Development and Validation of a Novel HPLC Method to Analyse Metabolic Reaction Products Catalysed by the CYP3A2 Isoform: In Vitro Inhibition of CYP3A2 Enzyme Activity by Aspirin (Drugs Often Used Together in COVID-19 Treatment)

Comprehensive analysis of Aspirin and Apixaban: thedevelopment, validation, and forced degradation studies of bulk drugs and in-house capsule formulations using the RP-HPLC method

OBJECTIVES

This study aimed to develop a robust Reverse Phase-High-Performance Liquid Chromatography (RP-HPLC) method for simultaneous determination of Aspirin (ASP) and Apixaban (API) in bulk and in-house capsule formulations.

METHODS

The separation was conducted on a Phenomenex Luna C18 column using a Shimadzu LC20AT High-performance liquid chromatography (HPLC) system. The mobile phase consisted of 40:60 Acetonitrile (ACN): phosphate buffer (pH 4) modified by O-Phosphoric Acid (OPA). The parameters included a flow rate of 1 ml/min, a column temperature of 30°C, and Ultra-Violet (UV) detection at 227 nm. Method validation encompassed linearity, precision (Intraday and Interday), accuracy (% Recovery), and sensitivity (Limit of Detection (LOD) and Limit of Quantification (LOQ)). Stability testing followed The International Council for Harmonization (ICH) guidelines.

RESULTS

The developed method demonstrated reliable separation of Aspirin and Apixaban with retention times of 5.37 min and 7.10 min, respectively. It exhibited linearity over the concentration ranges of 50-300 μg/mL for Aspirin and 5-15 μg/mL for Apixaban. The recovery percentage ranged from 90.02% to 101% for Aspirin and 98.18% to 101.18% for Apixaban. LOD and LOQ were determined as 0.84 μg/mL and 2.55 μg/mL for Aspirin, and 0.41 μg/mL and 1.24 μg/mL for Apixaban, respectively. Stability testing confirmed the method's robustness under various stress conditions.

CONCLUSIONS

The validated RP-HPLC method offers a reliable tool for routine analysis of Aspirin and Apixaban in pharmaceutical formulations, highlighting its potential for combined dosage applications and routine quality control.

Potential Effects of Ibuprofen, Remdesivir and Omeprazole on Dexamethasone Metabolism in Control Sprague Dawley Male Rat Liver Microsomes (Drugs Often Used Together Alongside COVID-19 Treatment)

The role of individual cytochrome P450 (CYPs) responsible for the drug metabolism can be determined through their chemical inhibition. During the pandemic, dexamethasone and remdesivir with omeprazole were used for the treatment of COVID-19, while Ibuprofen was taken to treat the symptoms of fever and headache. This study aimed to examine the potency of ibuprofen remdesivir, and omeprazole as inhibitors of cytochrome P450s using rat liver microsomes in vitro. Dexamethasone a corticosteroid, sometimes used to reduce the body’s immune response in the treatment of COVID-19, was used as a probe substrate and the three inhibitors were added to the incubation system at different concentrations and analysed by a validated High Performance Liquid Chromatography (HPLC) method. The CYP3A2 isoenzyme is responsible for dexamethasone metabolism in vitro. The results showed that ibuprofen acts as a non-competitive inhibitor for CYP3A2 activity with K_i = 224.981 ± 1.854 µM and IC₅₀ = 230.552 ± 2.020 µM, although remdesivir showed a mixed inhibition pattern with a K_i = 22.504 ± 0.008 µM and IC₅₀ = 45.007 ± 0.016 µM. Additionally, omeprazole uncompetitively inhibits dexamethasone metabolism by the CYP3A2 enzyme activity with a K_i = 39.175 ± 0.230 µM and IC₅₀ = 78.351 ± 0.460 µM. These results suggest that the tested inhibitors would not exert a significant effect on the CYP3A2 isoenzyme responsible for the co-administered dexamethasone drug’s metabolism in vivo.