Targeted and Non-Targeted Identification and Characterization of the Forced Degradation Products of Glipizide Using the ACQUITY RDa Detector and UNIFI Software Workflows

Importance of the Topic

The profiling of forced degradation products is a critical component in pharmaceutical development. It provides insight into the intrinsic stability of active pharmaceutical ingredients (APIs) and supports regulatory shelf-life determinations. High-resolution mass spectrometry (HRMS) streamlines the identification of impurities generated under stress conditions, enabling faster risk assessment and formulation design without requiring extensive HRMS expertise.

Objectives and Study Overview

This study aimed to demonstrate targeted and non-targeted workflows for the characterization of glipizide forced degradation products. Acidic, basic, and oxidative stress conditions were applied to glipizide samples. Known degradant screening (targeted) and prediction-based structure generation (non-targeted) were performed using the ACQUITY RDa Detector and UNIFI software, with the goal of establishing a routine HRMS-enabled degradation profiling method.

Methodology

Sample Preparation and Stress Conditions:

• Glipizide standard (1 mg/mL) in 80:20 methanol:water.
• Chemical stresses: 99% formic acid (acidic), 50% NaOH (basic), 30% H₂O₂ (oxidative).
• Incubation at 80 °C; sampling at 0, 30, 60, 120, 180, and 240 minutes.
• Post-stress dilution 1:10 with 80:20 methanol:water prior to analysis.

LC–MS Acquisition:

• Chromatography: ACQUITY UPLC I-Class PLUS, BEH C18 column, 45 °C, 0.4 mL/min, 1 µL injection.
• Detection: Photodiode array at 254 nm and benchtop TOF mass analyzer (RDa Detector) in positive ion mode, m/z 50–2000.
• Data collection: Full scan with fragmentation (cone voltage ramping for simultaneous low/high energy spectra).

Used Instrumentation

• ACQUITY UPLC I-Class PLUS System
• ACQUITY UPLC BEH C18 Column (100 × 2.1 mm, 1.7 µm)
• ACQUITY PDA Detector
• ACQUITY RDa Detector (benchtop TOF)
• UNIFI Scientific Information System (v1.9) with waters_connect platform

Main Results and Discussion

Targeted Workflow:

• Screened for five literature-reported impurities (I–V).
• Impurities II and III formed under acidic and oxidative stress; impurity V under basic stress only.
• Detected a novel oxidation product at m/z 478.1746 ([M+O₂]⁺) under oxidative conditions.
• Automatic library matching and fragment visualization provided confident identification.

Non-Targeted Workflow:

• In silico prediction of plausible transformations from the glipizide structure.
• Fragment libraries imported into UNIFI to screen high-energy spectra.
• Confirmation of the unknown m/z 478.1746 species as [M+O₂]⁺ via shared fragment ions with the parent API.

Trend Analysis:

• Trend plots illustrated API depletion and impurity formation over time and across stress types.
• Acidic and oxidative conditions drove impurities II and III; basic conditions produced impurity V exclusively.

Benefits and Practical Applications of the Method

• Routine HRMS access for both novice and expert users without specialized setup.
• Automated detection and visualization of degradants and fragment ions.
• Stepwise UNIFI workflows for rapid screening and detailed profiling.
• 21 CFR Part 11–compliant waters_connect platform supports end-to-end regulatory workflows.

Future Trends and Opportunities

Integration of benchtop HRMS with intelligent software will continue to democratize forced degradation studies. Advances may include machine-learning–driven fragmentation prediction, cloud-based collaborative libraries, and deeper automation of regulatory reporting. Such developments will further accelerate stability assessments and reduce time to market.

Conclusion

The combination of the ACQUITY RDa Detector, UPLC I-Class PLUS System, PDA detection, and UNIFI workflows offers an effective, routine solution for both targeted and non-targeted forced degradation studies. Automated setup, accurate mass data, and simultaneous low/high energy acquisition facilitate confident impurity identification and pathway profiling without the need for dedicated HRMS laboratories.

References

• Bansal G, Singh M, Jindal KC, Singh S. LC and LC-MS Study on Establishment of Degradation Pathway of Glipizide under Forced Decomposition Conditions. Journal of Chromatographic Science. 2008;46:510–517.
• International Conference on Harmonization. Q1A (R2): Stability Testing of New Drug Substances and Products. 2003.
• FDA Guidance for Industry. INDs for Phase II and III Studies—Chemistry, Manufacturing, and Controls Information. 2003.
• Blessy M, Patel RD, Prajapati PN, Agrawal YK. Development of Forced Degradation and Stability Indicating Studies of Drugs—A Review. Journal of Pharmaceutical Analysis. 2014;4(3):159–165.