Entecavir Tablets

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

Entecavir Tablets contain NLT 90.0% and NMT 105.0% of the labeled amount of entecavir (C₁₂H₁₅N₅O₃).

2 IDENTIFICATION

A. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

PROCEDURE

Solution A: Acetonitrile, trifluoroacetic acid, and water (1:0.1:99)

Solution B: Acetonitrile, trifluoroacetic acid, and water (30:0.1:70)

Mobile phase: See Table 1. [Nort-The gradient elution times are established on an HPLC system with a dwell volume of approximately 1.1 mL

Diluent: 0.01 N hydrochloric acid

Standard stock solution: 0.2 mg/mL of USP Entecavir Monohydrate RS prepared as follows. Transfer a suitable quantity of USP Entecavir Monohydrate RS into an appropriate volumetric flask. Dissolve in NMT 20% of the flask volume of methanol, and sonicate if necessary. Dilute with Diluent to volume.

Standard solution: 10 μg/mL of USP Entecavir Monohydrate RS in Diluent from Standard stock solution

Sample solution: Nominally 10 μg/mL of entecavir prepared as follows. Transfer NLT 5 Tablets to an appropriate volumetric flask. Add 80% of the flask volume of Diluent, and sonicate for 30 min. Cool to room temperature. Dilute with Diluent to volume, and centrifuge for 10 min. Pass the supernatant through a suitable filter, and use the filtrate for analysis.

Chromatographic system

(See Chromatography (621) System Suitability)

Mode: LC

Detector: UV 254 nm

Column: 4.6-mm × 10-cm; 3-μm packing L1

Temperatures

Column: 30°

Autosampler: 4°

Flow rate: 1 mL/min

Injection volume: 75 με

System suitability

Sample: Standard solution

Sultability requiremento

Tailing factor: 0.8–1.5

Relative standard deviation: NMT 2.0%

Analysis

Samples: Standhard solution and Sample solution

Calculate the percentage of the labeled amount of entecavir (C₁₂H₁₅N₅O₃) in the portion of Tablets taken

Result = (r_U/(r_S) × (C_S /C_U) x 100

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution

C_S = concentration of USP Entecavir Monohydrate RS in the Standard solution (mg/ml)

C_U = concentration of Entecavir in the Sample solution (mg/mL)

Acceptance criteria: 90.0%-105.0%

4 PERFORMANCE TESTS

Dissolution (711)

Test 1

Medium: Semulatest intestinal fhed TS without enzyme 1000 mL

Apparatus 2:50 rpm

Time: 30 min

Mobile phase: Acetonitrile and water (8:22)

Standard stock solution: 0.1 mg/ml of USP Ergocal Monobydrate RS in Medium prepared as follows. Transher a suitable amount of USE Entecavir Monohydrate RS to a suitable flask and add Medium to about 66% of the flask volume. Sonicate until dissolved. Dilute with Medium to volume

Standard solution: Dilute an appropriate volume from the Standard stock solution in Medium to obtain a similar concentration as the Sample

solution. Prepare fresh on the day of use

Sample solution: Pass the solution through a suttsible filter of 45-um pore size

Chromatographic system

Mode: LC

Detector: UV 254m

Column: 4.6-mm × 15-cm; 3-μm packing L1

Flow rate: 1 m/min

Injection volume: 100 μL

Rus time: NLT 2 times the retention time of entecavir

System suitability

Sample: Standard solution

Sultability requirements

Tailing factor: 0.8-1.5

Relative standard deviation: NMT 2.0%

Analysis

Samples: Standard andion and Sample solution

Calculate the percentage of the labeled amount of entecavir (C₁₂H₁₅N₅O₃) is dissolved

Result = (r_U/(r_S) × C_S x (1/L) x 100

r_U = peak response of entecavir from the Sample solution

r_S = peak response of entecavir from the Standard solution

C_S = concentration of USP Entecavir Monohydrate RS in the Standard solution (mg/ml)

V = volume of Medium, 1000ml

L = label claim (mg/Tablet)

Tolerances: NLT 80% (0) of the labeled amount of entecavir (C₁₂H₁₅N₅O₃) is dissolved

Test 2: if the product complies with this test, the labeling indicates that the product meets USP Dissolution Test 2

Medium: pH 6.8 phosphate buffer: 1000

Apparatus 2:50 rpm

Time: 15 min

Buffer: 2 git of immanium acetate in water. Adjust with glacial acetic acid to a of 50. Pass through a suitable Siter

Mobile phase: Acetonitrile and Buffer (7:93)

Standard stock solution: 0.6 mg/ml of USP Emoca Mondbysirate RS in methanol prepared as folkows. Transfer a suitable amount of 15 Entecavir Monohydrate to a suitable volumetric flask and add methanol to about 20% of the flask volume. Sonicate until dissolved. Dilute with meshanul to vulume

Standard andution: Dilute an appropriate volume from the Standard stock solution in Medium to obtain a similar concentration as the Sample solution.

Sample solution Pass the solution through a suitable fitter of it 0.45-μm pore size

Chromatographic system

Mode: LC

Detector: UV-254m

Column: 4.6-mm × 25-cm; 5-μm packing L1

Column temperature: 40°

Flow rate: 1 mL/min

Injection volume: 100 μL

Run time: NLT 2 times the retention time of entecavir

Dystem suitability

Sample: Standard solution

Sultability requirements

Talling factor: NMT 2.0

Relative standard deviation: MT 2.0%

Analysis

Samples: Standard solution and Sample solutton

Calculate the percentage of the labeled amount of entecavie (C₁₂H₁₅N₅O₃) dissolved:

Result = (r_U/(r_S) × C_S x (1/L) x 100

r_U = peak response of entecavir from the Sample solution

r_S = peak response of entecavir from the Standard solution

C_S = concentration of USP Entecavir Monohydrate RS in the Standard solution (mg/ml)

V = volume of Medium, 1000ml

L = label claim (mg/Tablet)

Tolerances: NLT 30% (0) of the labeled amount of entecave (C₁₂H₁₅N₅O₃) is dissolved:

Uniformity of Dosage Units (905): Meet the requirements

5 IMPURITIES

Solution A, Solution B, Mobile phase, Diluent, Standard stock solution, Standard solution, Sample solution, Chromatographie system, and

System suitability: Proceed as directed in the Assay

Analysis

Sample: Sample sulution

Calculate the percentage of each impurity in the portion of Tablets taken

Result = (r_U/(r_S) x 100

r_U =  peak response of each individual impurity from the Sample solution

r_S =  sum of all the pak responses from the Sample solution

Acceptance criteria: Disregard any peak less than 0.10%

Individual impurities: NMT 0.5%

Total impurities: NMT 2.0%

SPECIFIC TESTS

Microbial Enumeration Tests (61) andTests for Specified Microorganisms (62): The total aerobic microbial count is NMT 10³ cfu/g. The total

yeasts and molds count is NMT 10² cfu/g. It meets the quints of the texts for absence of Eacherichia col

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers. Store at controlled room temperature.

Labeling: When more than one Dissolution test is given, the labeling states the Dissolution test used only if Test 1 is not used.