A Reliable and Effective UPLC-MS/MS Method for the Determination of Oprozomib in Rat Plasma

by Selleckchem | Nov 10 2023

Oprozomib, as a second-generation orally bioavailable protease inhibitor (PI), is undergoing clinical evaluation for the treatment of haematological malignancies. In relapsed refractory multiple myeloma (RRMM) patients, oprozomib has shown good efficacy as a single agent or combination therapy. In this experiment, our purpose was to validate a sensitive and rapid method for the determination of oprozomib concentration in rat plasma by ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The samples were treated with acetonitrile as the precipitant and separated by gradient elution using a Waters Acquity UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm). Using the selective reaction monitoring (SRM) method, the measurement was finished with the ion transitions of m/z 533.18 ⟶ 199.01 for oprozomib and m/z 493.03 ⟶ 112.03 for tepotinib (internal standard, IS), respectively. Meanwhile, acetonitrile and 0.1% formic acid aqueous solution were used as the mobile phase, and the flow rate was 0.3 mL/min. The lower limit of quantification (LLOQ) of the method was 1.0 ng/mL, and the linear relationship was good in the range of 1.0-100 ng/mL. In addition, the precision of four concentration levels was determined with the values of 3.1-7.3% and the accuracy was from -14.9% to 12.9%. Moreover, the recovery was determined to be from 85.1% to 96.1%, and the values of matrix effect were no more than 110.4%. The optimized UPLC-MS/MS method was also suitable for the pharmacokinetic study of rats after a single oral administration of 21 mg/kg oprozomib.

Comments:

It appears you've provided information about a scientific experiment involving the determination of oprozomib concentration in rat plasma using ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Here's a breakdown of the key points from your description:

**Purpose of the Experiment:**
- The experiment aimed to validate a sensitive and rapid method for quantifying oprozomib concentration in rat plasma.
- Oprozomib is a second-generation orally bioavailable protease inhibitor being evaluated for the treatment of haematological malignancies, particularly in relapsed refractory multiple myeloma (RRMM) patients.

**Experimental Details:**
- **Sample Treatment:** The rat plasma samples were treated with acetonitrile as a precipitant.
- **Column:** A Waters Acquity UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) was used for separation.
- **Analytical Method:** The selective reaction monitoring (SRM) method was employed.
- **Ion Transitions:** Oprozomib was monitored at m/z 533.18 ⟶ 199.01, and tepotinib was used as the internal standard (IS) with ion transitions at m/z 493.03 ⟶ 112.03.
- **Mobile Phase:** A mixture of acetonitrile and 0.1% formic acid aqueous solution was used as the mobile phase.
- **Flow Rate:** The flow rate was set at 0.3 mL/min.
- **Calibration Range:** The linear relationship for oprozomib concentration was established in the range of 1.0-100 ng/mL.
- **Lower Limit of Quantification (LLOQ):** The LLOQ of the method was 1.0 ng/mL.

**Method Validation:**
- **Precision:** The precision at four concentration levels ranged from 3.1% to 7.3%.
- **Accuracy:** The accuracy was determined to be within the range of -14.9% to 12.9%.
- **Recovery:** The recovery rate ranged from 85.1% to 96.1%.
- **Matrix Effect:** The values of the matrix effect were no more than 110.4%.

**Application:** The validated UPLC-MS/MS method was found to be suitable for studying the pharmacokinetics of oprozomib in rats after a single oral administration of 21 mg/kg oprozomib.

This method provides a reliable and sensitive means of quantifying oprozomib concentrations in rat plasma, which is essential for pharmacokinetic studies and evaluating its efficacy in preclinical research.