Liquid Chromatographic Method for Irinotecan Estimation: Screening of P-gp Modulators

Area of Science:

• Analytical Chemistry
• Pharmacokinetics
• Biopharmaceutics

Background:

• Irinotecan is a vital chemotherapy drug, but its absorption and transport are influenced by efflux pumps like P-glycoprotein (P-gp).
• Assessing irinotecan's permeability in physiological conditions is essential for optimizing its therapeutic efficacy.
• Understanding the impact of P-gp modulators on irinotecan transport requires a reliable analytical method.

Purpose of the Study:

• To develop and validate a simple, sensitive, robust, and reliable High-Performance Liquid Chromatography (HPLC) method.
• To quantify irinotecan in physiological media for permeability assessment using an everted gut sac model.
• To evaluate the effect of various P-gp modulators on irinotecan permeability.

Main Methods:

• Separation of irinotecan was achieved using a C18 column with a mobile phase of acetonitrile and a sodium dihydrogen phosphate buffer (pH 3).
• Analysis was performed using a Photodiode Array (PDA) detector at 254.9 nm with a flow rate of 1 ml/min.
• The method's linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, specificity, and robustness were rigorously evaluated.

Main Results:

• The HPLC method demonstrated excellent linearity (r² = 0.9999) over a concentration range of 0.060–10.0 µg/ml.
• The LOD and LOQ were determined to be approximately 0.020 µg/ml and 0.060 µg/ml, respectively.
• The method exhibited high precision (RSD < 1.5% for repeatability, <2.55% for intermediate precision), accuracy (96.11–101.51% recovery), specificity, and robustness (% RSD < 2).

Conclusions:

• A validated, simple, sensitive, and robust HPLC method for irinotecan quantification in physiological media has been successfully developed.
• This method is suitable for assessing irinotecan permeability and evaluating the effects of diverse P-gp modulators.
• The developed assay provides a reliable tool for pharmacokinetic and drug interaction studies involving irinotecan.