Speaker
Description
Liposomal formulations have attracted considerable interest as sustained drug delivery systems for local anesthetics because they can prolong drug release and potentially reduce dosing frequency. Accurate determination of encapsulation efficiency (EE) and in vitro drug release is therefore essential for evaluating formulation performance. This study validated and applied a reversed-phase high-performance liquid chromatography (RP-HPLC) method for quantitative analysis of ropivacaine in liposomal formulations. Chromatographic separation was achieved using a Purospher Star RP-18 C18 column (150 × 4.6 mm, 5 µm) with a mobile phase consisting of acetonitrile:methanol:water (40:30:30, v/v/v) containing 0.1% triethanolamine at a flow rate of 1.5 mL/min. Detection was performed at 240 nm with an injection volume of 20 µL. The analytical method was validated according to specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision. No interference from the liposomal matrix was observed at the retention time of ropivacaine (7.48 min), confirming good specificity. Excellent linearity was obtained over the concentration range of 5–200 ppm (r = 0.9997), with an LOD of 7.77 ppm and an LOQ of 23.39 ppm. Recovery values ranged from 98.02% to 101.91%, while relative standard deviation (%RSD) values remained below 2%, demonstrating good accuracy and precision. The validated RP-HPLC method was successfully applied to determine encapsulation efficiency and evaluate the in vitro release profile of liposomal ropivacaine formulations. These results demonstrate that the proposed method provides a reliable and reproducible analytical approach for quantitative evaluation of liposomal ropivacaine during formulation development and quality assessment.
