Stability-Focused Nanoparticle Development: Applying Particle Size Stability as a Response Factor in the Design of Experiments

Particle size stability is an important quality parameter of nanoparticle delivery systems and is usually investigated at the end of formulation development. It has not been used as a response factor in the design of experiments (DoE). This study aimed to evaluate the use of particle size stability as a response factor in a DoE, allowing researchers to obtain knowledge on formulation stability early on during formulation development. Nanostructured lipid carriers loaded with copaiba oil were used as the test formulation. The experimental design consisted of 14 runs, including one central point in sextuplicate, and the data were analyzed using multiple linear regression analysis. By using predetermined parameters of size variation, PdI, and analysis quality, a model that measures stability in days offered statistically significant predictors and enabled formulation optimization. The results demonstrate the applicability of DoE for optimizing nanoparticle formulations based on particle size stability as a response factor.