In the manufacturing sector, syringe production faces a number of challenges due to the complexity of the injection process and the configuration of the machinery involved. In particular, 10 mL 2P syringes may have variations in their piston, increasing the risk of leakage and reducing their reliability. The overall objective is to improve the quality of two-part syringes through the design of experiments and the response surface methodology, supported by a quantitative analysis of the factors causing the non-conformities in the piston diameters of the 10 mL 2P syringes detected during inspection. It will be carried out in three stages: identification of the significant factors affecting the diameter of the pistons; determination of the optimal conditions for machine configuration and formulation of a mathematical model that guarantees compliance with quality standards. The results show that injection time is the most significant factor, accounting for 83% of the effect on piston diameter, followed by injection pressure with 13%, with minimal effects of other factors. The study achieved a Cp of 1.21 for piston diameter and reduced non-conforming products by 32%.