A Validated Reverse‐Phase High‐Performance Liquid Chromatography Method for Concurrent Quantification of Ibuprofen and Resveratrol in Drug‐loaded Mesoporous Silica Nanoparticles

ABSTRACT The co‐delivery of anti‐inflammatory and antioxidant agents presents a promising strategy for enhancing therapeutic efficacy in the management of osteoarthritis through synergistic mechanisms. This study developed and validated a robust and reproducible reverse‐phase high‐performance liquid chromatography (RP‐HPLC) method for the simultaneous quantification of ibuprofen (IF) and resveratrol (RS) co‐encapsulated in mesoporous silica nanoparticles (MSNs). Chromatographic separation was achieved on a Hypersil GOLD C18 column using a gradient mobile phase composed of 10 mM ammonium acetate buffer (pH 5.3) and methanol: ammonium acetate buffer (9:1, v/v) at a flow rate of 1.0 mL/min. The column oven was maintained at 30°C, with an injection volume of 10 µL, and detection was carried out at an isosbestic wavelength of 223 nm. Retention times for IF and RS were observed at 6.03 and 9.85 min, respectively. The method was validated in accordance with ICH Q2(R1) guidelines, demonstrating excellent specificity, system suitability, linearity, accuracy, precision, robustness and sensitivity, with well‐defined limit of detection and limit of quantification values. Additionally, the method was successfully applied to forced degradation studies under acidic, alkaline, oxidative, thermal and photolytic conditions, confirming its stability‐indicating capability. The validated RP‐HPLC method was further utilised to quantify drug loading efficiency in IF and RS co‐loaded MSNs, highlighting its applicability in routine analysis for advanced drug delivery systems.