Novel Stability‐Indicating Reversed‐Phase High‐Performance Liquid Chromatography Method Development and Validation for Quantification of Celecoxib in Marketed Formulations and Transfersomes: Quality by Design‐Driven Optimization

ABSTRACT Celecoxib is a nonsteroidal anti‐inflammatory drug that selectively inhibits the cyclooxygenase‐2 enzyme. It plays vital role in the treatment of osteoarthritis, rheumatoid arthritis, juvenile rheumatoid arthritis, ankylosing spondylitis, initial dysmenorrhea, and certain cancers. Its extensive therapeutic application necessitates a highly specific, sensitive, and reproducible analytical method for accurate quantification. The present research develops and validates the quality by design‐assisted stability‐indicating reverse‐phase high‐performance liquid chromatography approach to quantify celecoxib into bulk, marketed products, and formulated transfersome nanoformulation. Central composite design was adopted to optimize the organic phase composition (%) and rate of flow, with retention time, number of theoretical plates, and tailing factor functioning the vital response parameters. Chromatographic separation was performed using an isocratic mobile phase constituted with acetonitrile and 0.01% orthophosphoric acid (65:35 v/v) employing a Phenomenex Luna C18 column (250 mm × 4.6 mm, 5 µm) with lambda max of 251 nm and flow rate of 1.0 mL/min. A well‐defined celecoxib peak was detected at 8.316 min. The method revealed remarkable linearity within concentrations ranging from 0.1 to 10 µg/mL and had R 2 of 0.9996. Detection limit was 0.195 µg/mL, whereas quantification limit was 0.592 µg/mL. Validation assessments accomplished in adherence with International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use Q2(R2) guidelines exhibited the accuracy (99.00%–101.15% recovery), precision, and robustness, with relative standard deviation constantly less than 2%. Additionally, degradation studies under acid, base, oxidation, heating, and photolytic circumstances displayed the method stability‐indicating potential, as the peak of celecoxib remained unaltered and well‐resolved, with no notable retention time shifts or disruption by substances of decay. Established method demonstrated that it is an incredibly legitimate analytical tool for regular celecoxib quantification. Its productive utilization in pharmaceutical products and transfersome nanoformulation illustrates its ability to serve as a benchmark method for formulation optimization and quality control in pharmaceutical industry.