Abacavir 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

Abacavir Tablets contain Abacavir Sulfate equivalent to NLT 90.0% and NMT 110.0% of the labeled amount of abacavir (C₁₄H₁₈N₆O).

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

3.1 PROCEDURE

Diluent: 1.0 mL of phosphoric acid in 1 L of water

Solution A: Trifluoroacetic acid and water (0.05:99.95)

Solution B: Methanol and water (85:15)

Mobile phase: See Table 1.

Table 1

System suitability solution: 0.2 mg/mL of USP Abacavir System Suitability Mixture RS in Diluent

Standard solution: 0.21 mg/mL of abacavir sulfate in Diluent (equivalent to 0.18 mg/mL of abacavir), from USP Abacavir Sulfate RS

Sample stock solution: Transfer the equivalent to 1500 mg of abacavir, from a portion of Tablets, into a 250-mL volumetric flask. Add 150 mL of Diluent. Shake mechanically for 45 min. Dilute with Diluent to volume. Pass a portion through a suitable filter of 0.45-µm or finer pore size. Discard the first 3 mL of the filtrate.

Sample solution: 0.18 mg/mL of abacavir in Diluent using the filtrate obtained in the Sample stock solution

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 254 nm

Column: 3.9-mm x 15-cm; packing L1

Flow rate: 0.8 mL/min

Injection volume: 10 µL

System suitability

Samples: System suitability solution and Standard solution

Suitability requirements

Resolution: NLT 1.5 between abacavir and trans-abacavir, System suitability solution

Relative standard deviation: NMT 2.0%, Standard solution

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of abacavir (C₁₄H₁₈N₆O) in the portion of Tablets taken:

Result = (r_U/r_S) x (C_S/C_U) × (M_r1/M_r2) × 100

r_U = peak response of abacavir from the Sample solution

r_S = peak response of abacavir from the Standard solution S

C_S = concentration of abacavir sulfate in the Standard solution (mg/mL)

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

M_r1 = molecular weight of abacavir multiplied by 2, 572.66

M_r2 = molecular weight of abacavir sulfate, 670.74

Acceptance criteria: 90.0%-110.0%

4 PERFORMANCE TESTS

4.1 DISSOLUTION (711).

Medium: 0.1 N hydrochloric acid; 900 mL

Apparatus 2: 75 rpm

Time: 15 min

Standard solution: 0.39 mg/mL of USP Abacavir Sulfate RS in Medium

Sample solution: Pass a portion of the solution under test through a suitable filter of 0.45-µm pore size.

Instrumental conditions

Mode: UV

Analytical wavelength: 254 nm

Blank: Medium

Calculate the percentage of the labeled amount of abacavir (C₁₄H₁₈N₆O) dissolved:

Result = (A_U/A_S) × (CS/L) × (M_r1/M_r2) x V x 100

A_U = absorbance of the Sample solution

A_S = absorbance of the Standard solution

C_S = concentration of the Standard solution (mg/mL)

L = label claim (mg/Tablet)

M_r1 = molecular weight of abacavir multiplied by 2, 572.66

M_r2 = molecular weight of abacavir sulfate, 670.74

V = volume of Medium, 900 mL

Tolerances: NLT 80% (Q) of the labeled amount of abacavir (C₁₄H₁₈N₆O) is dissolved.

4.2 UNIFORMITY OF DOSAGE UNITS (905): Meet the requirements

5 IMPURITIES

5.1 ORGANIC IMPURITIES

Diluent, Solution A, Solution B, Mobile phase, System suitability solution, Standard solution, Sample solution, and Chromatographic

system: Proceed as directed in the Assay.

Analysis

[NOTE-Record the chromatograms for 2.5 times the retention time of abacavir.]

Samples: Standard solution and Sample solution

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

Result = (r_U/r_S) x (C_S/C_U) × (1/F) x (M_r1/M_r2) × 100

r_U = peak response of each impurity from the Sample solution

r_S = peak response of abacavir from the Standard solution s

C_S = concentration of USP Abacavir Sulfate RS in the Standard solution (mg/mL)

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

F = relative response factor for each impurity (see Table 2)

M_r1 = molecular weight of abacavir multiplied by 2, 572.66

M_r2 = molecular weight of abacavir sulfate, 670.74

Acceptance criteria: See Table 2.

Table 2

a N⁶-Cyclopropyl-9H-purine-2,6-diamine.

b [(1S,4R)-4-(2,6-Diamino-9H-purin-9-yl)-cyclopent-2-enyl]methanol.

c {(1R,4R)-4-[2-Amino-6-(cyclopropylamino)-9H-purin-9-yl]-cyclopent-2-enyl}methanol.

d Process impurity monitored in the drug substance and not included in the total impurities.

e N⁶-Cyclopropyl-9-{(1R,4S)-4-[(2,5-diamino-6-chloropyrimidin-4-yloxy)methyl]cyclopent-2-enyl}-9H-purine-2,6-diamine.

6 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in well-closed containers. Store at room temperature.

USP REFERENCE STANDARDS (11).

USP Abacavir Sulfate RS

USP Abacavir System Suitability Mixture RS

A mixture of abacavir sulfate and trans-abacavir.