Application of AQbD principles on the development of a stability-indicating HPLC method for the determination of acetylsalicylic acid, ramipril and atorvastatin in their fixed-dose polypills

In this study, an analytical quality by design approach was proposed for the development of a stability-indicating HPLC method for the determination of acetylsalicylic acid, ramipril and atorvastatin in their fixed-dose polypills. The structures, retention and the forced degradation studies of each drug served as useful prior knowledge. Using risk assessment and screen design, three critical method parameters (buffer pH, gradient slope and % CH₃OH initial content) were defined and optimized using a Box-Behnken response surface methodology. The stability-indicating features of the proposed method are assessed through forced degradation studies. The chromatographic separation of the analytes was carried out with a gradient mode using 10 mM phosphate buffer (pH 2.3) and methanol on a C₁₈ analytical column. The method operable design region was approved by the establishment of a robust zone using Monte Carlo simulation and capability analysis. The determination coefficients (<i>R</i>²) were higher than 0.9939. The proposed method indicated good precision (RSD < 7.7%) and the accuracy expressed as average % relative recovery ranged between 91.4-106.7%. The developed analytical scheme was successfully applied to quantify the selected APIs in the commercially available polypill Trinomia® capsules. The dosage uniformity of the drug-containing formulations was evaluated.