Development and Validation of RP-HPLC Method for Simultaneous Assay and Dissolution Quantitative Analysis of Pitavastatin-Fenofibrate Complex Dual-Layered Tablets

A robust and unified reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the simultaneous quantitative analysis of pitavastatin calcium and fenofibrate in dual-layer tablet formulations. Although individual analytical methods for each active pharmaceutical ingredient have been reported, a single analytical procedure applicable to both assay and dissolution testing of this fixed-dose combination has not been sufficiently established. In this study, a single RP-HPLC method was optimized to support both quality control purposes, thereby improving analytical efficiency and reducing method-related variability. Chromatographic separation was achieved using a C18 column (4.6 × 150 mm, 5 µm) under isocratic conditions, with a flow rate of 1.1 mL/min, an injection volume of 40 µL, and UV detection at 245 nm. The total run time was 10 min. The method was validated in accordance with ICH guideline Q2(R1) for system suitability, specificity, linearity and range, accuracy, precision (repeatability and intermediate precision), limits of detection and quantitation, and solution stability. Validation was conducted for both assay and dissolution samples using the same chromatographic conditions. The method demonstrated excellent linearity over the validated concentration ranges for both assay and dissolution analyses (r2 ≥ 0.99). Accuracy and precision results satisfied the predefined acceptance criteria for assay (98.0–102.0%) and dissolution-related quantification (95.0–105%), with relative standard deviation values not exceeding 2.0%. The method showed adequate sensitivity, specificity, and solution stability, confirming its suitability for routine analysis. Application of the validated method to finished dual-layer tablets demonstrated reliable assay results and clearly distinguished the rapid dissolution of pitavastatin calcium from the delayed dissolution behavior of fenofibrate. Overall, the developed RP-HPLC method provides a validated analytical platform capable of supporting both assay and dissolution testing of pitavastatin–fenofibrate dual-layer tablets. Beyond routine validation, the proposed analytical framework demonstrates how a single chromatographic condition can support multiple quality attributes, offering an analytically integrated approach for supporting multiple quality attributes in complex combination drug products.