QbD BASED RP-HPLC METHOD DEVELOPMENT FOR FIVE FLUOROQUINOLONE ANTI-BACTERIALS – THROUGH CREATION OF DESIGN SPACE FOR CRITICAL ATTRIBUTES

Quality by Design (QbD) has become an important concept for the pharmaceutical industry, and ICH recommends this concept through the Guideline Q8 (R2) wherein if the method is proved to be rugged and robust within the limits of a Design Space then approval may be requested for such a Design Space, and the method does not need redevelopment, revalidation, and reapproval during transfers, thereby saving significant time and resources. In this study, the QbD approach was used to develop a reverse-phase–high-performance liquid chromatography (RP–HPLC) method that could be applied for the estimation of several antibacterial agents of the fluoroquinolone group. The method was applied to five selected fluoroquinolones, namely, ciprofloxacin, levofloxacin, norfloxacin, moxifloxacin, and ofloxacin. The method developed used C18 column of make Phenomenex (250 mm × 4.6 mm, 5 μm) with mobile phase comprising of methanol and phosphate buffer (pH 3.0) in the proportion 70:30 at a flow rate of 1.25 ml/min and detection was carried out using a PDA detector at 294 nm. The method while being validated as per ICH guidelines, using ANOVA, simultaneously created a design space which set limits for critical attributes affecting the robustness. Any variations in these parameters within the design space does not affect method performance, making the method easily transferrable.