Analysis of Captopril tablet

Significance of the Topic

Captopril is a widely used ACE inhibitor for hypertension treatment. Accurate quantification of captopril and its oxidation product captopril disulfide is essential to guarantee drug efficacy, safety, and regulatory compliance in pharmaceutical quality control.

Objectives and Overview of the Study

This application note describes the development and validation of a reversed-phase HPLC method using a Shim-pack VP-ODS column for simultaneous determination of captopril and captopril disulfide in tablet formulations. The goal is to evaluate the method s separation performance, sensitivity, and reproducibility for routine analysis.

Methodology

Sample pretreatment steps

• Grind twenty tablets to a fine powder
• Weigh 25 mg of powder and transfer to a centrifuge tube
• Add 25 mL of mobile phase, sonicate for 15 minutes
• Centrifuge and collect the clear supernatant for injection

Chromatographic conditions

• Column: Shim-pack VP-ODS (250 mm × 4.6 mm I.D., 5 μm)
• Mobile phase: methanol : water : phosphoric acid = 550 : 450 : 0.5 (v/v/v)
• Flow rate: 1.0 mL/min
• Column temperature: 40 °C
• Injection volume: 20 μL
• Detection: UV at 220 nm

Used Instrumentation

• Shim-pack VP-ODS analytical column (Shimadzu)
• High-performance liquid chromatography system with autosampler and column oven
• UV detector set at 220 nm
• Sonicator and centrifuge for sample preparation

Results and Discussion

Chromatograms of the standard mix and the tablet extract showed clear baseline separation of captopril and captopril disulfide with no interfering peaks from excipients. The method exhibited a linear response for the target compounds at the tested concentrations, demonstrating good precision and accuracy for tablet analysis.

Benefits and Practical Applications

The proposed HPLC procedure is robust and reproducible, making it well suited for pharmaceutical quality control laboratories. It enables precise dosage verification and impurity monitoring to support regulatory requirements for hypertension medications.

Future Trends and Applications

• Coupling with mass spectrometry for enhanced selectivity and lower detection limits
• Adoption of UHPLC formats to reduce run time and solvent consumption
• Extension to other ACE inhibitors or combination drug products
• Implementation of greener mobile phases to minimize environmental impact

Conclusion

A straightforward reversed-phase HPLC method using a Shim-pack VP-ODS column successfully quantifies captopril and its disulfide impurity in tablet forms. Its simplicity, reproducibility, and compliance with quality control standards make it a valuable tool for pharmaceutical analysis.