Identification of degradation products of saquinavir mesylate by LC-MS: Molecular docking and in silico ADME prediction studies

Kiran Gangarapu,Vasudha Bakshi,Thumma Gouthami,Mulagada Monja,Julakanti Venu

doi:10.3390/ecmc-4-05627

Kiran Gangarapu, Vasudha Bakshi + Show 3 more

Open Access

https://doi.org/10.3390/ecmc-4-05627

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Abstract

Saquinavir mesylate (SQM) is subjected to forced degradation under conditions of hydrolysis, oxidation, dry heat, photolysis as recommended by International Conference on Harmonization guideline Q1A (R2). In total, (I-V) degradation products (DPs) were formed in acidic hydrolytic, alkaline hydrolytic and oxidative conditions. Successful separation of SQM and its DPs was achieved on C18(4.6mm×75mm) 3.5µg column at ambient temperature (30˚C) with mobile phase A (10mM ammonium acetate in water), B100% acetonitrile at 2.0ml/min flow rate in the gradient mode. The injection volume was fixed at 20µl and detection wavelength at 238nm. The HPLC method was found to be linear, accurate, precise, sensitive, specific, rugged, and robust for quantification of SQM as well as degradation products. The major degradation products (DP-1) formed under hydrolytic acid conditions were identified and characterized by LC-MS/MS. Further, DP-1 were isolated through column chromatography and analyzed by 1H NMR. In silico molecular docking studies on HIV protease (PDB: 4qgi) for DPs and SQM as well as prediction of toxicity and ADME properties were performed.

Highlights

Saquinavir mesylate is used to treat HIV infection by selectively binding to the protease enzymes and preventing its replication(Deeks, Smith, Holodniy, & Kahn, 1997)
A few HPLC methods reported for simultaneous estimation and identification of degraded products of Saquinavir mesylate (SQM) by LC-MS/MS. (Thummar et al, 2017)
Gananadhamu et al, has reported on forced degradation products of SQM by UPLC-ESI-Q-TOF-MS/MS where major degradation is achieved with acid hydrolysis(Mohit et al, 2017)

Summary

Graphical Abstract

Abstract: Saquinavir mesylate (SQM) is subjected to forced degradation under conditions of hydrolysis, oxidation, dry heat, photolysis as recommended by International conference on Harmonization guideline Q1A (R2). (I-V) degradation products (DPs) were formed in acidic hydrolytic, alkaline hydrolytic and oxidative conditions. Successful separation of SQM and its DPs was achieved on C18(4.6mm×75mm) 3.5μg column at ambient temperature (30 ̊C) with mobile phase A (10mM ammonium acetate in water), B100% acetonitrile at 2.0ml/min flow rate in the gradient mode. The HPLC method was found to be linear, accurate, precise, sensitive, specific, rugged, and robust for quantification of SQM as well as degradation products. The major degradation products (DP-1) formed in hydrolytic acid conditions was identified and characterized by LC-MS/MS and proposed the fragmentation patterns by comparing with SQM.

Introduction

Method validation

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