Saquinavir Capsules

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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» Saquinavir Capsules contain not less than 95.0 percent and not more than 105.0 percent of saquinavir (C₃₈H₅₀N₆O₅).

Packaging and storage— Preserve in tight containers, and store at controlled room temperature.

USP Reference standards 〈11〉—

USP Saquinavir Mesylate RS

USP Saquinavir Related Compound A RS

N-tert-Butyl-decahydro-2-[2(R)-hydroxy-4-phenyl-3(S)-[[N-(2-quinolylcarbonyl)-d-asparaginyl]amino]butyl]-(4aS,8aS)-isoquinoline-3(S)-carboxamide.

C₃₈H₅₀N₆O₅ 670.84

1 Identification—

Change to read:

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

B: The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.

Dissolution 〈711〉—

Citrate buffer—

Transfer 5.82 g of anhydrous dibasic sodium phosphate and 16.7 g of citric acid monohydrate to a 1-L volumetric flask. Dissolve in and dilute with water to volume.

Medium: Citrate buffer; 900 mL.

Apparatus 2: 50 rpm.

Time: 45 minutes.

Procedure—

Determine the amount of C₃₈H₅₀N₆O₅ dissolved by employing UV absorption at the wavelength of maximum absorbance at about 240 nm on filtered portions of the solution under test, suitably diluted with Medium, in comparison with a Standard solution having a known concentration of USP Saquinavir Mesylate RS in the same Medium.

Tolerances—

Not less than 75% (Q) of the labeled amount of C₃₈H₅₀N₆O₅ is dissolved in 45 minutes.

Uniformity of dosage units 〈905〉:

Meet the requirements.

Water Determination, Method I 〈921〉:

Not more than 3.0%.

Chromatographic purity—

Triethylamine phosphate solution, Mobile phase, System suitability solution, and Chromatographic system—Proceed as directed in the Assay under Saquinavir Mesylate.

Standard solution—

Use the Standard preparation prepared as directed in the Assay under Saquinavir Mesylate.

Test solution—

Use the Assay preparation.

Procedure—

Separately inject equal volumes (about 20 μL) of the Test solution and the Standard solution into the chromatograph, record chromatograms, measure peak responses.

Calculate percentage of each impurity:

10,000 F (670.86/766.96)(C/W)(rᵢ/rₛ)

Where:

F = response factor:

• = 2 for peak at relative retention 0.32

• = 0.5 for peaks at relative retention 0.38 and 0.53

• = 1 for all other peaks

670.86 = molecular weight of saquinavir

766.96 = molecular weight of saquinavir mesylate

C = concentration (mg/mL) of USP Saquinavir Mesylate RS in Standard solution

W = weight (mg) of Capsule contents used

rᵢ = impurity peak response (Test solution)

rₛ = saquinavir peak response (Standard)

Limits:

Not more than 0.2% of any individual impurity

Not more than 1.0% total impurities

2 Assay—

Triethylamine phosphate solution, Mobile phase, System suitability solution, Standard preparation, and Chromatographic system—Proceed as directed in the Assay under Saquinavir Mesylate.

Assay preparation—

Empty and combine the contents of not fewer than 10 Capsules. Transfer a portion equivalent to about 22 mg of saquinavir, accurately weighed, to a 100-mL volumetric flask. Dissolve and dilute with Mobile phase to volume, and mix.

Procedure—

Inject equal volumes (about 20 μL) of the Standard preparation and the Assay preparation into the chromatograph. Record the chromatograms, and measure the responses for the major peaks.

Calculate the quantity, in mg, of saquinavir (C₃₈H₅₀N₆O₅) in the portion of Capsules taken by the formula:

(670.86/766.96)(100C)(rᵤ/rₛ)

in which 670.86 and 766.96 are the molecular weights of saquinavir and saquinavir mesylate, respectively; C is the concentration, in mg per mL, of USP Saquinavir Mesylate RS in the Standard preparation; and rᵤ and rₛ are the peaks obtained from the Assay preparation and the Standard preparation, respectively.