As part of the method development,the injection volume as a critical quality attribute in fast fused-core chromatography was evaluated.Spilanthol,a pharmaceutically interesting Nalkylamide currently under investigation in our laboratory,was chosen as the model compound.Spilanthol was dissolved in both PBS and MeOH/H2O(70/30,v/v)and subsequently analyzed using a fused-core system hereby selecting fve chromatographic characteristics(retention time,area,height,theoretical plates and symmetry factor)as responses.We demonstrated that the injection volume signifcantly influenced both the qualitative and quantitative performance of fused-core chromatography,a phenomenon which is confounded with the nature of the used sample solvent.From 2 mL up to 100 mL injection volume with PBS as solvent,the symmetry factor decreased favorably by 20%.Moreover,the theoretical plates and the quantitative parameters(area and height)increased up to 30%.On the contrary,in this injection volume range,the theoretical plates for the methanol-based samples decreased by more than 60%,while the symmetry factor increased and the height decreased,both by 30%.The injection volume is thus a critical and often overlooked parameter in fused-core method description and validation. As part of the method development, the injection volume as a critical quality attribute in fast fused-core chromatography was as.Spilanthol, a pharmaceutically interesting Nalkylamide currently under investigation in our laboratory, was chosen as the model compound. Spilanthol was dissolved in both PBS and MeOH / H2O (70/30, v / v) and subsequently analyzed using a fused-core system of selecting fve chromatographic characteristics (retention time, area, height, theoretical plates and symmetry factor) as responses. We demonstrated that the injection volume signifcantly influenced both the qualitative and quantitative performance of fused-core chromatography, a phenomenon which is confounded with the nature of the used sample solvent. From 2 mL up to 100 mL injection volume with PBS as solvent, the symmetry factor favored by 20% . Moreover, the theoretical plates and the quantitative parameters (area and height) increased up to 30%. On the contrary, in this injection volume range, the theoret The plastic plates for the methanol-based samples decreased by more than 60%, while the symmetry factor increased and the height decreased, both by 30%. The injection volume was thus critical and often overlooked parameters in fused-core method description and validation.