the equivalent of NLT 90.0% and NMT 115.0% of the labeled amount of gonadorelin (C₅₅H₇₅N₁₇O₁₃).

2 IDENTIFICATION

A.

Buffer solution, Mobile phase, Standard solution 2, Sample solution, Chromatographic system, and System suitability: Proceed as directed in the Assay.

Identity sample solution: Mix equal volumes of Standard solution 2 and the Sample solution.

Analysis

Samples: Standard solution 2, Sample solution, and Identity sample solution

Acceptance criteria: The retention time of the major peak of the Sample solution corresponds to that of Standard solution 2, and the major peak of the Identity sample solution elutes as a single peak.

3 ASSAY

Procedure

[Note—Perform all manipulations involving the weighing of the gonadorelin hydrochloride sample and the Reference Standard in a low-humidity glove box.]

Buffer solution: 6.8 mg/mL of monobasic potassium phosphate in water. Adjust with 1 N potassium hydroxide to a pH of 6.5.

Mobile phase: Acetonitrile and Buffer solution (18:82)

Standard solution 1: 80 µg/mL of USP Gonadorelin Hydrochloride RS in Mobile phase

Standard solution 2: 100 µg/mL of USP Gonadorelin Hydrochloride RS in Mobile phase

Standard solution 3: 120 µg/mL of USP Gonadorelin Hydrochloride RS in Mobile phase

[Note—The Standard solutions may be stored in a refrigerator for 2 months. Remove suitable portions and warm to room temperature before use.]

Sample solution: Separately dissolve the contents of NLT 5 vials of Gonadorelin for Injection in Mobile phase to obtain a nominal concentration of 100 µg/mL of gonadorelin. Sonicate the vials for 5 min, and allow to cool to room temperature. Combine the solutions in the vials to obtain the Sample solution.

3.1 Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 220 nm

Column: 4.6-mm × 15-cm; 5-µm packing L1

Flow rate: 1.5 mL/min

Injection volume: 20 µL

3.2 System suitability

Sample: Standard solution 1

[Note—The retention time for gonadorelin is 8–11 min.]

Suitability requirements

Tailing factor: NMT 2.5

Relative standard deviation: NMT 3.0% for gonadorelin

3.3 Analysis

Samples: Standard solutions and Sample solution

[Note—If more than ve specimens are analyzed, reinject the Standard solutions before injecting further specimens of the Sample solution.]

Plot the responses of the gonadorelin peaks versus concentration, in mg/mL, of gonadorelin in each of the Standard solutions, and determine the regression line, using the least-squares method. The coefficient of variation from the regression line is NMT 3.0%. From the graph so obtained, determine the concentration, C, of gonadorelin in the Sample solution (mg/mL).

Calculate the percentage of the labeled amount of gonadorelin (C₅₅H₇₅N₁₇O₁₃) in the portion of Gonadorelin for Injection taken: 

Result = C × (M_r1 /M_r2 ) × (V + F) × (100/L)

C = concentration of gonadorelin in the Sample solution as obtained from the regression line (µg/mL)

M_r1 = molecular weight of gonadorelin, 1182.3

M_r2 = molecular weight of gonadorelin hydrochloride, 1255.2

V = volume of Mobile phase used to prepare the Sample solution (mL)

F = correction factor for the volume created by the dissolved sample, 0.06 mL

L = label claim (µg)

Acceptance criteria: 90.0%–115.0%

4 SPECIFIC TESTS

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

pH 〈791〉: 4.0–8.0, in a solution constituted as directed in the labeling

Sterility Tests 〈71〉: Meets the requirements

Bacterial Endotoxins Test 〈85〉: It contains NMT 70 USP Endotoxin Units/mg.

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

5 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight, well-sealed containers.

USP Reference Standards 〈11〉

USP Gonadorelin Hydrochloride RS