Development and Validation of Novel RP-HPLC Method for the Simultaneous Estimation of Capecitabine and Thymoquinone in the Biodegradable Nanoparticles using Full Factorial Design

Abstract An innovative RP-HPLC technique was devised to simultaneously quantify thymoquinone (TQ) and capecitabine (CAP) in newly designed polymeric nanoparticles. A unique chromatographic approach was created, optimized and validated using Design-Expert® (design of experiment) in compliance with ICH requirements. A 24 factorial design examined the influence of variables on method responses. The method found linear between 0.25 and 16 μg/mL, with an R2 value of 0.999. The detection and quantification limits for CAP were 0.05 and 0.16 μg/mL, respectively, and 0.12 and 0.38 μg/mL for TQ, respectively, and 97–100% recovery in plain drug solution and 100–102% in nanoformulation were achieved. A purposeful modification examined by analysis of variance revealed that the experimental model was significant (P = 0.0001). The total drug content in nanoformulation was 8.68 mg, and the entrapment efficiency was 84.79%. Based on the findings, it is possible to infer that the use of the Quality by Design methodology resulted in the development of a more accurate technique capable of producing consistent, dependable, high-quality data and precise in quantifying CAP and TQ in bulk and nanoparticulate systems.